Two-dimensional perovskite ferroelectric which strongly couple ferroelectricity with semiconducting properties are promising candidates for optoelectronic applications.However,it is still a great challenge to fabricat...Two-dimensional perovskite ferroelectric which strongly couple ferroelectricity with semiconducting properties are promising candidates for optoelectronic applications.However,it is still a great challenge to fabricate self-powered broadband photodetectors with low detection limit.Herein,we successfully realized self-powered broadband photodetection with low detection limit by using a trilayered perovskite ferroelectric(BA)_(2)EA_(2)Pb_(3)I_(10)(1,BA=n-butylamine,EA=ethylamine).Giving to its large spontaneous polarization(5.6μC/cm^(2)),1 exhibits an open-circuit voltage of 0.25 V which provide driving force to separate carriers.Combining with its low dark current(~10^(-14)A)and narrow bandgap(Eg=1.86 e V),1 demonstrates great potential on detecting the broadband weak lights.Thus,a prominent photodetection performance with high open-off ratio(~10^(5)),outstanding responsivity(>10 m A/W),and promising detectivity(>1011Jones),as well as the low detecting limit(~nW/cm^(2))among the wide wavelength from 377 nm to637 nm was realized based on the single crystal of 1.This work demonstrates the great potential of 2D perovskite ferroelectric on self-powered broadband photodetectors.展开更多
Zero-dimensional(0D)metal halide perovskites with localized exciton environments have emerged as a new generation of high-efficiency luminescent materials.Introducing dopants into these luminescent materials have beco...Zero-dimensional(0D)metal halide perovskites with localized exciton environments have emerged as a new generation of high-efficiency luminescent materials.Introducing dopants into these luminescent materials have become a versatile way to tune photoluminescence for various optical application.Here,we report the synthesis of trivalent antimony(Sb^(3+))doped Cs_(3)CdBr_(5)with 0D structure using the solvothermal method.Theoretical calculations indicate that the undoped Cs_(3)CdBr_(5)perovskite has no emission due to the parity-forbidden transitions,whereas Sb^(3+)-doped Cs_(3)CdBr_(5)exhibits no forbidden transitions.Experimentally,Sb^(3+)doping significantly enhances the emission quantum yield from 0%to an impressive 94.14%.The intrinsic photophysical mechanism of the host-vip system is further elucidated by temperature-dependent photoluminescence spectra.With its excellent luminescence performance and temperature-dependent photoluminescence characteristics,Sb^(3+)-doped Cs_(3)CdBr_(5)shows potential for applications in lighting,encryption,and anti-counterfeiting.This work highlights the impact of Sb^(3+)ion doping on the optical properties of 0D metal halide perovskites Cs_(3)CdBr_(5),enabling multi-functional applications through their enhanced luminescence properties.展开更多
Cd-based Cs_(7)Cd_(3)Br_(13)perovskites,featuring both tetrahedral and octahedral polyhedral structures,have garnered significant acclaim for their efficient luminescent performance achieved through multi-exciton stat...Cd-based Cs_(7)Cd_(3)Br_(13)perovskites,featuring both tetrahedral and octahedral polyhedral structures,have garnered significant acclaim for their efficient luminescent performance achieved through multi-exciton state regulation by doping.However,it remains controversial whether the doping sites are in the octahedra or tetrahedra of Cs_(7)Cd_(3)Br_(13).To address this,we introduced Pb^(2+)and Sb^(3+)ions and,supported by experimental and theoretical evidence,demonstrated that these ions preferentially occupy the octahedra.Among them,Pb^(2+)ions single doping achieves a near-unity photoluminescence quantum yield of 93.7%,which results in excellent X-ray scintillation performance,high light yield of 41,772 photon MeV^(-1),and a low detection limit of 29.78 nGyairs-1.Moreover,this incorporation of Pb^(2+)and Sb^(3+)enabled an exciton state regulation strategy,resulting in standard white light emission with CIE chromaticity coordinates of(0.33,0.33).Additionally,a multifaceted optical anticounterfeiting and information encryption scheme was designed based on the differences in optical properties caused by the different sensitivities of[PbBr6]4-octahedron and[SbBr6]3-octahedron to temperature and excitation wavelengths.These diverse photoluminescence characteristics provide new insights and practical demonstrations for advanced X-ray imaging,lighting,optical encryption,and anticounterfeiting technologies.展开更多
To switch quadratic nonlinear optical（NLO） effects has become an exciting branch of the NLO material science. However, solid-state molecular crystals showing tunable and switchable NLO behaviors remain scarce. Here,...To switch quadratic nonlinear optical（NLO） effects has become an exciting branch of the NLO material science. However, solid-state molecular crystals showing tunable and switchable NLO behaviors remain scarce. Here, we report an organic picrate-based binary molecular crystal, triethylammonium picrate（TEAP）, which undergoes an above-room-temperature phase transition at T_c=319 K, being solidly confirmed by the thermal and dielectric measurements. A large thermal hysteresis of ~7 K discloses the first-order feature for its phase transition. More strikingly, the quadratic NLO effects of TEAP can be switched in the vicinity of Tc. That is, TEAP exhibits NLO-active response of ~1.5 times as large as that of KDP below T_c（i.e., NLO-on state）, while its NLO effects totally disappear above T_c（NLO-off state）. Structure analyses disclose that the order-disorder transformations of triethylammonium cations and picrate anions collectively contribute to its phase transition, as well as switchable NLO behaviors. This work opens up a new pathway to the designing and assembling of stimuli-responsive materials.展开更多
