Single-crystal(SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors(PDs);however, their applications in large-area imaging and wearable electronics face limita...Single-crystal(SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors(PDs);however, their applications in large-area imaging and wearable electronics face limitations due to size constraints and mechanical inflexibility. To address these challenges, this study develops a hybrid composite structure— polycrystalline powder(PCP) matrix(PCPM)—by strategically homogenizing 20 μm PCPs within a poly(methyl methacrylate) matrix. Such a configuration enables the formation of densely packed PCP microstructures while maintaining electric conductivity and mechanical flexibility. In the single-photon regime, responsivity(R) and external quantum efficiency(EQE) decline by 50%, with concurrent 3–4-fold enhancements in the On/Off ratio and 12–16-fold improvements in specific detectivity(D), compared with those of SC counterparts. Notably, in the two-photon regime, R and EQE exhibit a 2–3-fold increase, and the On/Off ratio and D exhibit 12–16-fold improvements. The PCPM configuration enables the high-repetitionrate wafer-scale fabrication of active layers for imaging PDs and provides exceptional mechanical flexibility and self-recovery. These findings establish PCPMs as a scalable platform for next-generation perovskite wearable electronics.展开更多
Photodetectors can convert light energy into electrical signals,so are widely used in photovoltaics,photon counting,monitoring,and imaging.Photodetectors are easy to prepare high-resolution photochips because of their...Photodetectors can convert light energy into electrical signals,so are widely used in photovoltaics,photon counting,monitoring,and imaging.Photodetectors are easy to prepare high-resolution photochips because of their small size unit integration.However,these photodetector units often exhibit poor photoelectric performance due to material defects and inadequate structures,which greatly limit the functions of devices.Designing modification strategies and micro-/nanostructures can compensate for defects,adjust the bandgap,and develop novel quantum structures,which consequently optimize photovoltaic units and revolutionize optoelectronic devices.Here,this paper aims to comprehensively elaborate on the surface/interface engineering scheme of micro-/nano-photodetectors.It starts from the fundamentals of photodetectors,such as principles,types,and parameters,and describes the influence of material selection,manufacturing techniques,and post-processing.Then,we analyse in detail the great influence of surface/interface engineering on the performance of photovoltaic devices,including surface/interface modification and micro-/nanostructural design.Finally,the applications and prospects of optoelectronic devices in various fields such as miniaturization of electronic devices,robotics,and human–computer interaction are shown.展开更多
The development of optoelectronic technologies demands photodetectors with miniaturization,broadband operation,high sensitivity,and low power consumption.Although 2D van der Waals(vd W)heterostructures are promising c...The development of optoelectronic technologies demands photodetectors with miniaturization,broadband operation,high sensitivity,and low power consumption.Although 2D van der Waals(vd W)heterostructures are promising candidates due to their built-in electric fields,ultrafast photocarrier separation,and tunable bandgaps,defect states limit their performance.Therefore,the modulation of the optoelectronic properties in such heterostructures is imperative.Surface charge transfer doping(SCTD)has emerged as a promising strategy for non-destructive modulation of electronic and optoelectronic characteristics in two-dimensional materials.In this work,we demonstrate the construction of high-performance p-i-n vertical heterojunction photodetectors through SCTD of MoTe_(2)/ReS_(2)heterostructure using p-type F_(4)-TCNQ.Systematic characterization reveals that the interfacial doping process effectively amplifies the built-in electric field,enhancing photogenerated carrier separation efficiency.Compared to the pristine heterojunction device,the doped photodetector exhibits remarkable visible to nearinfrared(635-1064 nm)performance.Particularly under 1064 nm illumination at zero bias,the device achieves a responsivity of 2.86 A/W and specific detectivity of 1.41×10^(12)Jones.Notably,the external quantum efficiency reaches an exceptional value of 334%compared to the initial 11.5%,while maintaining ultrafast response characteristics with rise/fall times of 11.6/15.6μs.This work provides new insights into interface engineering through molecular doping for developing high-performance vd W optoelectronic devices.展开更多
In the era of big data and artificial intelligence,optical neural networks(ONNs)have emerged as a promising alternative to conventional electronic approaches,offering superior parallelism,ultrafast processing speeds,a...In the era of big data and artificial intelligence,optical neural networks(ONNs)have emerged as a promising alternative to conventional electronic approaches,offering superior parallelism,ultrafast processing speeds,and high energy efficiency[1-3].However,a major bottleneck in the practical implementation of ONNs is the absence of effective nonlinear activation functions.Self-driven photodetectors have emerged as versatile optical to electrical converters,opening innovative avenues for energy-effective and flexibly integrated activation functions in ONNs through their reconfigurable optoelectronic nonlinearity.展开更多
The weak interlayer van der Waals(vdW) interactions in two-dimensional(2D) vdW materials enable sliding ferroelectricity as an effective strategy for modulating their intrinsic properties. In this work, we systematica...The weak interlayer van der Waals(vdW) interactions in two-dimensional(2D) vdW materials enable sliding ferroelectricity as an effective strategy for modulating their intrinsic properties. In this work, we systematically investigate the influence of interlayer sliding on the electronic behavior of PtSe_(2) using density functional theory(DFT) calculations. Our results demonstrate that interlayer sliding induces a pronounced photocurrent spanning the short-wavelength infrared to visible spectral ranges. Remarkably, under an applied gate voltage, the sliding ferroelectric PtSe_(2) exhibits anomalously enhanced photovoltaic performance and an ultrahigh extinction ratio.Transmission spectral analysis reveals that this phenomenon originates from band structure modifications driven by energy-level transitions. Furthermore, the observed photocurrent enhancement via sliding ferroelectricity demonstrates universality across diverse platinum-based optoelectronic devices. This study introduces a novel paradigm for tailoring the intrinsic characteristics of 2D vdW semiconductors, expanding the design space for next-generation ferroelectric materials in advanced optoelectronic applications.展开更多
