Silver nanowires(Ag NWs)have promising application potential in electronic displays because of their superior flexibility and transparency.Doping Ni in Ag NWs has proven to be an effective strategy to im-prove its wor...Silver nanowires(Ag NWs)have promising application potential in electronic displays because of their superior flexibility and transparency.Doping Ni in Ag NWs has proven to be an effective strategy to im-prove its work function.However,AgNi NWs-based electrodes suffer from poor electrical conductivity under air exposure due to the low-conductivity NiO generated on its surface.Here,Cu was further doped in AgNi NWs to form AgNiCu NWs and regulate its surface oxide under long-term air exposure.Finally,it is demonstrated that the conductivity of AgNiCu NWs can acquire an improved tolerable tempera-ture(over 240℃)and prolonged high-temperature tolerance time(over 150 min)by finely regulating the doping content Cu,indicating an enhanced air-stable conductivity.The optimized AgNiCu NWs also achieve superior transparent conductivity as pure Ag NWs and high work function as AgNi NWs,which has been successfully applied in constructing an n-type photodiode with an effective rectification effect.展开更多
This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy s...This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy structure and coplanar waveguide electrodes,the fabricated 4-μm-diameter PD exhibits ultra-flat frequency response and high saturation power.Integrated passive circuits including low-loss bias-tee and E-plane probe are designed to package the PD into a compact module with waveguide output.The packaged PD module has demonstrated a flat frequency response with fluctuations within±2.75 d B over a broadband of 140–220 GHz and a high saturated output power of-7.8 d Bm(166μW)at 140 GHz.For wireless communication applications,the packaged PD is used to implement 1-m free space transmission at carrier frequencies of 150.5 and 210.5 GHz,with transmission rates of 75 and 90 Gbps,respectively.展开更多
The development of InGaAs/InP single-photon avalanche photodiodes(SPADs)necessitates the utiliza-tion of a two-element diffusion technique to achieve accurate manipulation of the multiplication width and the dis-tribu...The development of InGaAs/InP single-photon avalanche photodiodes(SPADs)necessitates the utiliza-tion of a two-element diffusion technique to achieve accurate manipulation of the multiplication width and the dis-tribution of its electric field.Regarding the issue of accurately predicting the depth of diffusion in InGaAs/InP SPAD,simulation analysis and device development were carried out,focusing on the dual diffusion behavior of zinc atoms.A formula of X_(j)=k√t-t_(0)+c to quantitatively predict the diffusion depth is obtained by fitting the simulated twice-diffusion depths based on a two-dimensional(2D)model.The 2D impurity morphologies and the one-dimensional impurity profiles for the dual-diffused region are characterized by using scanning electron micros-copy and secondary ion mass spectrometry as a function of the diffusion depth,respectively.InGaAs/InP SPAD devices with different dual-diffusion conditions are also fabricated,which show breakdown behaviors well consis-tent with the simulated results under the same junction geometries.The dark count rate(DCR)of the device de-creased as the multiplication width increased,as indicated by the results.DCRs of 2×10^(6),1×10^(5),4×10^(4),and 2×10^(4) were achieved at temperatures of 300 K,273 K,263 K,and 253 K,respectively,with a bias voltage of 3 V,when the multiplication width was 1.5µm.These results demonstrate an effective prediction route for accu-rately controlling the dual-diffused zinc junction geometry in InP-based planar device processing.展开更多
The influence of thermal treatment on Si 1-x Ge x/Si multiple-quantum wells (MQW) p-i-n photodiodes has been investigated by photocurrent spectroscopy combined with X-ray double crystal dif...The influence of thermal treatment on Si 1-x Ge x/Si multiple-quantum wells (MQW) p-i-n photodiodes has been investigated by photocurrent spectroscopy combined with X-ray double crystal diffraction.The cutoff wavelength is significantly reduced due to the Si-Ge interdiffusion and partial relaxation of the strained SiGe alloy.The values of the blue shift increase slowly with the annealing temperatures in the range of 750℃ to 850℃.However,the nonlinear changes in photocurrent intensities of the samples annealed at different temperatures have been observed,which is mainly dominated by the generation of misfit dislocations and the reduction of the point defects in the heating process.展开更多