Polarized-light photodetectors are the indispensable elements for practical optical and optoelectronic device applications.Two-dimensional(2D)hybrid perovskite ferroelectrics,in which the coupling of spontaneous polar...Polarized-light photodetectors are the indispensable elements for practical optical and optoelectronic device applications.Two-dimensional(2D)hybrid perovskite ferroelectrics,in which the coupling of spontaneous polarization(P_(s))and light favors the dissociation of photo-induced carriers,have taken a booming position within this portfolio.However,polarized-light photodetectors with a low detectionlimit remain unexplored in this 2D ferroelectric family.In this work,the high-quality individual crystals of a 2D perovskite ferroelectric,BA_(2)CsPb_(2)Br_(7)(1,where BA^(+)is n-butylammonium),were used to fabricate ultrasensitive polarized-light detectors.Its unique bilayered structural motif results in quite strong electric and optical anisotropy with a large absorption ratio of a_(c)/α_(a)≈3.2(λ=405 nm).Besides,the presence of ferroelectric Psalso endows high built-in electric field along the polar c-axis that favors photoelectric activities.Under an extremely low detectable limit of 40 n W/cm^(2),the detector of 1 exhibits a notable dichroism ratio(I_(ph)^(c)/I_(ph)^(a)≈1.5),a large responsivity of~39.5 m A/W and a specific detectivity of~1.2×10^(12)Jones.Moreover,crystal-based devices of 1 also exhibit a fast response speed(~300μs)and excellent anti-fatigue merits.This work highlights great potentials of hybrid perovskite ferroelectrics toward polarized-light photodetection.展开更多
Two-dimensional(2D)hybrid perovskites with the Ruddlesden-Popper lattice(A')_(2)(A)_(n-1)M_(n)X_(3n+1)are emerging as the promising optoelectronic candidates,both the inorganic and organic ingredients of which can...Two-dimensional(2D)hybrid perovskites with the Ruddlesden-Popper lattice(A')_(2)(A)_(n-1)M_(n)X_(3n+1)are emerging as the promising optoelectronic candidates,both the inorganic and organic ingredients of which can be tailored to modulate the physical properties.Nevertheless,there is a scarcity of 2D multilayered motifs with the A-site large-size cations occupying perovskite cavities.Here,by rational mixedcation alloying,we present a new 2D hybrid perovskite,(4-TFBMA)_(2)(DMA)Pb_(2)I_(7)(1),in which the secondary cation of CH_(3)NH_(2)CH_(3)^(+)(DMA)is located inside the perovskite cage while the aromatic 4-(trifluoromethyl)benzylammonium(4-TFBMA)cation acts as a spacer moiety.Benefiting from the quantum structure of alternating organic spacers and inorganic networks,crystal-array detectors of 1 show fascinating in-plane photodetection responses of large detectivity(~2.95×10^(12)Jones)and responsivity(~1.97AW^(-1)),comparable to those of some inorganic 2D counterparts.In addition,a fast response rate(~264μs)and a low dark current are also realized,related to the high crystalline quality and suppression of the hopping barrier due to the insulating organic spacing layers.This result sheds light on the further exploration of new 2D hybrid perovskites toward high-performance photodetector applications.展开更多
Soft molecule-based ferroelectrics with unique structural flexibility hold apromise for versatile applications of non-volatile memory, imaging and photovoltaicdevices. Except for few polymers (e.g., polyvinylidene flu...Soft molecule-based ferroelectrics with unique structural flexibility hold apromise for versatile applications of non-volatile memory, imaging and photovoltaicdevices. Except for few polymers (e.g., polyvinylidene fluoride, PVDF),it is challenging to exploit soft ferroelectric crystals toward free-standing flexiblephotoactive devices. We here report a multiaxial soft molecule-based ferroelectric,(n-PA)_(2)PbCl_(4) (1, where n-PA^(+)is n-pentylammonium), of whichspontaneous polarization can be reversibly switched in both crystal and powderforms. Strikingly, single crystals of 1 have unusual structural flexibility andbendability, achieving the self-standing bending with a bending radius of0.22 mm. Besides, the pyroelectric activities are also preserved for these singlecrystals after several bending cycles. Further, the bendable crystal-basedphotodetector of 1 allows broadband photoactivities via the photo-pyroelectriceffect, covering a wide range from 405 to 940 nm spectral region, breakingthrough the limit of optical absorption bandgap. As the first study of bendablefree-standing photo-pyroelectric detectors in ferroelectric crystals, our worksheds light on the assembly of flexible smart photoelectric devices.展开更多
Ferroelectric materials have become key components for versatile device applications,and their thin films are highly desirable for integrating the miniaturized devices.Despite substantial endeavors,it is still challen...Ferroelectric materials have become key components for versatile device applications,and their thin films are highly desirable for integrating the miniaturized devices.Despite substantial endeavors,it is still challenging to achieve effective chemiresistive sensing in the ferroelectric films.Here,for the first time,we have exploited ferroelectric thin films of 2D hybrid perovskite BA_(2)EA_(2)Pb_(3)I_(10)(1),to fabricate the high-performance chemiresistor gas sensors.The spin-coated films of 1 exhibit high orientation and good crystallinity,thus preserving robust in-plane spontaneous polarization(P_(s)~2.0μC/cm^(2))and low electric coercivity.Notably,such ferroelectric filmbased sensors after electric poling enable the dramatic room-temperature sensing responses to NO_(2) gas,including high sensitivity(0.05 ppm^(-1)),extremely low detection limit(1 ppm)and fast responding rate(~6 s).Besides,the chemiresistive responses are remarkably enhanced by threefold(up to 320%)through electric poling.It is proposed that this behavior closely involves with strong in-plane ferroelectric polarization of 1 that generates a built-in electric field inhibiting the recombination of charge carriers.As far as we know,this ferroelectric-based film chemiresisor is one of the best room-temperature sensors for NO_(2) gas among all the existing candidate materials.These findings highlight great potential of ferroelectrics toward effective chemiresistive performances,and also establish a bright direction to explore their future device applications.展开更多