Infrared and terahertz waves constitute pivotal bands within the electromagnetic spectrum,distinguished by their robust penetration capabilities and non-ionizing nature.These wavebands offer the potential for achievin...Infrared and terahertz waves constitute pivotal bands within the electromagnetic spectrum,distinguished by their robust penetration capabilities and non-ionizing nature.These wavebands offer the potential for achieving high-resolution and non-destructive detection methodologies,thereby possessing considerable research significance across diverse domains including communication technologies,biomedical applications,and security screening systems.Two-dimensional materials,owing to their distinctive optoelectronic attributes,have found widespread application in photodetection endeavors.Nonetheless,their efficacy diminishes when tasked with detecting lower photon energies.Furthermore,as the landscape of device integration evolves,two-dimensional materials struggle to align with the stringent demands for device superior performance.Topological materials,with their topologically protected electronic states and non-trivial topological invariants,exhibit quantum anomalous Hall effects and ultra-high carrier mobility,providing a new approach for seeking photosensitive materials for infrared and terahertz photodetectors.This article introduces various types of topological materials and their properties,followed by an explanation of the detection mechanism and performance parameters of photodetectors.Finally,it summarizes the current research status of near-infrared to far-infrared photodetectors and terahertz photodetectors based on topological materials,discussing the challenges faced and future prospects in their development.展开更多
The rapid advancement of nanotechnology has sparked much interest in applying nanoscale perovskite materials for photodetection applications.These materials are promising candidates for next-generation photodetectors(...The rapid advancement of nanotechnology has sparked much interest in applying nanoscale perovskite materials for photodetection applications.These materials are promising candidates for next-generation photodetectors(PDs)due to their unique optoelectronic properties and flexible synthesis routes.This review explores the approaches used in the development and use of optoelectronic devices made of different nanoscale perovskite architectures,including quantum dots,nanosheets,nanorods,nanowires,and nanocrystals.Through a thorough analysis of recent literature,the review also addresses common issues like the mechanisms underlying the degradation of perovskite PDs and offers perspectives on potential solutions to improve stability and scalability that impede widespread implementation.In addition,it highlights that photodetection encompasses the detection of light fields in dimensions other than light intensity and suggests potential avenues for future research to overcome these obstacles and fully realize the potential of nanoscale perovskite materials in state-of-the-art photodetection systems.This review provides a comprehensive overview of nanoscale perovskite PDs and guides future research efforts towards improved performance and wider applicability,making it a valuable resource for researchers.展开更多
Tin(Sn)-lead(Pb)mixed halide perovskites have attracted widespread interest due to their wider re-sponse wavelength and lower toxicity than lead halide perovskites,Among the preparation methods,the two-step method mor...Tin(Sn)-lead(Pb)mixed halide perovskites have attracted widespread interest due to their wider re-sponse wavelength and lower toxicity than lead halide perovskites,Among the preparation methods,the two-step method more easily controls the crystallization rate and is suitable for preparing large-area per-ovskite devices.However,the residual low-conductivity iodide layer in the two-step method can affect carrier transport and device stability,and the different crystallization rates of Sn-and Pb-based per-ovskites may result in poor film quality.Therefore,Sn-Pb mixed perovskites are mainly prepared by a one-step method.Herein,a MAPb_(0.5)Sn_(0.5)I_(3)-based self-powered photodetector without a hole transport layer is fabricated by a two-step method.By adjusting the concentration of the ascorbic acid(AA)addi-tive,the final perovskite film exhibited a pure phase without residues,and the optimal device exhibited a high responsivity(0.276 A W^(-1)),large specific detectivity(2.38×10^(12) Jones),and enhanced stability.This enhancement is mainly attributed to the inhibition of Sn2+oxidation,the control of crystal growth,and the sufficient reaction between organic ammonium salts and bottom halides due to the AA-induced pore structure.展开更多
Flexible photodetectors have garnered significant attention by virtue of their potential applications in environmental monitoring,wearable healthcare,imaging sensing,and portable optical communications.Perovskites sta...Flexible photodetectors have garnered significant attention by virtue of their potential applications in environmental monitoring,wearable healthcare,imaging sensing,and portable optical communications.Perovskites stand out as particularly promising materials for photodetectors,offering exceptional optoelectronic properties,tunable band gaps,low-temperature solution processing,and notable mechanical flexibility.In this review,we explore the latest progress in flexible perovskite photodetectors,emphasizing the strategies developed for photoactive materials and device structures to enhance optoelectronic performance and stability.Additionally,we discuss typical applications of these devices and offer insights into future directions and potential applications.展开更多
High-performance perovskite photodetectors with self-driven characteristic usually need electron/hole transport layers to extract carriers. However, these devices with transport layer structure are prone to result in ...High-performance perovskite photodetectors with self-driven characteristic usually need electron/hole transport layers to extract carriers. However, these devices with transport layer structure are prone to result in a poor perovskite/transport layer interface, which restricts the performance and stability of the device. To solve this problem, this work reports a novel device structure in which perovskite nanowires are in-situ prepared on PbI_(2), which serves as both a reaction raw material and efficient carrier extraction layer. By optimizing the thickness of PbI_(2), nanowire growth time, and ion exchange time, a selfdriven photodetector with an ITO/PbI_(2)/CsPbBr_(3)/carbon structure is constructed. The optimized device achieves excellent performance with the responsivity of 0.33 A/W, the detectivity of as high as 3.52 × 10^(13) Jones. Furthermore, the device can detect the light with its optical power lowered to 0.1 nW/cm^(2). This research provides a new method for preparing perovskite nano/micro devices with simple structure but excellent performance.展开更多
