A complete model of Metal-Semiconductor-Metal Photodetector(MSM-PD) is presented. It can be used in any circuit simulators. Simulated DC characteristics for a GaAs MSM-PD are in good agreement with reported results.
Fabrication and characterization of metal-semiconductor-metal ultraviolet （MSM UV） photodetector based on ZnO ultra thin （nano scale） films with Pd Schottky contact are reported. The ZnO thin film was grown on gla...Fabrication and characterization of metal-semiconductor-metal ultraviolet （MSM UV） photodetector based on ZnO ultra thin （nano scale） films with Pd Schottky contact are reported. The ZnO thin film was grown on glass substrate by thermal oxidation of preeposited zinc films using vacuum deposition technique. With applied voltage in the range from -3V to 3V, the contrast ratio, responsivity, and detectivity for an incident radiation of 0.1 mW at 365 nm wavelength were estimated. The proposed device exhibited a high gain which was attributed to the hole trapping at semiconductor-metal interface. I-V characteristics were studied and the parameters, such as ideality factor, leakage current, resistance-areaproduct, and barrier height, were extracted from the measured data.展开更多
4H-SiC based metal-semiconductor-metal (MSM) photodetectors with diverse spacing were designed, fabricated, and characterized, in which nickel Schottky contacts were needed. Current-voltage and spectral responsivity m...4H-SiC based metal-semiconductor-metal (MSM) photodetectors with diverse spacing were designed, fabricated, and characterized, in which nickel Schottky contacts were needed. Current-voltage and spectral responsivity measurements were carried out at room temperature. The fabricated 4 μm-spacing device showed a very low dark current (0.25 pA at 5 V bias voltage), a typical responsivity of 0.103 A/W at 20 V, and a peak re-sponse wavelength at 290 nm. The fabricated devices held a high DUV to visible re-jection ratio of >103.展开更多
A two-dimensional model of a 4H-SiC metal-semiconductor-metal（MSM） ultraviolet photodetector has been established using a self-consistent numerical calculation method.The structure-dependent spectral response of a 4...A two-dimensional model of a 4H-SiC metal-semiconductor-metal（MSM） ultraviolet photodetector has been established using a self-consistent numerical calculation method.The structure-dependent spectral response of a 4H-SiC MSM detector is calculated by solving Poisson＇s equation,the current continuity equation and the current density equation.The calculated results are verified with experimental data.With consideration of the reflection and absorption on the metal contacts,a detailed study involving various electrode heights（H）,spacings （S） and widths（W） reveals conclusive results in device design.The mechanisms responsible for variations of responsivity with those parameters are analyzed.The findings show that responsivity is inversely proportional to electrode height and is enhanced with an increase of electrode spacing and width.In addition,the ultraviolet （UV）-to-visible rejection ratio is 103.By optimizing the device structure at 10 V bias,a responsivity as high as 180.056 mA/W,a comparable quantum efficiency of 77.93%and a maximum UV-to-visible rejection ratio of 1875 are achieved with a detector size of H = 50 nm,S =9μm and W = 3μm.展开更多
In this work,β-Ga_(2)O_(3)thin films were grown on SiO_(2)substrate by atomic layer deposition(ALD)and annealed in N_(2)atmosphere to enhance the crystallization quality of the thin films,which were verified from X-r...In this work,β-Ga_(2)O_(3)thin films were grown on SiO_(2)substrate by atomic layer deposition(ALD)and annealed in N_(2)atmosphere to enhance the crystallization quality of the thin films,which were verified from X-rays diffraction(XRD).Based on the grownβ-Ga_(2)O_(3)thin films,vertical metal-semiconductor-metal(MSM)interdigital photodetectors(PDs)were fabricated and investigated.The PDs have an ultralow dark current of 1.92 pA,ultra-high photo-to-dark current ratio(PDCR)of 1.7×10^(6),and ultra-high detectivity of 4.25×10^(14)Jones at a bias voltage of 10 V under 254 nm deep ultraviolet(DUV).Compared with the horizontal MSM PDs under the same process,the PDCR and detectivity of the fabricated vertical PDs are increased by 1000 times and 100 times,respectively.In addition,the vertical PDs possess a high responsivity of 34.24 A/W and an external quantum efficiency of 1.67×10^(4)%,and also exhibit robustness and repeatability,which indicate excellent performance.Then the effects of electrode size and external irradiation conditions on the performance of the vertical PDs continued to be investigated.展开更多
Based on thermionic emission theory,a model of a 6H-SiC metal-semiconductor-metal（MSM） ultraviolet photodetector is established with the simulation package ISE-TCAD.A device with 3μm electrode width（W） and 3μm e...Based on thermionic emission theory,a model of a 6H-SiC metal-semiconductor-metal（MSM） ultraviolet photodetector is established with the simulation package ISE-TCAD.A device with 3μm electrode width（W） and 3μm electrode spacing（L） is simulated.The findings show that the MSM photodetector has quite a low dark current of 15 pA at 10V bias and the photocurrent is two orders of magnitude higher than the dark current.The influences of different structures on dark and illuminated current-voltage characteristics of the MSM photodetector are investigated to optimize the device parameters.Simulation results indicate that the maximum photocurrent and the highest ratio of photocurrent to dark current at 15 V bias are 5.3 nA and 327 with device parameters of W=6μm,L=3μm and W =3μm,L=6μm,respectively.展开更多