Organic-inorganic hybrids have shown great potential for assembling dielectric phase transition materials,due to their unique characteristics and structural diversities.Here,we construct a new organic-organic hybrid,(...Organic-inorganic hybrids have shown great potential for assembling dielectric phase transition materials,due to their unique characteristics and structural diversities.Here,we construct a new organic-organic hybrid,(cyclopropylaminium)_(3)BiBr_(6)(1),which consists of a zero-dimensional inorganic framework of BiBr_(6)octahedra and ternary cyclic organic cations.展开更多
Solid–solid phase transition materials have attracted increasing attention because of their variety of applications in optoelectronic devices,data storage,and ferroelectric field-effect transistors.Hybrid organic–in...Solid–solid phase transition materials have attracted increasing attention because of their variety of applications in optoelectronic devices,data storage,and ferroelectric field-effect transistors.Hybrid organic–inorganic perovskite materials combine the characteristics of organic and inorganic components and thus might be promising candidates to obtain phase-transition materials.Here,we report a lead-free organic–inorganic hybrid(hexamethyleneimine)2BiBr_(5)(1),which displays successive phase transitions at 268 K,304 K and 311 K upon heating;these phase transitions are induced by the distorted configurational change in organic cations and slight reorientational displacement of[BiBr_(5)]^(n)^(2−)polyanionic zigzag chains.In addition,the UV/Vis optical spectrum indicates that 1 has an indirect bandgap of 2.70 eV.Furthermore,computational analyses disclose that the inorganic perovskite-like building blocks of 1 contribute significantly to its semiconducting properties.This study offers a pathway to explore new lead-free organic–inorganic hybrids with phase transition.展开更多
Organic-inorganic hybrid perovskites(most notably CH_(3)NH_(3)PbI_(3))have recently been demonstrated as high-performance and low cost hybrid materials for photovoltaic application because of their prominent light-abs...Organic-inorganic hybrid perovskites(most notably CH_(3)NH_(3)PbI_(3))have recently been demonstrated as high-performance and low cost hybrid materials for photovoltaic application because of their prominent light-absorbing capacity and excellent optoelectronic properties.However,some serious concerns,including the potential toxicity of lead and chemical/phase instability of such hybrid perovskites,have become bottlenecks for their commercialization.In this study,through utilizing an alternative trivalent cation Sb^(3+)with the ns^(2)np^(0)electronic configuration,we designed a new lead-free hybrid material,[tert-butylammonium]_(4)[Sb_(4)I_(16)]·2H_(2)O(1),which adopts a zero-dimensional architecture consisting of corner-sharing SbI_(6)octahedra.It is noteworthy that 1 shows evident light-absorbance with a narrow optical bandgap of∼2.06 eV,along with positive temperature-dependent conductivity and notable photoconductive response.Moreover,1 displays phase stability under ambient conditions,which is superior to that of CH_(3)NH_(3)PbI_(3).The obtained results suggest the potential of 1 as a light absorbing material for photovoltaic applications.展开更多
Inspired by the breakthrough of three-dimensional hybrid perovskite CH_(3)NH_(3)PbI_(3),two-dimensional(2D)layered organic-inorganic halide perovskites are emerging as another promising class of hybrid materials for o...Inspired by the breakthrough of three-dimensional hybrid perovskite CH_(3)NH_(3)PbI_(3),two-dimensional(2D)layered organic-inorganic halide perovskites are emerging as another promising class of hybrid materials for optoelectronic devices,such as photodetectors fabricated on lead halide perovskites.However,the majority of such 2D materials exhibit photosensitivity to visible light,while few candidates have been reported to exhibit visible-blind ultraviolet(UV)photoelectric response.Here,we present a new hybrid material,(1,4-butyldiammonium)CdBr_(4)(1),in which the corner-sharing CdBr_(6)octahedra construct the 2D perovskite-type inorganic frameworks.The optical bandgap(Eg)of 1 is estimated to be~3.45 eV.Particularly,1 shows spectral-selective photoconductivity,that is,it is sensitive to UV-light illumination below 360 nm but almost blind to the standard visible light(above 400 nm),disclosing the potential of 1 for visible-blind ultraviolet photodetection.Further theoretical analyses of its electronic structure and energy gap disclose that the inorganic perovskite architecture dominates the optical bandgap.It is believed that this work provides a potential route for the design and fabrication of new 2D hybrid perovskite materials with a UV photoelectric response.展开更多