A heterostructure photodetector composed of few-layer NiPS_(3)/WS_(2)is made by using mechanical exfoliation and micro-nano fabrication techniques.The photodetector exhibits a broad-band response wavelengths of rangin...A heterostructure photodetector composed of few-layer NiPS_(3)/WS_(2)is made by using mechanical exfoliation and micro-nano fabrication techniques.The photodetector exhibits a broad-band response wavelengths of ranging of 405 nm and 800 nm.Under the light illumination of 405-nm wavelength and a bias voltage of-2V,the photoresponsivity is 62.6 m A/W and the specific detectivity is 8.59×10^(10)Jones.In addition,the device demonstrates a relatively fast response with rise and fall times of 70 ms and 120 ms.Theoretical calculation suggest that this excellent performance can be ascribed to the type-Ⅱband alignment at the NiPS_3/WS_2 heterostructure interface.展开更多
Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-po...Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.展开更多
A polarization-sensitive and flexible photodetector was fabricated through the precise alignment of perovskite nanowires(NWs)using a brush coating technique.The alignment of the NWs was meticulously examined,consideri...A polarization-sensitive and flexible photodetector was fabricated through the precise alignment of perovskite nanowires(NWs)using a brush coating technique.The alignment of the NWs was meticulously examined,considering various chemical properties of the solvent,such as boiling point,viscosity,and surface tension.Notably,when the NWs were brush-coated with toluene dispersion,the NWs were aligned in higher order than those processed from octane dispersion.The degree of alignment was correlated with the photodetector property.Especially,the well-aligned NW photodetector exhibited a two-fold disparity in current response contingent on the polarization direction.Furthermore,even after enduring 500 bending cycles,the device retained 80%of its photodetector performance.This approach underscores the potential of solution-processed flexible photodetectors for advanced optical applications under dynamic operating conditions.展开更多
β-Ga_(2)O_(3),as one of the important 4th generation semiconductors,is widely used in solar-blind ultraviolet(UV)detectors with a short detection range of 200-280 nm benefiting from its ultra-wide bandgap,strong radi...β-Ga_(2)O_(3),as one of the important 4th generation semiconductors,is widely used in solar-blind ultraviolet(UV)detectors with a short detection range of 200-280 nm benefiting from its ultra-wide bandgap,strong radiation resistance,and excellent chemical and thermal stabilities.Here,a self-powered photodetector(PD)based on an Ag/β-Ga_(2)O_(3) Schottky heterojunction was designed and fabricated.Through a subtle design of electrodes,the pyro-phototronic effect was discovered,which can be coupled to the common photovoltaic effect and further enhance the performance of the PD.Compared to traditional Ga_(2)O_(3)-based PD,the as-used PD exhibited a self-driving property and a broadband response beyond the bandgap lim-itations,ranging from 200 nm(deep UV)to 980 nm(infrared).Moreover,the photoresponse time was greatly shrunk owing to the coupling effect.Under laser irradiation,with a wavelength of 450 nm and a power density of 8 mW cm-2,the photocurrent could be improved by around 41 times compared with the sole photovoltaic effect.Besides,the performances of the Schottky PD were enhanced at both high and low temperatures.The device also possessed long-term working stability.This paper not only re-veals basic physics lying in the 4th generation semiconductor Ga_(2)O_(3) but also sheds light on the multi-encryption transmission of light information using this PD.展开更多
Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityh...Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityhinders further applications.Conversely,all-inorganic perovskites possessexcellent thermal stability,but black-phase all-inorganic perovskite filmusually requires high-temperature annealing steps,which increases energy consumptionand is not conducive to the fabrication of flexible wearable devices.In this work,an unprecedented low-temperature fabrication of stable blackphaseCsPbI3perovskite films is demonstrated by the in situ hydrolysis reactionof diphenylphosphinic chloride additive.The released diphenyl phosphateand chloride ions during the hydrolysis reaction significantly lower the phasetransition temperature and effectively passivate the defects in the perovskitefilms,yielding high-performance photodetectors with a responsivity of 42.1 AW−1 and a detectivity of 1.3×10^(14)Jones.Furthermore,high-fidelity imageand photoplethysmography sensors are demonstrated based on the fabricated flexible wearable photodetectors.This work provides a newperspective for the low-temperature fabrication of large-area all-inorganic perovskite flexible optoelectronic devices.展开更多
All-inorganic lead-free Cs_(2)AgBiBr_(6) double perovskite is a promising semiconductor for photodetection in daily life due to its outstanding photoelectrical properties,non-toxicity,and high stability.Compared with ...All-inorganic lead-free Cs_(2)AgBiBr_(6) double perovskite is a promising semiconductor for photodetection in daily life due to its outstanding photoelectrical properties,non-toxicity,and high stability.Compared with its organic-inorganic hybrid analogs,the fabrication method for Cs_(2)AgBiBr_(6) is not well developed.Solution-processed Cs_(2)AgBiBr_(6) films usually exhibit loosened morphology with small grains,many pin-holes,and abundant nonradiative defects.In particular,the disordered arrangements of Ag/Bi cations are thermodynamically favorable in Cs_(2)AgBiBr_(6),which contribute to the formation of self-trapped excitons and heavily restrict charge transport.Here in this work,a modified green antisolvent engineering strat-egy with phenethyl-ammonium bromide(PEABr)dissolved isopropyl alcohol(IPA)solution is developed to prepare high-quality Cs_(2)AgBiBr_(6) films.The PEABr/IPA treatment results in compact morphology with enlarged grains and promotes the ordered arrangements of Ag/Bi cations with improved charge transport.Through optimization,the target self-powered photodetector exhibits a responsivity of 0.38 AW−1,a spe-cific detectivity of 1.9×10^(12) Jones,a response time of 54/63μs,and a linear dynamic range of 107 dB,which is among the best-performing self-powered photodetectors based on lead-free perovskites.Our work thus provides a facile and green fabrication method for high-performance optoelectronic devices based on eco-friendly Cs_(2)AgBiBr_(6).展开更多