A different approach,using the molecular beam epitaxy (MBE)-grown ZnS-based Schottky photodiode technology,is applied to fabricate an 8×8 photodiode array.The micro-processing procedures of this photodiode array ...A different approach,using the molecular beam epitaxy (MBE)-grown ZnS-based Schottky photodiode technology,is applied to fabricate an 8×8 photodiode array.The micro-processing procedures of this photodiode array including standard photolithography,a number of metallisation,wet-chemical etching and SiO_2 deposition for insulation are developed.The detector is characterized to have a cutoff wavelength at 340 nm and the photo-responsivity measurements on the pixels result an ultraviolet (UV) response as high as 0.15 A/W,corresponding to an external quantum efficiency of 55% in the visible-blind spectral ranging from 400 down to 250nm.Imaging tests indicate that this array is able to capture the intensity profile of a given UV light source with reasonably good capability.展开更多
The relationships between irradiation doses of γ ray and the main photoelectric characteristics of PIN photodiode or conventional photodiode with different structure were studied. The experimental results show that a...The relationships between irradiation doses of γ ray and the main photoelectric characteristics of PIN photodiode or conventional photodiode with different structure were studied. The experimental results show that after the photodiodes being irradiated,the photocurrent decreases,especially for short wavelength of light. The dark current of the photodiodes with smaller active area decreases while increases for that with larger active area,and the response time shortens. The plane scanning experiment of laser beam indicates that the homogeneity of the device's surface is not influenced by the irradiation. The results prove that PIN photodiode shows relatively good radioresistance.展开更多
A compact and stable three-port optical gate has been successfully fabricated by monolithically integrating a simple photodiode and an electroabsorption modulator. The gate shows an excellent DC logic ＂and＂ function...A compact and stable three-port optical gate has been successfully fabricated by monolithically integrating a simple photodiode and an electroabsorption modulator. The gate shows an excellent DC logic ＂and＂ function with different load resistors. Its dynamical characteristics without packaging have also been measured. We observed a dynamic extinction ratio of over 7dB with a 95012 load resistor and a 7mW control light power at 622Mbit/s.展开更多
4H-SiC single photon counting avalanche photodiodes(SPADs)are prior devices for weak ultraviolet(UV)signal detection with the advantages of small size,low leakage current,high avalanche multiplication gain,and high qu...4H-SiC single photon counting avalanche photodiodes(SPADs)are prior devices for weak ultraviolet(UV)signal detection with the advantages of small size,low leakage current,high avalanche multiplication gain,and high quantum efficiency,which benefit from the large bandgap energy,high carrier drift velocity and excellent physical stability of 4 H-SiC semiconductor material.UV detectors are widely used in many key applications,such as missile plume detection,corona discharge,UV astronomy,and biological and chemical agent detection.In this paper,we will describe basic concepts and review recent results on device design,process development,and basic characterizations of 4 H-SiC avalanche photodiodes.Several promising device structures and uniformity of avalanche multiplication are discussed,which are important for achieving high performance of 4 HSiC UV SPADs.展开更多
The effect of high-energy proton irradiation on GaN-based ultraviolet avalanche photodiodes(APDs) is investigated. The dark current of the GaN APD is calculated as a function of the proton energy and proton fluences. ...The effect of high-energy proton irradiation on GaN-based ultraviolet avalanche photodiodes(APDs) is investigated. The dark current of the GaN APD is calculated as a function of the proton energy and proton fluences. By considering the diffusion, generation–recombination, local hopping conductivity, band-to-band tunneling, and trap-assisted tunneling currents, we found that the dark current increases as the proton fluence increases, but decreases with increasing proton energy.展开更多
Quantum random number generators adopting single negligible dead time of avalanche photodiodes （APDs） photon detection have been restricted due to the non- We propose a new approach based on an APD array to improve...Quantum random number generators adopting single negligible dead time of avalanche photodiodes （APDs） photon detection have been restricted due to the non- We propose a new approach based on an APD array to improve the generation rate of random numbers significantly. This method compares the detectors＇ responses to consecutive optical pulses and generates the random sequence. We implement a demonstration experiment to show its simplicity, compactness and scalability. The generated numbers are proved to be unbiased, post-processing free, ready to use, and their randomness is verified by using the national institute of standard technology statistical test suite. The random bit generation efficiency is as high as 32.8% and the potential generation rate adopting the 32× 32 APD array is up to tens of Gbits/s.展开更多