Two-dimensional(2D)multilayered hybrid perovskites adopting intrinsic quantum-well structures have shown great application potential in the field of optoelectronics.Despite extensive studies,candidate perovskites comp...Two-dimensional(2D)multilayered hybrid perovskites adopting intrinsic quantum-well structures have shown great application potential in the field of optoelectronics.Despite extensive studies,candidate perovskites composed of cage-templated secondary ammonium cations are quite scarce,hindering their application in high efficiency devices.Here,a new 2D hybrid perovskite(IA)2(DMA)Pb_(2)Br_(7)(1,IA^(+)=isoamylammonium and DMA^(+)=dimethylammonium)was synthesised,in which the inorganic bilayered frameworks are templated by secondary organic DMA^(+)cations in the perovskite cavities.This structural characteristic is distinct from the homologues containing monovalent cations.An alternative array of organic spacing bilayers and inorganic perovskite sheets forms its quantum-well motif,which leads to intriguing physical properties.Consequently,the fabricated crystal-based array detector exhibits highly efficient photodetection behaviors,including a low dark current(∼20 pA),large responsivity(∼110 mA W-1)and high detectivity(∼2.8×10^(11) Jones).These merits are related to the in-plane photoactivity of the perovskite sheets and low dark current of the insulated organic spacing bilayers.Besides,our photodetector also enables a response to polarized light with a dichromatic ratio of∼1.15.These findings pave the way to design new photoactive hybrid perovskites and reveal their potential for application in high-performance optoelectronic devices.展开更多
Organic-inorganic hybrid perovskites,most remarkably CH_(3)NH_(3)PbI_(3),have drawn a worldwide range of attention due to their great potential in optoelectronic and photovoltaic applications.Nevertheless,the concern ...Organic-inorganic hybrid perovskites,most remarkably CH_(3)NH_(3)PbI_(3),have drawn a worldwide range of attention due to their great potential in optoelectronic and photovoltaic applications.Nevertheless,the concern on the toxicity of the lead(Pb)element in chemical composition deserves to be addressed before it is further commercialized.In the present study,a new lead-free hybrid perovskite-like com pound,namely(C_(5)H_(11)N_(3))SbI_(5)(1,where C_(5)H_(11)N_(3)^(2+)is histaminium),has been synthesized and belongs to the chiral space group,P2_(1)2_(1)2_(1).Structurally,1 features a distinct perovskite-type architecture of one dimensional(1D)zigzag chains formed by the corner-sharing SbI6 octahedra with organic histaminium cations linked to the 1D chain framework via strong N–H⋯I hydrogen bonds.It is noteworthy to mention that 1 enables a wide absorption cutoffat 693 nm,corresponding to the narrow optical bandgap(Eg)of∼1.79 eV.Consequently,the distinct semiconducting behaviors and notable photoresponses in the visible-light range have been observed in 1,of which the photocurrent on/offratio reaches up to∼100 under light illumination at 650 nm.Density functional theory calculation reveals that the 1D zigzag chains formed by inorganic SbI6 octahedra determine its electronic structure and photoelectric activities.In addition to the excellent repeatability of photo-induced currents,1 also demonstrates superior phase stability and thermal stability.We believe that this study throws light on the further exploration of new lead-free hybrid perovskites for optoelectronic applications.展开更多
White-light emission in lead halide hybrid perovskites has attracted increasing attention due to their significant applications in the field of light-emitting devices.Despite tremendous efforts,two-dimensional (2D) wh...White-light emission in lead halide hybrid perovskites has attracted increasing attention due to their significant applications in the field of light-emitting devices.Despite tremendous efforts,two-dimensional (2D) white-light emissive perovskites with high photoluminescence quantum efficiency (PLQE) remain scarce.In this work,by using alkoxyamine organic cations as a template,we successfully synthesized a new 2D layered hybrid perovskite,(γ-methoxy propyl amine)2PbBr4 (γ-MPAPB),which exhibits bright bluish white-light emission with an excellent color rendering index (CRI) of 85 and a high PLQE of 6.85%.Photoluminescence measurements show a correlation between self-trapped excitons and white-light emission.To the best of our knowledge,this is the first demonstration of a 2D hybrid perovskite with efficient white-light emission based on alkoxyamine cations.This work emphasizes the strategy of introducing alkoxyamine cations into 2D layered hybrid perovskites to design efficient white-light emissive perovskite semiconductors.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22435005,22193042,21921001,22305105,52202194,22201284)Natural Science Foundation of Jiangxi Province(No.20224BAB213003)+1 种基金the Natural Science Foundation of Fujian Province(No.2023J05076)Jiangxi Provincial Education Department Science and Technology Research Foundation(No.GJJ2200384)。
文摘Two-dimensional perovskite ferroelectric which strongly couple ferroelectricity with semiconducting properties are promising candidates for optoelectronic applications.However,it is still a great challenge to fabricate self-powered broadband photodetectors with low detection limit.Herein,we successfully realized self-powered broadband photodetection with low detection limit by using a trilayered perovskite ferroelectric(BA)_(2)EA_(2)Pb_(3)I_(10)(1,BA=n-butylamine,EA=ethylamine).Giving to its large spontaneous polarization(5.6μC/cm^(2)),1 exhibits an open-circuit voltage of 0.25 V which provide driving force to separate carriers.Combining with its low dark current(~10^(-14)A)and narrow bandgap(Eg=1.86 e V),1 demonstrates great potential on detecting the broadband weak lights.Thus,a prominent photodetection performance with high open-off ratio(~10^(5)),outstanding responsivity(>10 m A/W),and promising detectivity(>1011Jones),as well as the low detecting limit(~nW/cm^(2))among the wide wavelength from 377 nm to637 nm was realized based on the single crystal of 1.This work demonstrates the great potential of 2D perovskite ferroelectric on self-powered broadband photodetectors.