Metal-semiconductor-metal photodetectors on semi-insulating Ga As with interdigital electrodes showed significant enhancement in the spectral response in the near-infrared region as the electrode spacing is reduced. T...Metal-semiconductor-metal photodetectors on semi-insulating Ga As with interdigital electrodes showed significant enhancement in the spectral response in the near-infrared region as the electrode spacing is reduced. The photocurrent for the device with 5 μm interdigital spacing is five orders of magnitude higher than the dark current, and the room temperature detectivity is on the order of 2.4 × 1012cm Hz1∕2W-1at 5 V bias. Furthermore,the spectral response of this device possesses strong dependence on the polarization of incident light showing potential plasmonic effects with only microscale dimensions. These experimental data were analyzed using optical simulation to confirm the response of the devices.展开更多
A two-dimensional model of a metal-semiconductor-metal （MSM） ZnO-based photodetector （PD） is developed. The PD is based on a drift diffusion model of a semiconductor that allows the calculation of potential distri...A two-dimensional model of a metal-semiconductor-metal （MSM） ZnO-based photodetector （PD） is developed. The PD is based on a drift diffusion model of a semiconductor that allows the calculation of potential distribution inside the structure, the transversal and longitudinal distributions of the electric field, and the distribution of carrier concentration. The ohmicity of the contact has been confirmed. The dark current of MSM PD based ZnO for different structural dimensions are likewise calculated. The calculations are comparable with the experimental results. Therefore, the influence with respect to parameters s （finger spacing） and w （finger width） is studied, which results in the optimization of these parameters. The best optimization found to concur with the experimental results is s = 16 μm, w = 16 μm, l = 250 μm, L = 350 μm, where l is the finger length and L is the length of the structure. This optimization provides a simulated dark current eaual to 24.5 nA at the polarization of 3 V.展开更多
A novel semicircular electrode metal-semiconductor-metal（SEMSM） ultraviolet detector is modeled, investigated and characterized with a self-consistent numerical calculation method.For the purpose of model and perfor...A novel semicircular electrode metal-semiconductor-metal（SEMSM） ultraviolet detector is modeled, investigated and characterized with a self-consistent numerical calculation method.For the purpose of model and performance verification,a comprehensive comparison of the SEMSM detector and a conventional electrode MSM detector is carried out with experimental data.The results indicate that the physical models are able to predict the enhanced device features.Moreover,the structural parameters have been adjusted appropriately to optimize the SEMSM detector.The findings show that a device with a 2μm finger radius and 3 /mi spacing exhibits outstanding characteristics in terms of a peak responsivity of 0.177 A/W at 290 nm,a maximum external quantum efficiency of over 75%,and a comparable normalized photocurrent to dark current ratio of 1.192×10^（-1） W^（-1） at 0.3 V bias. These results demonstrate that the SEMSM detector has excellent performance for optoelectronic integrated circuit applications.展开更多
A metal-semiconductor-metal (MSM) ultraviolet photodetector has been fabricated using unintentionally doped n-GaN films grown on sapphire substrates. Its dark current, photocurrent under the illumination with λ = 360...A metal-semiconductor-metal (MSM) ultraviolet photodetector has been fabricated using unintentionally doped n-GaN films grown on sapphire substrates. Its dark current, photocurrent under the illumination with λ = 360 nm light, responsivity, and the dependence of responsivity on bias voltage were measured at room temperature. The dark current of the photodetector is 1.03 Na under 5 V bias, and is 15.3 Na under 10 V bias. A maximum responsivity of 0.166 A/W has been achieved under the illumination with λ= 366 nm light and 15 V bias. It exhibits a typical sharp band-edge cutoff at the wavelength of 366 nm, and a high responsivity at the wavelength from 320 nm to 366 nm. Its responsivity under the illumination with λ= 360 nm light increases when the bias voltage increases.展开更多
Unintentionally doped AlGaN thin films are grown on c-plane(0001) sapphire substrate by metal-organic chemical vapor deposition, and low-temperature AlN is deposited onto sapphire substrate used as a bu?er layer. AlGa...Unintentionally doped AlGaN thin films are grown on c-plane(0001) sapphire substrate by metal-organic chemical vapor deposition, and low-temperature AlN is deposited onto sapphire substrate used as a bu?er layer. AlGaN metal-semiconductor-metal ultraviolet photodetectors with Ni/Au interdigitated contact electrodes are then fabricated by lift-off technology. The dark current of the AlGaN photodetectors is 5.61×10-9 A at 2-V applied bias and the peak response occurrs at 294 nm.展开更多
文摘A complete model of Metal-Semiconductor-Metal Photodetector(MSM-PD) is presented. It can be used in any circuit simulators. Simulated DC characteristics for a GaAs MSM-PD are in good agreement with reported results.