Tin-lead(Sn-Pb)mixed perovskites are extensively investigated in near-infrared(NIR)photodetectors(PDs)owing to their excellent photoelectric performance.However,achieving high-performance Sn-Pb mixed PDs remains chall...Tin-lead(Sn-Pb)mixed perovskites are extensively investigated in near-infrared(NIR)photodetectors(PDs)owing to their excellent photoelectric performance.However,achieving high-performance Sn-Pb mixed PDs remains challenging,primarily because of the rapid crystallization and the susceptibility of Sn^(2+) to oxidation.To ad⁃dress these issues,this study introduces the multifunctional molecules 2,3-difluorobenzenamine(DBM)to modulate the crystallization of Sn-Pb mixed perovskites and retard the oxidation of Sn^(2+),thereby significantly enhancing film quality.Compared with the pristine film,Sn-Pb mixed perovskite films modulated by DBM molecules exhibit a high⁃ly homogeneous morphology,reduced roughness and defect density.The self-powered NIR PDs fabricated with the improved films have a spectral response range from 300 nm to 1100 nm,a peak responsivity of 0.51 A·W^(-1),a spe⁃cific detectivity as high as 2.46×10^(11)Jones within the NIR region(780 nm to 1100 nm),a linear dynamic range ex⁃ceeding 152 dB,and ultrafast rise/fall time of 123/464 ns.Thanks to the outstanding performance of PDs,the fabri⁃cated 5×5 PDs array demonstrates superior imaging ability in the NIR region up to 980 nm.This work advances the development of Sn-Pb mixed perovskites for NIR detection and paves the way for their commercialization.展开更多
Colloidal quantum dots(CQDs)are affected by the quantum confinement effect,which makes their bandgap tunable.This characteristic allows these materials to cover a broader infrared spectrum,providing a costeffective al...Colloidal quantum dots(CQDs)are affected by the quantum confinement effect,which makes their bandgap tunable.This characteristic allows these materials to cover a broader infrared spectrum,providing a costeffective alternative to traditional infrared detector technology.Recently,thanks to the solution processing properties of quantum dots and their ability to integrate with silicon-based readout circuits on a single chip,infrared detectors based on HgTe CQDs have shown great application prospects.However,facing the challenges of vertically stacked photovoltaic devices,such as barrier layer matching and film non-uniformity,most devices integrated with readout circuits still use a planar structure,which limits the efficiency of light absorption and the effective separation and collection of photo-generated carriers.Here,by synthesizing high-quality HgTe CQDs and precisely controlling the interface quality,we have successfully fabricated a photovoltaic detector based on HgTe and ZnO QDs.At a working temperature of 80 K,this detector achieved a low dark current of 5.23×10^(-9)A cm^(-2),a high rectification ratio,and satisfactory detection sensitivity.This work paves a new way for the vertical integration of HgTe CQDs on silicon-based readout circuits,demonstrating their great potential in the field of high-performance infrared detection.展开更多
Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application ...Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application of the organic semiconductor Y6-1O single crystal in photodetection devices.Firstly,Y6-1O single crystal material was prepared on a silicon substrate using solution droplet casting method.The optical properties of Y6-1O material were characterized by polarized optical microscopy,fluorescence spectroscopy,etc.,confirming its highly single crystalline performance and emission properties in the near-infrared region.Phototransistors based on Y6-1O materials with different thicknesses were then fabricated and tested.It was found that the devices exhibited good visible to near-infrared photoresponse,with the maximum photoresponse in the near-infrared region at 785 nm.The photocurrent on/off ratio reaches 10^(2),and photoresponsivity reaches 16 mA/W.It was also found that the spectral response of the device could be regulated by gate voltage as well as the material thickness,providing important conditions for optimizing the performance of near-infrared photodetectors.This study not only demonstrates the excellent performance of organic phototransistors based on Y6-1O single crystal material in near-infrared detection but also provides new ideas and directions for the future development of infrared detectors.展开更多
All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have attracted extensive attention in photoelectric detection for their excellent photoelectric properties and stability.However,the CsPbBr_(3) quantum dot film exh...All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have attracted extensive attention in photoelectric detection for their excellent photoelectric properties and stability.However,the CsPbBr_(3) quantum dot film exhibits a high non-radiative recombination rate,and the mismatch in energy levels with the carbon electrode weakens hole extraction efficiency.These reduces the device's performance.To improve this,a semiconductor photodetector based on fluorine-doped tin oxide(FTO)/dense titanium dioxide(c-TiO_(2))/mesoporous titanium dioxide(m-TiO_(2))/CsPbBr_(3) QDs/CsPbBr_(x)I_(3-x)(x=2,1.5,1)QDs/C struc-ture was studied.By adjusting the Br-:I-ratio,the synthesized CsPbBr_(x)I_(3-x)(x=2,1.5,1)QDs showed an adjustable band gap width of 2.284-2.394 eV.And forming a typeⅡband structure with CsPbBr_(3) QDs,which reduced the valence band offset between the active layer and the carbon electrode,this promoted carrier extraction and reduced non-radiative recombination rate.Compared with the original device(the photosensitive layer is CsPbBr_(3) QDs),the performance of the photodetector based on the CsPbBr_(3) QDs/CsPbBr2I QDs heterostructure is significantly improved,the responsivity(R)increased by 73%,the specific detectivity rate(D^(*))increased from 6.98×10^(12) to 3.19×10^(13) Jones,the on/off ratio reached 106.This study provides a new idea for the development of semiconductor tandem detectors.展开更多
基金supported by the Key Project of the National Key R&D Program of China (Grant No.2022YFA1404500)the National Natural Science Foundation of China (Grant Nos.12434017,62005183)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2025A1515010329)。
文摘Single-crystal(SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors(PDs);however, their applications in large-area imaging and wearable electronics face limitations due to size constraints and mechanical inflexibility. To address these challenges, this study develops a hybrid composite structure— polycrystalline powder(PCP) matrix(PCPM)—by strategically homogenizing 20 μm PCPs within a poly(methyl methacrylate) matrix. Such a configuration enables the formation of densely packed PCP microstructures while maintaining electric conductivity and mechanical flexibility. In the single-photon regime, responsivity(R) and external quantum efficiency(EQE) decline by 50%, with concurrent 3–4-fold enhancements in the On/Off ratio and 12–16-fold improvements in specific detectivity(D), compared with those of SC counterparts. Notably, in the two-photon regime, R and EQE exhibit a 2–3-fold increase, and the On/Off ratio and D exhibit 12–16-fold improvements. The PCPM configuration enables the high-repetitionrate wafer-scale fabrication of active layers for imaging PDs and provides exceptional mechanical flexibility and self-recovery. These findings establish PCPMs as a scalable platform for next-generation perovskite wearable electronics.