基金financially supported by the National Natural Science Foundation of China(Nos.62374104,62374103,22205233)the Jinan Central Hospital Collaboration(No.1190022050)+3 种基金the Taishan Scholar Foundation of Shandong Province(No.tsqn2023120051105)the Basic and Applied Basic Research Foundation of Guangdong Province(No.2024A1515010926)the China Postdoctoral Science Foundation(No.2024M751789)the Postdoctoral Innovation Projects of Shandong Province(No.202400321).
文摘Zero-dimensional(0D)metal halide perovskites with localized exciton environments have emerged as a new generation of high-efficiency luminescent materials.Introducing dopants into these luminescent materials have become a versatile way to tune photoluminescence for various optical application.Here,we report the synthesis of trivalent antimony(Sb^(3+))doped Cs_(3)CdBr_(5)with 0D structure using the solvothermal method.Theoretical calculations indicate that the undoped Cs_(3)CdBr_(5)perovskite has no emission due to the parity-forbidden transitions,whereas Sb^(3+)-doped Cs_(3)CdBr_(5)exhibits no forbidden transitions.Experimentally,Sb^(3+)doping significantly enhances the emission quantum yield from 0%to an impressive 94.14%.The intrinsic photophysical mechanism of the host-vip system is further elucidated by temperature-dependent photoluminescence spectra.With its excellent luminescence performance and temperature-dependent photoluminescence characteristics,Sb^(3+)-doped Cs_(3)CdBr_(5)shows potential for applications in lighting,encryption,and anti-counterfeiting.This work highlights the impact of Sb^(3+)ion doping on the optical properties of 0D metal halide perovskites Cs_(3)CdBr_(5),enabling multi-functional applications through their enhanced luminescence properties.
基金funded by the Jinan Central Hospital Collaboration(1190022050)Foundation for Innovative Research Groups of the National Natural Science Foundation of China(22205233,62374103,62374104,and 62405165)+3 种基金Basic and Applied Basic Research Foundation of Guangdong Province(2024A1515010926)Taishan Scholar Foundation of Shandong Province of Shandong Province(tsqn202312005)Postdoctoral Innovative Projects of Shandong Province(202400321)China Postdoctoral Science Foundation(2024M751789)。
文摘Cd-based Cs_(7)Cd_(3)Br_(13)perovskites,featuring both tetrahedral and octahedral polyhedral structures,have garnered significant acclaim for their efficient luminescent performance achieved through multi-exciton state regulation by doping.However,it remains controversial whether the doping sites are in the octahedra or tetrahedra of Cs_(7)Cd_(3)Br_(13).To address this,we introduced Pb^(2+)and Sb^(3+)ions and,supported by experimental and theoretical evidence,demonstrated that these ions preferentially occupy the octahedra.Among them,Pb^(2+)ions single doping achieves a near-unity photoluminescence quantum yield of 93.7%,which results in excellent X-ray scintillation performance,high light yield of 41,772 photon MeV^(-1),and a low detection limit of 29.78 nGyairs-1.Moreover,this incorporation of Pb^(2+)and Sb^(3+)enabled an exciton state regulation strategy,resulting in standard white light emission with CIE chromaticity coordinates of(0.33,0.33).Additionally,a multifaceted optical anticounterfeiting and information encryption scheme was designed based on the differences in optical properties caused by the different sensitivities of[PbBr6]4-octahedron and[SbBr6]3-octahedron to temperature and excitation wavelengths.These diverse photoluminescence characteristics provide new insights and practical demonstrations for advanced X-ray imaging,lighting,optical encryption,and anticounterfeiting technologies.
基金supported by the National Natural Science Foundation of China(Nos. 21622108, 21525104, 21601188, 91422301, 21373220, 51402296 and 51502290)the Natural Science Foundation of Fujian Province(No. 2015J05040)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(No. XDB20000000)the Youth Innovation Promotion of CAS(No. 2014262)the State Key Laboratory of Luminescence and Applications(No. SKLA-2016-09)
文摘To switch quadratic nonlinear optical（NLO） effects has become an exciting branch of the NLO material science. However, solid-state molecular crystals showing tunable and switchable NLO behaviors remain scarce. Here, we report an organic picrate-based binary molecular crystal, triethylammonium picrate（TEAP）, which undergoes an above-room-temperature phase transition at T_c=319 K, being solidly confirmed by the thermal and dielectric measurements. A large thermal hysteresis of ~7 K discloses the first-order feature for its phase transition. More strikingly, the quadratic NLO effects of TEAP can be switched in the vicinity of Tc. That is, TEAP exhibits NLO-active response of ~1.5 times as large as that of KDP below T_c（i.e., NLO-on state）, while its NLO effects totally disappear above T_c（NLO-off state）. Structure analyses disclose that the order-disorder transformations of triethylammonium cations and picrate anions collectively contribute to its phase transition, as well as switchable NLO behaviors. This work opens up a new pathway to the designing and assembling of stimuli-responsive materials.