基金support by Indo-Iraq Cultural Exchange Program of ICCR (Indian Council for Cultural Relations)
文摘Fabrication and characterization of metal-semiconductor-metal ultraviolet （MSM UV） photodetector based on ZnO ultra thin （nano scale） films with Pd Schottky contact are reported. The ZnO thin film was grown on glass substrate by thermal oxidation of preeposited zinc films using vacuum deposition technique. With applied voltage in the range from -3V to 3V, the contrast ratio, responsivity, and detectivity for an incident radiation of 0.1 mW at 365 nm wavelength were estimated. The proposed device exhibited a high gain which was attributed to the hole trapping at semiconductor-metal interface. I-V characteristics were studied and the parameters, such as ideality factor, leakage current, resistance-areaproduct, and barrier height, were extracted from the measured data.
文摘4H-SiC based metal-semiconductor-metal (MSM) photodetectors with diverse spacing were designed, fabricated, and characterized, in which nickel Schottky contacts were needed. Current-voltage and spectral responsivity measurements were carried out at room temperature. The fabricated 4 μm-spacing device showed a very low dark current (0.25 pA at 5 V bias voltage), a typical responsivity of 0.103 A/W at 20 V, and a peak re-sponse wavelength at 290 nm. The fabricated devices held a high DUV to visible re-jection ratio of >103.
基金Project supported by the Pre-Research Foundation from the National Ministries and Commissions(Nos.51323040118,513080302)
文摘A two-dimensional model of a 4H-SiC metal-semiconductor-metal（MSM） ultraviolet photodetector has been established using a self-consistent numerical calculation method.The structure-dependent spectral response of a 4H-SiC MSM detector is calculated by solving Poisson＇s equation,the current continuity equation and the current density equation.The calculated results are verified with experimental data.With consideration of the reflection and absorption on the metal contacts,a detailed study involving various electrode heights（H）,spacings （S） and widths（W） reveals conclusive results in device design.The mechanisms responsible for variations of responsivity with those parameters are analyzed.The findings show that responsivity is inversely proportional to electrode height and is enhanced with an increase of electrode spacing and width.In addition,the ultraviolet （UV）-to-visible rejection ratio is 103.By optimizing the device structure at 10 V bias,a responsivity as high as 180.056 mA/W,a comparable quantum efficiency of 77.93%and a maximum UV-to-visible rejection ratio of 1875 are achieved with a detector size of H = 50 nm,S =9μm and W = 3μm.
基金the Natural Science Basic Research Program in Shaanxi Province of China(2023-JC-YB-574)the National Natural Science Foundation of China(62304178)。
文摘In this work,β-Ga_(2)O_(3)thin films were grown on SiO_(2)substrate by atomic layer deposition(ALD)and annealed in N_(2)atmosphere to enhance the crystallization quality of the thin films,which were verified from X-rays diffraction(XRD).Based on the grownβ-Ga_(2)O_(3)thin films,vertical metal-semiconductor-metal(MSM)interdigital photodetectors(PDs)were fabricated and investigated.The PDs have an ultralow dark current of 1.92 pA,ultra-high photo-to-dark current ratio(PDCR)of 1.7×10^(6),and ultra-high detectivity of 4.25×10^(14)Jones at a bias voltage of 10 V under 254 nm deep ultraviolet(DUV).Compared with the horizontal MSM PDs under the same process,the PDCR and detectivity of the fabricated vertical PDs are increased by 1000 times and 100 times,respectively.In addition,the vertical PDs possess a high responsivity of 34.24 A/W and an external quantum efficiency of 1.67×10^(4)%,and also exhibit robustness and repeatability,which indicate excellent performance.Then the effects of electrode size and external irradiation conditions on the performance of the vertical PDs continued to be investigated.
基金Project supported by the Pre-Research Foundation from the National Ministries and Commissions,China(Nos.51323040118, 513080302).