Silicon photonics technology has drawn significant interest due to its potential for compact and high-performance photonic integrated circuits.The Ge-or III-V material-based avalanche photodiodes integrated on silicon...Silicon photonics technology has drawn significant interest due to its potential for compact and high-performance photonic integrated circuits.The Ge-or III-V material-based avalanche photodiodes integrated on silicon photonics provide ideal high sensitivity optical receivers for telecommunication wavelengths.Herein,the last advances of monolithic and hetero-geneous avalanche photodiodes on silicon are reviewed,including different device structures and semiconductor systems.展开更多
A two-dimensional(2D)organic-inorganic hybrid perovskite(OIHP)material is considered as a promising candidate for a long-term stable photodetector owing to its outstanding phase and environmental stability.Herein,we d...A two-dimensional(2D)organic-inorganic hybrid perovskite(OIHP)material is considered as a promising candidate for a long-term stable photodetector owing to its outstanding phase and environmental stability.Herein,we demonstrate a perovskite photodiode based on the DJ phase 2D perovskite(PDA)(MA)_(n-1)Pb_(n)I_(3n+1)(where PDA is 1,3-propylenediamine,MA is methylamine,nominal n=4).The best-performance device exhibits a high detectivity of 4.57×10^(11) Jones,a responsivity of 0.25 A·W^(-1) at 480 nm,a low dark current density of 9.60×10^(-4) mA cm^(-2),and a remarkable on/off ratio of 3.10×10^(5).The unencapsulated device can maintain 95%of the initial photocurrent density after 90 days under an ambient atmosphere with relative humidity(RH)of 65%,demonstrating its improved stability than the 3D counterpart.The excellent stability of the photodiode based on 2D perovskite promises its bright commercial application ftiture.展开更多
The effect of Al doping on the J-V characteristics sol-gel derived of ZnO/p-Si photodiodes was investigated.The resistivity of Si was 0.1Ω·cm.ZnO films annealed at 500℃ were of the best quality.To investigate t...The effect of Al doping on the J-V characteristics sol-gel derived of ZnO/p-Si photodiodes was investigated.The resistivity of Si was 0.1Ω·cm.ZnO films annealed at 500℃ were of the best quality.To investigate the spectral response of the photodiodes,the J-V characteristics were measured under different monochromatic lights at wavelength 420,530,570 and 630 nm.The diodes exhibit strong responsivity in the blue region at 420 nm.The responsivity is 0.22 A/W for Al doped （0.8 wt pct） photodiode,whereas for the undoped photodiode,it was much lower.An estimate of the responsivity as a function of wavelength has been made in terms of the width of depletion region of photodiodes.展开更多
A novel device, lateral PIN photodiode gated by transparent electrode （LPIN PD-GTE） fabricated on fully-depleted SOI film was proposed. ITO film was adopted in the device as gate electrode to reduce the light absorp...A novel device, lateral PIN photodiode gated by transparent electrode （LPIN PD-GTE） fabricated on fully-depleted SOI film was proposed. ITO film was adopted in the device as gate electrode to reduce the light absorption. Thin Si film was fully depleted under gate voltage to achieve low dark current and high photo4o-dark current ratio. The model of gate voltage was obtained and the numerical simulations were presented by ATLAS. Current-voltage characteristics of LPIN PD-GTE obtained in dark （dark current） and under 570 nm illumination （photo current） were studied to achieve the greatest photo-to-dark current ratio for active channel length from 2 to 12 /am. The results show that the photo-to-dark current ratio is 2.0×10^7, with dark current of around 5×10^-4 pA under VGK=0.6 V, PrN=5 mW/cm2, for a total area of 10μm×10μm in fully depleted SOI technology. Thus, the LPIN PD-GTE can be suitable for high-grade photoelectric systems such as blue DVD.展开更多
Experimental techniques based on SR facilities have emerged with the development of synchrotron radiation(SR)sources.Accordingly,detector miniaturization has become significant for the development of SR experimental t...Experimental techniques based on SR facilities have emerged with the development of synchrotron radiation(SR)sources.Accordingly,detector miniaturization has become significant for the development of SR experimental techniques.In this study,the miniaturization of a detector was achieved by coupling a commercial silicon PIN photodiode(SPPD)into a beamstop,aiming for it not only to acquire X-ray absorption fine structure(XAFS)spectra,but also to protect the subsequent two-dimensional detector from high-brilliance X-ray radiation damage in certain combination techniques.This mini SPPD detector coupled to a beamstop was used as the rear detector in both the conventional sampling scheme and novel high-frequency(HF)sampling scheme to collect the transmission XAFS spectra.Traditional ion chambers were also used to collect the transmission XAFS spectra,which were used as the reference.These XAFS spectra were quantitatively analyzed and compared;the results demonstrated that the XAFS spectra collected by this SPPD in both the conventional sampling scheme and HF sampling scheme are feasible.This study provides a new detector-selection scheme for the acquisition of the quick-scanning XAFS(QXAFS)and HF sampling XAFS spectra.The SPPD detector presented in this study can partially meet the requirements of detector miniaturization.展开更多
Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（C...Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.展开更多
Four 4H-SiCp-i-n ultraviolet(UV) avalanche photodiode(APD) samples PIN-0.1, PIN-0.35, PIN-0.5, and PIN-1.0 with different intrinsic layer thicknesses(0.1 μm, 0.35 μm, 0.5 μm, and 1.0 μm, respectively) are designed...Four 4H-SiCp-i-n ultraviolet(UV) avalanche photodiode(APD) samples PIN-0.1, PIN-0.35, PIN-0.5, and PIN-1.0 with different intrinsic layer thicknesses(0.1 μm, 0.35 μm, 0.5 μm, and 1.0 μm, respectively) are designed and fabricated.Single photon detection efficiency(SPDE) performance becomes better as the intrinsic layer thickness increases, which is attributed to the inhibitation of tunneling.Dark count origin is also investigated, an activation energy as small as 0.22 eV of the dark count rate(DCR) confirms that the trap-assisted tunneling(TAT) process is the main source of DCR.The temperature coefficient ranges from-2.6 mV/℃ to 18.3 mV/℃, demonstrating that the TAT process is dominant in APDs with thinner intrinsic layers.Additionally, the room temperature maximum quantum efficiency at 280 nm differs from 48% to 65% for PIN-0.35, PIN-0.5, and PIN-1.0 under 0 V bias, and UV/visible rejection ratios higher than 104 are obtained.展开更多
The performance of an InGaN/GaN multiple quantum well（MQW） based visible-light Schottky photodiode（PD）is improved by optimizing the source flow of TEGa during In Ga N QW growth. The samples with five-pair InGaN/Ga...The performance of an InGaN/GaN multiple quantum well（MQW） based visible-light Schottky photodiode（PD）is improved by optimizing the source flow of TEGa during In Ga N QW growth. The samples with five-pair InGaN/GaN MQWs are grown on sapphire substrates by metal organic chemical vapor deposition. From the fabricated Schottky-barrier PDs, it is found that the smaller the TEGa flow, the lower the reverse-bias leakage is. The photocurrent can also be enhanced by depositing the In GaN QWs with using lower TEGa flow. A high responsivity of 1.94 A/W is obtained at 470 nm and -3-V bias in the PD grown with optimized TEGa flow. Analysis results show that the lower TEGa flow used for depositing In Ga N may lead to superior crystalline quality with improved InGaN/GaN interface, and less structural defects related non-radiative recombination centers formed in the MQWs.展开更多
The sensing of a flame can be performed by using wide-bandgap semiconductors, which offer a high signal-to-noise ratio since they only response the ultraviolet emission in the flame. Diamond is a robust semiconductor ...The sensing of a flame can be performed by using wide-bandgap semiconductors, which offer a high signal-to-noise ratio since they only response the ultraviolet emission in the flame. Diamond is a robust semiconductor with a wide-bandgap of 5.5 e V, exhibiting an intrinsic solar-blindness for deep-ultraviolet(DUV) detection. In this work, by using a submicron thick boron-doped diamond epilayer grown on a type-Ib diamond substrate, a Schottky photodiode device structure- based flame sensor is demonstrated. The photodiode exhibits extremely low dark current in both forward and reverse modes due to the holes depletion in the epilayer. The photodiode has a photoconductivity gain larger than 100 and a threshold wavelength of 330 nm in the forward bias mode. CO and OH emission bands with wavelengths shorter than 330 nm in a flame light are detected at a forward voltage of-10 V. An alcohol lamp flame in the distance of 250 mm is directly detected without a focusing lens of flame light.展开更多
We report the edge-defined-film-fed(EFG)-grown β-Ga_(2)O_(3)-based Schottky photodiodes.The device has a reverse leakage current of ~nA and a rectified ratio of ~10^(4) at ±5 V.In addition,the photodiode detecto...We report the edge-defined-film-fed(EFG)-grown β-Ga_(2)O_(3)-based Schottky photodiodes.The device has a reverse leakage current of ~nA and a rectified ratio of ~10^(4) at ±5 V.In addition,the photodiode detector shows a dark current of 0.3 pA,a photo-responsivity(R) of 2.875 mA/W,a special detectivity(D*) of 10^(10) Jones,and an external quantum efficiency(EQE) of 1.4% at zero bias,illustrating a self-powered operation.This work may advance the development of the Ga_(2)O_(3)-based Schottky diode solar-blind photodetectors.展开更多
基金supported by the National Natural Science Foundation of China(Nos.62374035,92263106,12061131009)the Science and Technology Commission of Shanghai Municipality(No.21520712600).