文摘Photodetectors can convert light energy into electrical signals,so are widely used in photovoltaics,photon counting,monitoring,and imaging.Photodetectors are easy to prepare high-resolution photochips because of their small size unit integration.However,these photodetector units often exhibit poor photoelectric performance due to material defects and inadequate structures,which greatly limit the functions of devices.Designing modification strategies and micro-/nanostructures can compensate for defects,adjust the bandgap,and develop novel quantum structures,which consequently optimize photovoltaic units and revolutionize optoelectronic devices.Here,this paper aims to comprehensively elaborate on the surface/interface engineering scheme of micro-/nano-photodetectors.It starts from the fundamentals of photodetectors,such as principles,types,and parameters,and describes the influence of material selection,manufacturing techniques,and post-processing.Then,we analyse in detail the great influence of surface/interface engineering on the performance of photovoltaic devices,including surface/interface modification and micro-/nanostructural design.Finally,the applications and prospects of optoelectronic devices in various fields such as miniaturization of electronic devices,robotics,and human–computer interaction are shown.
基金financial support from 2024 Domestic Visiting Scholar Program for Teachers'Professional Development in Universities(Grant No.FX2024022)National Natural Science Foundation of China(Grant No.61904043)。
文摘The development of optoelectronic technologies demands photodetectors with miniaturization,broadband operation,high sensitivity,and low power consumption.Although 2D van der Waals(vd W)heterostructures are promising candidates due to their built-in electric fields,ultrafast photocarrier separation,and tunable bandgaps,defect states limit their performance.Therefore,the modulation of the optoelectronic properties in such heterostructures is imperative.Surface charge transfer doping(SCTD)has emerged as a promising strategy for non-destructive modulation of electronic and optoelectronic characteristics in two-dimensional materials.In this work,we demonstrate the construction of high-performance p-i-n vertical heterojunction photodetectors through SCTD of MoTe_(2)/ReS_(2)heterostructure using p-type F_(4)-TCNQ.Systematic characterization reveals that the interfacial doping process effectively amplifies the built-in electric field,enhancing photogenerated carrier separation efficiency.Compared to the pristine heterojunction device,the doped photodetector exhibits remarkable visible to nearinfrared(635-1064 nm)performance.Particularly under 1064 nm illumination at zero bias,the device achieves a responsivity of 2.86 A/W and specific detectivity of 1.41×10^(12)Jones.Notably,the external quantum efficiency reaches an exceptional value of 334%compared to the initial 11.5%,while maintaining ultrafast response characteristics with rise/fall times of 11.6/15.6μs.This work provides new insights into interface engineering through molecular doping for developing high-performance vd W optoelectronic devices.
基金supported by the National Natural Science Foundation of China(52422107,T2394471,and 62571319)Beijing Nova Program(20240484531)+1 种基金China Postdoctoral Science Foundation(2022M710074)and Open Research Fund Program of Beijing National Research Center for Information Science and Technology(04410304023).
文摘In the era of big data and artificial intelligence,optical neural networks(ONNs)have emerged as a promising alternative to conventional electronic approaches,offering superior parallelism,ultrafast processing speeds,and high energy efficiency[1-3].However,a major bottleneck in the practical implementation of ONNs is the absence of effective nonlinear activation functions.Self-driven photodetectors have emerged as versatile optical to electrical converters,opening innovative avenues for energy-effective and flexibly integrated activation functions in ONNs through their reconfigurable optoelectronic nonlinearity.
基金supported by the National Key Research and Development Program of China (Grant No. 2024YFB3211701)the National Natural Science Foundation of China (Grant Nos. T2222011, 62174026, and 12274234)+1 种基金the National Key Research and Development Program of China (Grant Nos. 2023YFB3611400 and 2019YFA0308000)the Fundamental Research Funds for the Central Universities (Grant No. 242023k30027)。
文摘The weak interlayer van der Waals(vdW) interactions in two-dimensional(2D) vdW materials enable sliding ferroelectricity as an effective strategy for modulating their intrinsic properties. In this work, we systematically investigate the influence of interlayer sliding on the electronic behavior of PtSe_(2) using density functional theory(DFT) calculations. Our results demonstrate that interlayer sliding induces a pronounced photocurrent spanning the short-wavelength infrared to visible spectral ranges. Remarkably, under an applied gate voltage, the sliding ferroelectric PtSe_(2) exhibits anomalously enhanced photovoltaic performance and an ultrahigh extinction ratio.Transmission spectral analysis reveals that this phenomenon originates from band structure modifications driven by energy-level transitions. Furthermore, the observed photocurrent enhancement via sliding ferroelectricity demonstrates universality across diverse platinum-based optoelectronic devices. This study introduces a novel paradigm for tailoring the intrinsic characteristics of 2D vdW semiconductors, expanding the design space for next-generation ferroelectric materials in advanced optoelectronic applications.