文摘Based on thermionic emission theory,a model of a 6H-SiC metal-semiconductor-metal（MSM） ultraviolet photodetector is established with the simulation package ISE-TCAD.A device with 3μm electrode width（W） and 3μm electrode spacing（L） is simulated.The findings show that the MSM photodetector has quite a low dark current of 15 pA at 10V bias and the photocurrent is two orders of magnitude higher than the dark current.The influences of different structures on dark and illuminated current-voltage characteristics of the MSM photodetector are investigated to optimize the device parameters.Simulation results indicate that the maximum photocurrent and the highest ratio of photocurrent to dark current at 15 V bias are 5.3 nA and 327 with device parameters of W=6μm,L=3μm and W =3μm,L=6μm,respectively.
基金supported by the Air Force Office of Scientific Research (Grant No. FA9550-10-1-0136)NASA (Grant No. 242026-1BBX11AQ36A)+1 种基金supported by a University of Arkansas Honors College Undergraduate Research grantthe Microelectronics–Photonics program at the University of Arkansas for the COMSOL license
文摘Metal-semiconductor-metal photodetectors on semi-insulating Ga As with interdigital electrodes showed significant enhancement in the spectral response in the near-infrared region as the electrode spacing is reduced. The photocurrent for the device with 5 μm interdigital spacing is five orders of magnitude higher than the dark current, and the room temperature detectivity is on the order of 2.4 × 1012cm Hz1∕2W-1at 5 V bias. Furthermore,the spectral response of this device possesses strong dependence on the polarization of incident light showing potential plasmonic effects with only microscale dimensions. These experimental data were analyzed using optical simulation to confirm the response of the devices.
文摘A two-dimensional model of a metal-semiconductor-metal （MSM） ZnO-based photodetector （PD） is developed. The PD is based on a drift diffusion model of a semiconductor that allows the calculation of potential distribution inside the structure, the transversal and longitudinal distributions of the electric field, and the distribution of carrier concentration. The ohmicity of the contact has been confirmed. The dark current of MSM PD based ZnO for different structural dimensions are likewise calculated. The calculations are comparable with the experimental results. Therefore, the influence with respect to parameters s （finger spacing） and w （finger width） is studied, which results in the optimization of these parameters. The best optimization found to concur with the experimental results is s = 16 μm, w = 16 μm, l = 250 μm, L = 350 μm, where l is the finger length and L is the length of the structure. This optimization provides a simulated dark current eaual to 24.5 nA at the polarization of 3 V.
基金Project supported by the Pre-Research Foundation from the National Ministries and Commissions of China(Nos.51323040118. 513080302)
文摘A novel semicircular electrode metal-semiconductor-metal（SEMSM） ultraviolet detector is modeled, investigated and characterized with a self-consistent numerical calculation method.For the purpose of model and performance verification,a comprehensive comparison of the SEMSM detector and a conventional electrode MSM detector is carried out with experimental data.The results indicate that the physical models are able to predict the enhanced device features.Moreover,the structural parameters have been adjusted appropriately to optimize the SEMSM detector.The findings show that a device with a 2μm finger radius and 3 /mi spacing exhibits outstanding characteristics in terms of a peak responsivity of 0.177 A/W at 290 nm,a maximum external quantum efficiency of over 75%,and a comparable normalized photocurrent to dark current ratio of 1.192×10^（-1） W^（-1） at 0.3 V bias. These results demonstrate that the SEMSM detector has excellent performance for optoelectronic integrated circuit applications.
基金the National High Technology Research and Development Program of China(Grant No. 2001AA313050).
文摘A metal-semiconductor-metal (MSM) ultraviolet photodetector has been fabricated using unintentionally doped n-GaN films grown on sapphire substrates. Its dark current, photocurrent under the illumination with λ = 360 nm light, responsivity, and the dependence of responsivity on bias voltage were measured at room temperature. The dark current of the photodetector is 1.03 Na under 5 V bias, and is 15.3 Na under 10 V bias. A maximum responsivity of 0.166 A/W has been achieved under the illumination with λ= 366 nm light and 15 V bias. It exhibits a typical sharp band-edge cutoff at the wavelength of 366 nm, and a high responsivity at the wavelength from 320 nm to 366 nm. Its responsivity under the illumination with λ= 360 nm light increases when the bias voltage increases.
基金supported by the National Natural Science Foundation of China(No.61006052)the Fundamental Research Funds for the Central Universities(No.K5051325009)
文摘Unintentionally doped AlGaN thin films are grown on c-plane(0001) sapphire substrate by metal-organic chemical vapor deposition, and low-temperature AlN is deposited onto sapphire substrate used as a bu?er layer. AlGaN metal-semiconductor-metal ultraviolet photodetectors with Ni/Au interdigitated contact electrodes are then fabricated by lift-off technology. The dark current of the AlGaN photodetectors is 5.61×10-9 A at 2-V applied bias and the peak response occurrs at 294 nm.