文摘Silver nanowires(Ag NWs)have promising application potential in electronic displays because of their superior flexibility and transparency.Doping Ni in Ag NWs has proven to be an effective strategy to im-prove its work function.However,AgNi NWs-based electrodes suffer from poor electrical conductivity under air exposure due to the low-conductivity NiO generated on its surface.Here,Cu was further doped in AgNi NWs to form AgNiCu NWs and regulate its surface oxide under long-term air exposure.Finally,it is demonstrated that the conductivity of AgNiCu NWs can acquire an improved tolerable tempera-ture(over 240℃)and prolonged high-temperature tolerance time(over 150 min)by finely regulating the doping content Cu,indicating an enhanced air-stable conductivity.The optimized AgNiCu NWs also achieve superior transparent conductivity as pure Ag NWs and high work function as AgNi NWs,which has been successfully applied in constructing an n-type photodiode with an effective rectification effect.
基金supported in part by National Key Research and Development Program of China(No.2022YFB2803002)National Natural Science Foundation of China(Nos.62235005,62127814,62225405,61975093,61927811,61991443,61925104 and 61974080)Collaborative Innovation Centre of Solid-State Lighting and Energy-Saving Electronics.
文摘This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy structure and coplanar waveguide electrodes,the fabricated 4-μm-diameter PD exhibits ultra-flat frequency response and high saturation power.Integrated passive circuits including low-loss bias-tee and E-plane probe are designed to package the PD into a compact module with waveguide output.The packaged PD module has demonstrated a flat frequency response with fluctuations within±2.75 d B over a broadband of 140–220 GHz and a high saturated output power of-7.8 d Bm(166μW)at 140 GHz.For wireless communication applications,the packaged PD is used to implement 1-m free space transmission at carrier frequencies of 150.5 and 210.5 GHz,with transmission rates of 75 and 90 Gbps,respectively.
基金Supported by Shanghai Natural Science Foundation(22ZR1472600).
文摘The development of InGaAs/InP single-photon avalanche photodiodes(SPADs)necessitates the utiliza-tion of a two-element diffusion technique to achieve accurate manipulation of the multiplication width and the dis-tribution of its electric field.Regarding the issue of accurately predicting the depth of diffusion in InGaAs/InP SPAD,simulation analysis and device development were carried out,focusing on the dual diffusion behavior of zinc atoms.A formula of X_(j)=k√t-t_(0)+c to quantitatively predict the diffusion depth is obtained by fitting the simulated twice-diffusion depths based on a two-dimensional(2D)model.The 2D impurity morphologies and the one-dimensional impurity profiles for the dual-diffused region are characterized by using scanning electron micros-copy and secondary ion mass spectrometry as a function of the diffusion depth,respectively.InGaAs/InP SPAD devices with different dual-diffusion conditions are also fabricated,which show breakdown behaviors well consis-tent with the simulated results under the same junction geometries.The dark count rate(DCR)of the device de-creased as the multiplication width increased,as indicated by the results.DCRs of 2×10^(6),1×10^(5),4×10^(4),and 2×10^(4) were achieved at temperatures of 300 K,273 K,263 K,and 253 K,respectively,with a bias voltage of 3 V,when the multiplication width was 1.5µm.These results demonstrate an effective prediction route for accu-rately controlling the dual-diffused zinc junction geometry in InP-based planar device processing.
文摘The influence of thermal treatment on Si 1-x Ge x/Si multiple-quantum wells (MQW) p-i-n photodiodes has been investigated by photocurrent spectroscopy combined with X-ray double crystal diffraction.The cutoff wavelength is significantly reduced due to the Si-Ge interdiffusion and partial relaxation of the strained SiGe alloy.The values of the blue shift increase slowly with the annealing temperatures in the range of 750℃ to 850℃.However,the nonlinear changes in photocurrent intensities of the samples annealed at different temperatures have been observed,which is mainly dominated by the generation of misfit dislocations and the reduction of the point defects in the heating process.