基金supported by the National Key R&D Program of China(Grant No.2024YFA1211300)Outstanding Youth Foundation of NSFC(Grant No.62322515)+5 种基金Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Shanghai Natural Science Foundation Project(Grant No.24ZR1493100)International Partnership Program of Chinese Academy of Sciences(Grant No.112GJHZ2024039FN)the support from Analytical Instrumentation Center(#SPST-AIC10112914)Soft Matter Nanofab(#SPST-SMN180827)Quantum Device Lab,Shanghai Tech University。
文摘Infrared and terahertz waves constitute pivotal bands within the electromagnetic spectrum,distinguished by their robust penetration capabilities and non-ionizing nature.These wavebands offer the potential for achieving high-resolution and non-destructive detection methodologies,thereby possessing considerable research significance across diverse domains including communication technologies,biomedical applications,and security screening systems.Two-dimensional materials,owing to their distinctive optoelectronic attributes,have found widespread application in photodetection endeavors.Nonetheless,their efficacy diminishes when tasked with detecting lower photon energies.Furthermore,as the landscape of device integration evolves,two-dimensional materials struggle to align with the stringent demands for device superior performance.Topological materials,with their topologically protected electronic states and non-trivial topological invariants,exhibit quantum anomalous Hall effects and ultra-high carrier mobility,providing a new approach for seeking photosensitive materials for infrared and terahertz photodetectors.This article introduces various types of topological materials and their properties,followed by an explanation of the detection mechanism and performance parameters of photodetectors.Finally,it summarizes the current research status of near-infrared to far-infrared photodetectors and terahertz photodetectors based on topological materials,discussing the challenges faced and future prospects in their development.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.RS-2022–00165798)Anhui Natural Science Foundation(No.2308085MF211)The authors extend their appreciation to the Deanship of Research and Graduate Studies at King Khalid University for funding this work through Large Research Project under Grant Number(R.G.P.2/491/45).
文摘The rapid advancement of nanotechnology has sparked much interest in applying nanoscale perovskite materials for photodetection applications.These materials are promising candidates for next-generation photodetectors(PDs)due to their unique optoelectronic properties and flexible synthesis routes.This review explores the approaches used in the development and use of optoelectronic devices made of different nanoscale perovskite architectures,including quantum dots,nanosheets,nanorods,nanowires,and nanocrystals.Through a thorough analysis of recent literature,the review also addresses common issues like the mechanisms underlying the degradation of perovskite PDs and offers perspectives on potential solutions to improve stability and scalability that impede widespread implementation.In addition,it highlights that photodetection encompasses the detection of light fields in dimensions other than light intensity and suggests potential avenues for future research to overcome these obstacles and fully realize the potential of nanoscale perovskite materials in state-of-the-art photodetection systems.This review provides a comprehensive overview of nanoscale perovskite PDs and guides future research efforts towards improved performance and wider applicability,making it a valuable resource for researchers.
基金supported by the National Natural Science Foun-dation of China(Nos.52025028,52332008,52372214,52202273,and U22A20137)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘Tin(Sn)-lead(Pb)mixed halide perovskites have attracted widespread interest due to their wider re-sponse wavelength and lower toxicity than lead halide perovskites,Among the preparation methods,the two-step method more easily controls the crystallization rate and is suitable for preparing large-area per-ovskite devices.However,the residual low-conductivity iodide layer in the two-step method can affect carrier transport and device stability,and the different crystallization rates of Sn-and Pb-based per-ovskites may result in poor film quality.Therefore,Sn-Pb mixed perovskites are mainly prepared by a one-step method.Herein,a MAPb_(0.5)Sn_(0.5)I_(3)-based self-powered photodetector without a hole transport layer is fabricated by a two-step method.By adjusting the concentration of the ascorbic acid(AA)addi-tive,the final perovskite film exhibited a pure phase without residues,and the optimal device exhibited a high responsivity(0.276 A W^(-1)),large specific detectivity(2.38×10^(12) Jones),and enhanced stability.This enhancement is mainly attributed to the inhibition of Sn2+oxidation,the control of crystal growth,and the sufficient reaction between organic ammonium salts and bottom halides due to the AA-induced pore structure.
基金supported by the grants from the National Key Research and Development Program of China 2023YFC2505900support from State Key Laboratory of Photovoltaic Science and Technology 202401030303.
文摘Flexible photodetectors have garnered significant attention by virtue of their potential applications in environmental monitoring,wearable healthcare,imaging sensing,and portable optical communications.Perovskites stand out as particularly promising materials for photodetectors,offering exceptional optoelectronic properties,tunable band gaps,low-temperature solution processing,and notable mechanical flexibility.In this review,we explore the latest progress in flexible perovskite photodetectors,emphasizing the strategies developed for photoactive materials and device structures to enhance optoelectronic performance and stability.Additionally,we discuss typical applications of these devices and offer insights into future directions and potential applications.
基金financially supported by the National Natural Science Foundation of China (51972101)the Research platforms and projects of Guangdong Universities in 2022 (2022ZDZX1028)Guangdong Provincial Key Laboratory Project (2023KSYS003)。
文摘High-performance perovskite photodetectors with self-driven characteristic usually need electron/hole transport layers to extract carriers. However, these devices with transport layer structure are prone to result in a poor perovskite/transport layer interface, which restricts the performance and stability of the device. To solve this problem, this work reports a novel device structure in which perovskite nanowires are in-situ prepared on PbI_(2), which serves as both a reaction raw material and efficient carrier extraction layer. By optimizing the thickness of PbI_(2), nanowire growth time, and ion exchange time, a selfdriven photodetector with an ITO/PbI_(2)/CsPbBr_(3)/carbon structure is constructed. The optimized device achieves excellent performance with the responsivity of 0.33 A/W, the detectivity of as high as 3.52 × 10^(13) Jones. Furthermore, the device can detect the light with its optical power lowered to 0.1 nW/cm^(2). This research provides a new method for preparing perovskite nano/micro devices with simple structure but excellent performance.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFE0109200)the National Natural Science Foundation of China(Grant Nos.12074013 and 62175210)。
文摘A heterostructure photodetector composed of few-layer NiPS_(3)/WS_(2)is made by using mechanical exfoliation and micro-nano fabrication techniques.The photodetector exhibits a broad-band response wavelengths of ranging of 405 nm and 800 nm.Under the light illumination of 405-nm wavelength and a bias voltage of-2V,the photoresponsivity is 62.6 m A/W and the specific detectivity is 8.59×10^(10)Jones.In addition,the device demonstrates a relatively fast response with rise and fall times of 70 ms and 120 ms.Theoretical calculation suggest that this excellent performance can be ascribed to the type-Ⅱband alignment at the NiPS_3/WS_2 heterostructure interface.