基金supported by the National Natural Science Foundation of China(21622108,21875251,21525104,and 21833010)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20010200)Youth Innovation Promotion of Chinese Academy of Sciences。
文摘Polarized-light photodetectors are the indispensable elements for practical optical and optoelectronic device applications.Two-dimensional(2D)hybrid perovskite ferroelectrics,in which the coupling of spontaneous polarization(P_(s))and light favors the dissociation of photo-induced carriers,have taken a booming position within this portfolio.However,polarized-light photodetectors with a low detectionlimit remain unexplored in this 2D ferroelectric family.In this work,the high-quality individual crystals of a 2D perovskite ferroelectric,BA_(2)CsPb_(2)Br_(7)(1,where BA^(+)is n-butylammonium),were used to fabricate ultrasensitive polarized-light detectors.Its unique bilayered structural motif results in quite strong electric and optical anisotropy with a large absorption ratio of a_(c)/α_(a)≈3.2(λ=405 nm).Besides,the presence of ferroelectric Psalso endows high built-in electric field along the polar c-axis that favors photoelectric activities.Under an extremely low detectable limit of 40 n W/cm^(2),the detector of 1 exhibits a notable dichroism ratio(I_(ph)^(c)/I_(ph)^(a)≈1.5),a large responsivity of~39.5 m A/W and a specific detectivity of~1.2×10^(12)Jones.Moreover,crystal-based devices of 1 also exhibit a fast response speed(~300μs)and excellent anti-fatigue merits.This work highlights great potentials of hybrid perovskite ferroelectrics toward polarized-light photodetection.
基金supported by the National Natural Science Foundation of China(21875251,21833010,21525104,22075285 and 21921001)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-SLH024)+3 种基金Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZR126)the Natural Science Foundation of Fujian Province(2018H0047 and 2020J01112)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20010200)the Youth Innovation Promotion of the Chinese Academy of Sciences(2019301 and 2020307).
文摘Two-dimensional(2D)hybrid perovskites with the Ruddlesden-Popper lattice(A')_(2)(A)_(n-1)M_(n)X_(3n+1)are emerging as the promising optoelectronic candidates,both the inorganic and organic ingredients of which can be tailored to modulate the physical properties.Nevertheless,there is a scarcity of 2D multilayered motifs with the A-site large-size cations occupying perovskite cavities.Here,by rational mixedcation alloying,we present a new 2D hybrid perovskite,(4-TFBMA)_(2)(DMA)Pb_(2)I_(7)(1),in which the secondary cation of CH_(3)NH_(2)CH_(3)^(+)(DMA)is located inside the perovskite cage while the aromatic 4-(trifluoromethyl)benzylammonium(4-TFBMA)cation acts as a spacer moiety.Benefiting from the quantum structure of alternating organic spacers and inorganic networks,crystal-array detectors of 1 show fascinating in-plane photodetection responses of large detectivity(~2.95×10^(12)Jones)and responsivity(~1.97AW^(-1)),comparable to those of some inorganic 2D counterparts.In addition,a fast response rate(~264μs)and a low dark current are also realized,related to the high crystalline quality and suppression of the hopping barrier due to the insulating organic spacing layers.This result sheds light on the further exploration of new 2D hybrid perovskites toward high-performance photodetector applications.
基金National Natural Science Foundation of China,Grant/Award Numbers:22125110,U23A2094,22205233,22193042,21921001,U21A2069,22305248Natural Science Foundation of Fujian Province,Grant/Award Numbers:2023J02028,2023J01235+2 种基金Key Research Program of Frontier Sciences of Chinese Academy of Sciences,Grant/Award Number:ZDBSLY-SLH024Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China,Grant/Award Number:2021ZR126China Postdoctoral Science Foundation,Grant/Award Number:2023M733497。
文摘Soft molecule-based ferroelectrics with unique structural flexibility hold apromise for versatile applications of non-volatile memory, imaging and photovoltaicdevices. Except for few polymers (e.g., polyvinylidene fluoride, PVDF),it is challenging to exploit soft ferroelectric crystals toward free-standing flexiblephotoactive devices. We here report a multiaxial soft molecule-based ferroelectric,(n-PA)_(2)PbCl_(4) (1, where n-PA^(+)is n-pentylammonium), of whichspontaneous polarization can be reversibly switched in both crystal and powderforms. Strikingly, single crystals of 1 have unusual structural flexibility andbendability, achieving the self-standing bending with a bending radius of0.22 mm. Besides, the pyroelectric activities are also preserved for these singlecrystals after several bending cycles. Further, the bendable crystal-basedphotodetector of 1 allows broadband photoactivities via the photo-pyroelectriceffect, covering a wide range from 405 to 940 nm spectral region, breakingthrough the limit of optical absorption bandgap. As the first study of bendablefree-standing photo-pyroelectric detectors in ferroelectric crystals, our worksheds light on the assembly of flexible smart photoelectric devices.