文摘A different approach,using the molecular beam epitaxy (MBE)-grown ZnS-based Schottky photodiode technology,is applied to fabricate an 8×8 photodiode array.The micro-processing procedures of this photodiode array including standard photolithography,a number of metallisation,wet-chemical etching and SiO_2 deposition for insulation are developed.The detector is characterized to have a cutoff wavelength at 340 nm and the photo-responsivity measurements on the pixels result an ultraviolet (UV) response as high as 0.15 A/W,corresponding to an external quantum efficiency of 55% in the visible-blind spectral ranging from 400 down to 250nm.Imaging tests indicate that this array is able to capture the intensity profile of a given UV light source with reasonably good capability.
文摘The relationships between irradiation doses of γ ray and the main photoelectric characteristics of PIN photodiode or conventional photodiode with different structure were studied. The experimental results show that after the photodiodes being irradiated,the photocurrent decreases,especially for short wavelength of light. The dark current of the photodiodes with smaller active area decreases while increases for that with larger active area,and the response time shortens. The plane scanning experiment of laser beam indicates that the homogeneity of the device's surface is not influenced by the irradiation. The results prove that PIN photodiode shows relatively good radioresistance.
文摘A compact and stable three-port optical gate has been successfully fabricated by monolithically integrating a simple photodiode and an electroabsorption modulator. The gate shows an excellent DC logic ＂and＂ function with different load resistors. Its dynamical characteristics without packaging have also been measured. We observed a dynamic extinction ratio of over 7dB with a 95012 load resistor and a 7mW control light power at 622Mbit/s.
基金supported in part by National Key R&D Program of China under Grant No. 2016YFB0400902in part by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘4H-SiC single photon counting avalanche photodiodes(SPADs)are prior devices for weak ultraviolet(UV)signal detection with the advantages of small size,low leakage current,high avalanche multiplication gain,and high quantum efficiency,which benefit from the large bandgap energy,high carrier drift velocity and excellent physical stability of 4 H-SiC semiconductor material.UV detectors are widely used in many key applications,such as missile plume detection,corona discharge,UV astronomy,and biological and chemical agent detection.In this paper,we will describe basic concepts and review recent results on device design,process development,and basic characterizations of 4 H-SiC avalanche photodiodes.Several promising device structures and uniformity of avalanche multiplication are discussed,which are important for achieving high performance of 4 HSiC UV SPADs.
基金supported by the National Natural Science Foundation of China(No.61404132)the Fundamental Research Funds for the Central Universities(Nos.lzujbky-2015-302,lzujbky-2017-171,and lzujbky-2016-119)
文摘The effect of high-energy proton irradiation on GaN-based ultraviolet avalanche photodiodes(APDs) is investigated. The dark current of the GaN APD is calculated as a function of the proton energy and proton fluences. By considering the diffusion, generation–recombination, local hopping conductivity, band-to-band tunneling, and trap-assisted tunneling currents, we found that the dark current increases as the proton fluence increases, but decreases with increasing proton energy.
基金Supported by the Chinese Academy of Sciences Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics,Shanghai Branch,University of Science and Technology of Chinathe National Natural Science Foundation of China under Grant No 11405172
文摘Quantum random number generators adopting single negligible dead time of avalanche photodiodes （APDs） photon detection have been restricted due to the non- We propose a new approach based on an APD array to improve the generation rate of random numbers significantly. This method compares the detectors＇ responses to consecutive optical pulses and generates the random sequence. We implement a demonstration experiment to show its simplicity, compactness and scalability. The generated numbers are proved to be unbiased, post-processing free, ready to use, and their randomness is verified by using the national institute of standard technology statistical test suite. The random bit generation efficiency is as high as 32.8% and the potential generation rate adopting the 32× 32 APD array is up to tens of Gbits/s.
文摘Silicon photonics technology has drawn significant interest due to its potential for compact and high-performance photonic integrated circuits.The Ge-or III-V material-based avalanche photodiodes integrated on silicon photonics provide ideal high sensitivity optical receivers for telecommunication wavelengths.Herein,the last advances of monolithic and hetero-geneous avalanche photodiodes on silicon are reviewed,including different device structures and semiconductor systems.