基金supported by the National Natural Science Foundation of China (No. 62204079)the Science and Technology Development Project of Henan Province (Nos.202300410048, 202300410057)+2 种基金the China Postdoctoral Science Foundation (No. 2022M711037)the Intelligence Introduction Plan of Henan Province in 2021 (No. CXJD2021008)Henan University Fund。
文摘Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.
基金supported by a Commercialization Promotion Agency for R&D Outcomes(COMPA)Grant funded by the Korean Government(Ministry of Science and ICT)(No.RS-2023-00304743)the National Research Foundation of Korea(NRF)Grant funded by the Korean Government(MSIT)(No.2022M3J7A1066428)"Regional Innovation Strategy(RIS)"through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(MOE)(No.2023RIS-008).
文摘A polarization-sensitive and flexible photodetector was fabricated through the precise alignment of perovskite nanowires(NWs)using a brush coating technique.The alignment of the NWs was meticulously examined,considering various chemical properties of the solvent,such as boiling point,viscosity,and surface tension.Notably,when the NWs were brush-coated with toluene dispersion,the NWs were aligned in higher order than those processed from octane dispersion.The degree of alignment was correlated with the photodetector property.Especially,the well-aligned NW photodetector exhibited a two-fold disparity in current response contingent on the polarization direction.Furthermore,even after enduring 500 bending cycles,the device retained 80%of its photodetector performance.This approach underscores the potential of solution-processed flexible photodetectors for advanced optical applications under dynamic operating conditions.
基金supported by the National Natural Science Foundation of China(Grant Nos.52192610 and 52192613)the National Key R&D Project from the Minister of Science and Technology(No.2021YFA1201601)the CAS-TWAS President’s Fellow-ship(A.B).
文摘β-Ga_(2)O_(3),as one of the important 4th generation semiconductors,is widely used in solar-blind ultraviolet(UV)detectors with a short detection range of 200-280 nm benefiting from its ultra-wide bandgap,strong radiation resistance,and excellent chemical and thermal stabilities.Here,a self-powered photodetector(PD)based on an Ag/β-Ga_(2)O_(3) Schottky heterojunction was designed and fabricated.Through a subtle design of electrodes,the pyro-phototronic effect was discovered,which can be coupled to the common photovoltaic effect and further enhance the performance of the PD.Compared to traditional Ga_(2)O_(3)-based PD,the as-used PD exhibited a self-driving property and a broadband response beyond the bandgap lim-itations,ranging from 200 nm(deep UV)to 980 nm(infrared).Moreover,the photoresponse time was greatly shrunk owing to the coupling effect.Under laser irradiation,with a wavelength of 450 nm and a power density of 8 mW cm-2,the photocurrent could be improved by around 41 times compared with the sole photovoltaic effect.Besides,the performances of the Schottky PD were enhanced at both high and low temperatures.The device also possessed long-term working stability.This paper not only re-veals basic physics lying in the 4th generation semiconductor Ga_(2)O_(3) but also sheds light on the multi-encryption transmission of light information using this PD.
基金supported by the National Natural Science Foundation of China(52303257,52321006,T2394480,and T2394484)the National Key R&D Program of China(Grant No.2023YFE0111500)+3 种基金Key Research&Development and Promotion of Special Project(Scientific Problem Tackling)of Henan Province(242102211090)the China Postdoctoral Science Foundation(2023TQ0300,and 2023M743171)the Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(GZB20230666)College Student Innovation and Entrepreneurship Training Program of Zhengzhou University(202410459200)。
文摘Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityhinders further applications.Conversely,all-inorganic perovskites possessexcellent thermal stability,but black-phase all-inorganic perovskite filmusually requires high-temperature annealing steps,which increases energy consumptionand is not conducive to the fabrication of flexible wearable devices.In this work,an unprecedented low-temperature fabrication of stable blackphaseCsPbI3perovskite films is demonstrated by the in situ hydrolysis reactionof diphenylphosphinic chloride additive.The released diphenyl phosphateand chloride ions during the hydrolysis reaction significantly lower the phasetransition temperature and effectively passivate the defects in the perovskitefilms,yielding high-performance photodetectors with a responsivity of 42.1 AW−1 and a detectivity of 1.3×10^(14)Jones.Furthermore,high-fidelity imageand photoplethysmography sensors are demonstrated based on the fabricated flexible wearable photodetectors.This work provides a newperspective for the low-temperature fabrication of large-area all-inorganic perovskite flexible optoelectronic devices.
基金supported by the National Natural Science Foundation of China(No.61704154)the Natural Science Foundation of Zhejiang Province(No.LY20F040006)the Open Foundation of the State Key Laboratory of Fluid Power and Mecha-tronic Systems(No.GZKF-202313).
文摘All-inorganic lead-free Cs_(2)AgBiBr_(6) double perovskite is a promising semiconductor for photodetection in daily life due to its outstanding photoelectrical properties,non-toxicity,and high stability.Compared with its organic-inorganic hybrid analogs,the fabrication method for Cs_(2)AgBiBr_(6) is not well developed.Solution-processed Cs_(2)AgBiBr_(6) films usually exhibit loosened morphology with small grains,many pin-holes,and abundant nonradiative defects.In particular,the disordered arrangements of Ag/Bi cations are thermodynamically favorable in Cs_(2)AgBiBr_(6),which contribute to the formation of self-trapped excitons and heavily restrict charge transport.Here in this work,a modified green antisolvent engineering strat-egy with phenethyl-ammonium bromide(PEABr)dissolved isopropyl alcohol(IPA)solution is developed to prepare high-quality Cs_(2)AgBiBr_(6) films.The PEABr/IPA treatment results in compact morphology with enlarged grains and promotes the ordered arrangements of Ag/Bi cations with improved charge transport.Through optimization,the target self-powered photodetector exhibits a responsivity of 0.38 AW−1,a spe-cific detectivity of 1.9×10^(12) Jones,a response time of 54/63μs,and a linear dynamic range of 107 dB,which is among the best-performing self-powered photodetectors based on lead-free perovskites.Our work thus provides a facile and green fabrication method for high-performance optoelectronic devices based on eco-friendly Cs_(2)AgBiBr_(6).