基金supported by National Natural Science Foundation of China(22125110,21875251,21833010 and 21921001)the National Postdoctoral Program for Innovative Talents(BX2021315)+4 种基金the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-SLH024)Youth Innovation Promotion of CAS(Y201851)the National Natural Science Foundation of China(21975254,21822109)International Part-nership Program of CAS(121835KYSB201800)Youth Innovation Promotion of CAS(2018342).
文摘Ferroelectric materials have become key components for versatile device applications,and their thin films are highly desirable for integrating the miniaturized devices.Despite substantial endeavors,it is still challenging to achieve effective chemiresistive sensing in the ferroelectric films.Here,for the first time,we have exploited ferroelectric thin films of 2D hybrid perovskite BA_(2)EA_(2)Pb_(3)I_(10)(1),to fabricate the high-performance chemiresistor gas sensors.The spin-coated films of 1 exhibit high orientation and good crystallinity,thus preserving robust in-plane spontaneous polarization(P_(s)~2.0μC/cm^(2))and low electric coercivity.Notably,such ferroelectric filmbased sensors after electric poling enable the dramatic room-temperature sensing responses to NO_(2) gas,including high sensitivity(0.05 ppm^(-1)),extremely low detection limit(1 ppm)and fast responding rate(~6 s).Besides,the chemiresistive responses are remarkably enhanced by threefold(up to 320%)through electric poling.It is proposed that this behavior closely involves with strong in-plane ferroelectric polarization of 1 that generates a built-in electric field inhibiting the recombination of charge carriers.As far as we know,this ferroelectric-based film chemiresisor is one of the best room-temperature sensors for NO_(2) gas among all the existing candidate materials.These findings highlight great potential of ferroelectrics toward effective chemiresistive performances,and also establish a bright direction to explore their future device applications.
基金supported by the National Natural Science Foundation of China(21875251,21622108,21833010,21525104)the NSF of Fujian Province(2018H0047)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20010200).
文摘Organic-inorganic hybrids have shown great potential for assembling dielectric phase transition materials,due to their unique characteristics and structural diversities.Here,we construct a new organic-organic hybrid,(cyclopropylaminium)_(3)BiBr_(6)(1),which consists of a zero-dimensional inorganic framework of BiBr_(6)octahedra and ternary cyclic organic cations.
基金supported by the National Natural Science Foundation of China(21622108,21875251,21525104,21833010,21601188,51502290,and 51502288)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20010200).
文摘Solid–solid phase transition materials have attracted increasing attention because of their variety of applications in optoelectronic devices,data storage,and ferroelectric field-effect transistors.Hybrid organic–inorganic perovskite materials combine the characteristics of organic and inorganic components and thus might be promising candidates to obtain phase-transition materials.Here,we report a lead-free organic–inorganic hybrid(hexamethyleneimine)2BiBr_(5)(1),which displays successive phase transitions at 268 K,304 K and 311 K upon heating;these phase transitions are induced by the distorted configurational change in organic cations and slight reorientational displacement of[BiBr_(5)]^(n)^(2−)polyanionic zigzag chains.In addition,the UV/Vis optical spectrum indicates that 1 has an indirect bandgap of 2.70 eV.Furthermore,computational analyses disclose that the inorganic perovskite-like building blocks of 1 contribute significantly to its semiconducting properties.This study offers a pathway to explore new lead-free organic–inorganic hybrids with phase transition.
基金NSFC(21622108,21875251,21525104,21601188,51502289,21571178)Strategic Priority Research Program of the CAS(XDB20000000)。
文摘Organic-inorganic hybrid perovskites(most notably CH_(3)NH_(3)PbI_(3))have recently been demonstrated as high-performance and low cost hybrid materials for photovoltaic application because of their prominent light-absorbing capacity and excellent optoelectronic properties.However,some serious concerns,including the potential toxicity of lead and chemical/phase instability of such hybrid perovskites,have become bottlenecks for their commercialization.In this study,through utilizing an alternative trivalent cation Sb^(3+)with the ns^(2)np^(0)electronic configuration,we designed a new lead-free hybrid material,[tert-butylammonium]_(4)[Sb_(4)I_(16)]·2H_(2)O(1),which adopts a zero-dimensional architecture consisting of corner-sharing SbI_(6)octahedra.It is noteworthy that 1 shows evident light-absorbance with a narrow optical bandgap of∼2.06 eV,along with positive temperature-dependent conductivity and notable photoconductive response.Moreover,1 displays phase stability under ambient conditions,which is superior to that of CH_(3)NH_(3)PbI_(3).The obtained results suggest the potential of 1 as a light absorbing material for photovoltaic applications.
基金supported by the NSFC(21525104,21833010,21622108,51502290,21601188)the NSF of Fujian Province(2015J05040)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)the Youth Innovation Promotion of CAS(2014262 and 2015240).
文摘Inspired by the breakthrough of three-dimensional hybrid perovskite CH_(3)NH_(3)PbI_(3),two-dimensional(2D)layered organic-inorganic halide perovskites are emerging as another promising class of hybrid materials for optoelectronic devices,such as photodetectors fabricated on lead halide perovskites.However,the majority of such 2D materials exhibit photosensitivity to visible light,while few candidates have been reported to exhibit visible-blind ultraviolet(UV)photoelectric response.Here,we present a new hybrid material,(1,4-butyldiammonium)CdBr_(4)(1),in which the corner-sharing CdBr_(6)octahedra construct the 2D perovskite-type inorganic frameworks.The optical bandgap(Eg)of 1 is estimated to be~3.45 eV.Particularly,1 shows spectral-selective photoconductivity,that is,it is sensitive to UV-light illumination below 360 nm but almost blind to the standard visible light(above 400 nm),disclosing the potential of 1 for visible-blind ultraviolet photodetection.Further theoretical analyses of its electronic structure and energy gap disclose that the inorganic perovskite architecture dominates the optical bandgap.It is believed that this work provides a potential route for the design and fabrication of new 2D hybrid perovskite materials with a UV photoelectric response.