基金Supported by the National Natural Science Foundation of China(No.U1605241)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZR116)the Natural Science Foundation of Fujian Province for Distinguished Young Scholars(No.2019J06023)。
文摘A two-dimensional(2D)organic-inorganic hybrid perovskite(OIHP)material is considered as a promising candidate for a long-term stable photodetector owing to its outstanding phase and environmental stability.Herein,we demonstrate a perovskite photodiode based on the DJ phase 2D perovskite(PDA)(MA)_(n-1)Pb_(n)I_(3n+1)(where PDA is 1,3-propylenediamine,MA is methylamine,nominal n=4).The best-performance device exhibits a high detectivity of 4.57×10^(11) Jones,a responsivity of 0.25 A·W^(-1) at 480 nm,a low dark current density of 9.60×10^(-4) mA cm^(-2),and a remarkable on/off ratio of 3.10×10^(5).The unencapsulated device can maintain 95%of the initial photocurrent density after 90 days under an ambient atmosphere with relative humidity(RH)of 65%,demonstrating its improved stability than the 3D counterpart.The excellent stability of the photodiode based on 2D perovskite promises its bright commercial application ftiture.
基金supported by Department of Science and Technology (DST) under the project SR/WOS-A/PS-06/2006by Defence Research and Development Organization (DRDO),Govt. of India under the project ERIP/ER/0503515/M01/847
文摘The effect of Al doping on the J-V characteristics sol-gel derived of ZnO/p-Si photodiodes was investigated.The resistivity of Si was 0.1Ω·cm.ZnO films annealed at 500℃ were of the best quality.To investigate the spectral response of the photodiodes,the J-V characteristics were measured under different monochromatic lights at wavelength 420,530,570 and 630 nm.The diodes exhibit strong responsivity in the blue region at 420 nm.The responsivity is 0.22 A/W for Al doped （0.8 wt pct） photodiode,whereas for the undoped photodiode,it was much lower.An estimate of the responsivity as a function of wavelength has been made in terms of the width of depletion region of photodiodes.
基金Project(61040061) supported by the National Natural Science Foundation of ChinaProject supported by Hunan Provincial Innovation Foundation for Postgraduate Students,China
文摘A novel device, lateral PIN photodiode gated by transparent electrode （LPIN PD-GTE） fabricated on fully-depleted SOI film was proposed. ITO film was adopted in the device as gate electrode to reduce the light absorption. Thin Si film was fully depleted under gate voltage to achieve low dark current and high photo4o-dark current ratio. The model of gate voltage was obtained and the numerical simulations were presented by ATLAS. Current-voltage characteristics of LPIN PD-GTE obtained in dark （dark current） and under 570 nm illumination （photo current） were studied to achieve the greatest photo-to-dark current ratio for active channel length from 2 to 12 /am. The results show that the photo-to-dark current ratio is 2.0×10^7, with dark current of around 5×10^-4 pA under VGK=0.6 V, PrN=5 mW/cm2, for a total area of 10μm×10μm in fully depleted SOI technology. Thus, the LPIN PD-GTE can be suitable for high-grade photoelectric systems such as blue DVD.
基金supported by the National Key R&D Program of China(Nos.2017YFA0403000 and 2017YFA0403100).