基金Supported by National Key Research and Development Program of China(2022YFA1404201)National Natural Science Foundation of China(62205187,U23A20380,U22A2091,62222509,62127817,62075120)+3 种基金Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(IRT_17R70)Fundamental Research Program of Shanxi Province(202103021223032,202303021222031)Project Funded by China Postdoctoral Science Foundation(2022M722006)Fund for Shanxi“1331 Project”Key Subjects Construction。
文摘Tin-lead(Sn-Pb)mixed perovskites are extensively investigated in near-infrared(NIR)photodetectors(PDs)owing to their excellent photoelectric performance.However,achieving high-performance Sn-Pb mixed PDs remains challenging,primarily because of the rapid crystallization and the susceptibility of Sn^(2+) to oxidation.To ad⁃dress these issues,this study introduces the multifunctional molecules 2,3-difluorobenzenamine(DBM)to modulate the crystallization of Sn-Pb mixed perovskites and retard the oxidation of Sn^(2+),thereby significantly enhancing film quality.Compared with the pristine film,Sn-Pb mixed perovskite films modulated by DBM molecules exhibit a high⁃ly homogeneous morphology,reduced roughness and defect density.The self-powered NIR PDs fabricated with the improved films have a spectral response range from 300 nm to 1100 nm,a peak responsivity of 0.51 A·W^(-1),a spe⁃cific detectivity as high as 2.46×10^(11)Jones within the NIR region(780 nm to 1100 nm),a linear dynamic range ex⁃ceeding 152 dB,and ultrafast rise/fall time of 123/464 ns.Thanks to the outstanding performance of PDs,the fabri⁃cated 5×5 PDs array demonstrates superior imaging ability in the NIR region up to 980 nm.This work advances the development of Sn-Pb mixed perovskites for NIR detection and paves the way for their commercialization.
基金Supported by National Key Research and Development Program in the 14th five year plan(2021YFA1200700)Strategic Priority Re⁃search Program of the Chinese Academy of Sciences(XDB0580000)Natural Science Foundation of China(62025405,62104235,62105348).
文摘Colloidal quantum dots(CQDs)are affected by the quantum confinement effect,which makes their bandgap tunable.This characteristic allows these materials to cover a broader infrared spectrum,providing a costeffective alternative to traditional infrared detector technology.Recently,thanks to the solution processing properties of quantum dots and their ability to integrate with silicon-based readout circuits on a single chip,infrared detectors based on HgTe CQDs have shown great application prospects.However,facing the challenges of vertically stacked photovoltaic devices,such as barrier layer matching and film non-uniformity,most devices integrated with readout circuits still use a planar structure,which limits the efficiency of light absorption and the effective separation and collection of photo-generated carriers.Here,by synthesizing high-quality HgTe CQDs and precisely controlling the interface quality,we have successfully fabricated a photovoltaic detector based on HgTe and ZnO QDs.At a working temperature of 80 K,this detector achieved a low dark current of 5.23×10^(-9)A cm^(-2),a high rectification ratio,and satisfactory detection sensitivity.This work paves a new way for the vertical integration of HgTe CQDs on silicon-based readout circuits,demonstrating their great potential in the field of high-performance infrared detection.
基金Supported by the National Key Research and Development Program of China(2021YFB2012601)National Natural Science Foundation of China(12204109)+1 种基金Science and Technology Innovation Plan of Shanghai Science and Technology Commission(21JC1400200)Higher Education Indus⁃try Support Program of Gansu Province(2022CYZC-06)。
文摘Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application of the organic semiconductor Y6-1O single crystal in photodetection devices.Firstly,Y6-1O single crystal material was prepared on a silicon substrate using solution droplet casting method.The optical properties of Y6-1O material were characterized by polarized optical microscopy,fluorescence spectroscopy,etc.,confirming its highly single crystalline performance and emission properties in the near-infrared region.Phototransistors based on Y6-1O materials with different thicknesses were then fabricated and tested.It was found that the devices exhibited good visible to near-infrared photoresponse,with the maximum photoresponse in the near-infrared region at 785 nm.The photocurrent on/off ratio reaches 10^(2),and photoresponsivity reaches 16 mA/W.It was also found that the spectral response of the device could be regulated by gate voltage as well as the material thickness,providing important conditions for optimizing the performance of near-infrared photodetectors.This study not only demonstrates the excellent performance of organic phototransistors based on Y6-1O single crystal material in near-infrared detection but also provides new ideas and directions for the future development of infrared detectors.
文摘All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have attracted extensive attention in photoelectric detection for their excellent photoelectric properties and stability.However,the CsPbBr_(3) quantum dot film exhibits a high non-radiative recombination rate,and the mismatch in energy levels with the carbon electrode weakens hole extraction efficiency.These reduces the device's performance.To improve this,a semiconductor photodetector based on fluorine-doped tin oxide(FTO)/dense titanium dioxide(c-TiO_(2))/mesoporous titanium dioxide(m-TiO_(2))/CsPbBr_(3) QDs/CsPbBr_(x)I_(3-x)(x=2,1.5,1)QDs/C struc-ture was studied.By adjusting the Br-:I-ratio,the synthesized CsPbBr_(x)I_(3-x)(x=2,1.5,1)QDs showed an adjustable band gap width of 2.284-2.394 eV.And forming a typeⅡband structure with CsPbBr_(3) QDs,which reduced the valence band offset between the active layer and the carbon electrode,this promoted carrier extraction and reduced non-radiative recombination rate.Compared with the original device(the photosensitive layer is CsPbBr_(3) QDs),the performance of the photodetector based on the CsPbBr_(3) QDs/CsPbBr2I QDs heterostructure is significantly improved,the responsivity(R)increased by 73%,the specific detectivity rate(D^(*))increased from 6.98×10^(12) to 3.19×10^(13) Jones,the on/off ratio reached 106.This study provides a new idea for the development of semiconductor tandem detectors.