基金supported by the NSFC(22125110,21875251,21833010,22075285,and 21921001)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-SLH024)+4 种基金the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZR126)the Strategic Priority Research Program of the CAS(XDB20010200)the National Postdoctoral Program for Innovative Talents(BX2021315)the Youth Innovation Promotion of CAS(Y201851)the National Postdoctoral Program for Innovative Talents(BX2021315).
文摘Two-dimensional(2D)multilayered hybrid perovskites adopting intrinsic quantum-well structures have shown great application potential in the field of optoelectronics.Despite extensive studies,candidate perovskites composed of cage-templated secondary ammonium cations are quite scarce,hindering their application in high efficiency devices.Here,a new 2D hybrid perovskite(IA)2(DMA)Pb_(2)Br_(7)(1,IA^(+)=isoamylammonium and DMA^(+)=dimethylammonium)was synthesised,in which the inorganic bilayered frameworks are templated by secondary organic DMA^(+)cations in the perovskite cavities.This structural characteristic is distinct from the homologues containing monovalent cations.An alternative array of organic spacing bilayers and inorganic perovskite sheets forms its quantum-well motif,which leads to intriguing physical properties.Consequently,the fabricated crystal-based array detector exhibits highly efficient photodetection behaviors,including a low dark current(∼20 pA),large responsivity(∼110 mA W-1)and high detectivity(∼2.8×10^(11) Jones).These merits are related to the in-plane photoactivity of the perovskite sheets and low dark current of the insulated organic spacing bilayers.Besides,our photodetector also enables a response to polarized light with a dichromatic ratio of∼1.15.These findings pave the way to design new photoactive hybrid perovskites and reveal their potential for application in high-performance optoelectronic devices.
基金supported by National Natural Science Foundation of China(21622108,21875251,21833010,and 21525104)the Natural Science Foundation of Fujian Province(2018H0047)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB20010200)the Youth Innovation Promotion of Chinese Academy of Sciences(2014262).
文摘Organic-inorganic hybrid perovskites,most remarkably CH_(3)NH_(3)PbI_(3),have drawn a worldwide range of attention due to their great potential in optoelectronic and photovoltaic applications.Nevertheless,the concern on the toxicity of the lead(Pb)element in chemical composition deserves to be addressed before it is further commercialized.In the present study,a new lead-free hybrid perovskite-like com pound,namely(C_(5)H_(11)N_(3))SbI_(5)(1,where C_(5)H_(11)N_(3)^(2+)is histaminium),has been synthesized and belongs to the chiral space group,P2_(1)2_(1)2_(1).Structurally,1 features a distinct perovskite-type architecture of one dimensional(1D)zigzag chains formed by the corner-sharing SbI6 octahedra with organic histaminium cations linked to the 1D chain framework via strong N–H⋯I hydrogen bonds.It is noteworthy to mention that 1 enables a wide absorption cutoffat 693 nm,corresponding to the narrow optical bandgap(Eg)of∼1.79 eV.Consequently,the distinct semiconducting behaviors and notable photoresponses in the visible-light range have been observed in 1,of which the photocurrent on/offratio reaches up to∼100 under light illumination at 650 nm.Density functional theory calculation reveals that the 1D zigzag chains formed by inorganic SbI6 octahedra determine its electronic structure and photoelectric activities.In addition to the excellent repeatability of photo-induced currents,1 also demonstrates superior phase stability and thermal stability.We believe that this study throws light on the further exploration of new lead-free hybrid perovskites for optoelectronic applications.
基金supported by the National Natural Science Foundation of China(21833010,21861014,21525104,21875251,21971238,21975258,61975207 and 21921001)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-SLH024)+1 种基金the NSF of Fujian Province(2018H0047),the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20010200)the Youth Innovation Promotion of CAS(2019301 and 2020307).
文摘White-light emission in lead halide hybrid perovskites has attracted increasing attention due to their significant applications in the field of light-emitting devices.Despite tremendous efforts,two-dimensional (2D) white-light emissive perovskites with high photoluminescence quantum efficiency (PLQE) remain scarce.In this work,by using alkoxyamine organic cations as a template,we successfully synthesized a new 2D layered hybrid perovskite,(γ-methoxy propyl amine)2PbBr4 (γ-MPAPB),which exhibits bright bluish white-light emission with an excellent color rendering index (CRI) of 85 and a high PLQE of 6.85%.Photoluminescence measurements show a correlation between self-trapped excitons and white-light emission.To the best of our knowledge,this is the first demonstration of a 2D hybrid perovskite with efficient white-light emission based on alkoxyamine cations.This work emphasizes the strategy of introducing alkoxyamine cations into 2D layered hybrid perovskites to design efficient white-light emissive perovskite semiconductors.