文摘Experimental techniques based on SR facilities have emerged with the development of synchrotron radiation(SR)sources.Accordingly,detector miniaturization has become significant for the development of SR experimental techniques.In this study,the miniaturization of a detector was achieved by coupling a commercial silicon PIN photodiode(SPPD)into a beamstop,aiming for it not only to acquire X-ray absorption fine structure(XAFS)spectra,but also to protect the subsequent two-dimensional detector from high-brilliance X-ray radiation damage in certain combination techniques.This mini SPPD detector coupled to a beamstop was used as the rear detector in both the conventional sampling scheme and novel high-frequency(HF)sampling scheme to collect the transmission XAFS spectra.Traditional ion chambers were also used to collect the transmission XAFS spectra,which were used as the reference.These XAFS spectra were quantitatively analyzed and compared;the results demonstrated that the XAFS spectra collected by this SPPD in both the conventional sampling scheme and HF sampling scheme are feasible.This study provides a new detector-selection scheme for the acquisition of the quick-scanning XAFS(QXAFS)and HF sampling XAFS spectra.The SPPD detector presented in this study can partially meet the requirements of detector miniaturization.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11774095,11722431 and 11621404the Shanghai Basic Research Project under Grant No 18JC1412200+2 种基金the National Key R&D Program of China under Grant No2016YFB0400904the Program of Introducing Talents of Discipline to Universities under Grant No B12024the Shanghai International Cooperation Project under Grant No 16520710600
文摘Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFB0400902)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Four 4H-SiCp-i-n ultraviolet(UV) avalanche photodiode(APD) samples PIN-0.1, PIN-0.35, PIN-0.5, and PIN-1.0 with different intrinsic layer thicknesses(0.1 μm, 0.35 μm, 0.5 μm, and 1.0 μm, respectively) are designed and fabricated.Single photon detection efficiency(SPDE) performance becomes better as the intrinsic layer thickness increases, which is attributed to the inhibitation of tunneling.Dark count origin is also investigated, an activation energy as small as 0.22 eV of the dark count rate(DCR) confirms that the trap-assisted tunneling(TAT) process is the main source of DCR.The temperature coefficient ranges from-2.6 mV/℃ to 18.3 mV/℃, demonstrating that the TAT process is dominant in APDs with thinner intrinsic layers.Additionally, the room temperature maximum quantum efficiency at 280 nm differs from 48% to 65% for PIN-0.35, PIN-0.5, and PIN-1.0 under 0 V bias, and UV/visible rejection ratios higher than 104 are obtained.
基金supported by the Science and Technology Major Project of Guangdong Province,China(Grant Nos.2014B010119003 and 2015B010112001)
文摘The performance of an InGaN/GaN multiple quantum well（MQW） based visible-light Schottky photodiode（PD）is improved by optimizing the source flow of TEGa during In Ga N QW growth. The samples with five-pair InGaN/GaN MQWs are grown on sapphire substrates by metal organic chemical vapor deposition. From the fabricated Schottky-barrier PDs, it is found that the smaller the TEGa flow, the lower the reverse-bias leakage is. The photocurrent can also be enhanced by depositing the In GaN QWs with using lower TEGa flow. A high responsivity of 1.94 A/W is obtained at 470 nm and -3-V bias in the PD grown with optimized TEGa flow. Analysis results show that the lower TEGa flow used for depositing In Ga N may lead to superior crystalline quality with improved InGaN/GaN interface, and less structural defects related non-radiative recombination centers formed in the MQWs.
基金supported by Grant-in-Aid for Scientific Research in the Ministry of Education,Culture,Sports,Science and Technology of the Japanese Government(No.18360341)
文摘The sensing of a flame can be performed by using wide-bandgap semiconductors, which offer a high signal-to-noise ratio since they only response the ultraviolet emission in the flame. Diamond is a robust semiconductor with a wide-bandgap of 5.5 e V, exhibiting an intrinsic solar-blindness for deep-ultraviolet(DUV) detection. In this work, by using a submicron thick boron-doped diamond epilayer grown on a type-Ib diamond substrate, a Schottky photodiode device structure- based flame sensor is demonstrated. The photodiode exhibits extremely low dark current in both forward and reverse modes due to the holes depletion in the epilayer. The photodiode has a photoconductivity gain larger than 100 and a threshold wavelength of 330 nm in the forward bias mode. CO and OH emission bands with wavelengths shorter than 330 nm in a flame light are detected at a forward voltage of-10 V. An alcohol lamp flame in the distance of 250 mm is directly detected without a focusing lens of flame light.
基金Project supported by BUPT Excellent Ph.D.Students Foundation(Grant No.CX2020314)the National Natural Science Foundation of China(Grant Nos.61774019,51572033,and 51572241)+1 种基金the Fund of State Key Laboratory of Information Photonics and Optical Communications(BUPT)the Fundamental Research Funds for the Central Universities,China。
文摘We report the edge-defined-film-fed(EFG)-grown β-Ga_(2)O_(3)-based Schottky photodiodes.The device has a reverse leakage current of ~nA and a rectified ratio of ~10^(4) at ±5 V.In addition,the photodiode detector shows a dark current of 0.3 pA,a photo-responsivity(R) of 2.875 mA/W,a special detectivity(D*) of 10^(10) Jones,and an external quantum efficiency(EQE) of 1.4% at zero bias,illustrating a self-powered operation.This work may advance the development of the Ga_(2)O_(3)-based Schottky diode solar-blind photodetectors.
