The effects of indium composition in InGaAs interlayer and on optical properties of GaSb/InGaAs QD material on morphology of GaSb/InGaAs quantum dots （QDs） system are studied. AFM images show that the change of the ...The effects of indium composition in InGaAs interlayer and on optical properties of GaSb/InGaAs QD material on morphology of GaSb/InGaAs quantum dots （QDs） system are studied. AFM images show that the change of the indium composition in InGaAs interlayer can alter the GaSb QD morphology. It is found that low indium composition in InGaAs interlayer can promote the formation of QDs, while high indium composition can inhibit the formation of QDs. The photoluminescence （PL） spectra of GaSb/InGaAs QDs at 8 K under low excitation power indicate that the third root of the excitation power is linear with the peak position, which provides a direct evidence for their luminescence belonging to type-Ⅱ material optical transition. The PL spectra at 8 K under an excitation power of 90row show that the optical properties of GaSb/InGaAs QD material system can be affected by the indium composition in the InGaAs interlayer, and the PL peak position is linear with the indium composition. The optical properties of GaSb/InGaAs QDs can be improved by adjusting the indium composition in the InGaAs interlayer.展开更多
InGaAs光电探测器因其优异的短波红外响应特性、低暗电流和高响应度,在红外成像、激光通信和光谱检测等领域具有广泛应用。光敏元作为探测器的核心结构,其面积大小不仅影响光通量的吸收效率,还关系到器件的空间分辨率和光电性能。然而,...InGaAs光电探测器因其优异的短波红外响应特性、低暗电流和高响应度,在红外成像、激光通信和光谱检测等领域具有广泛应用。光敏元作为探测器的核心结构,其面积大小不仅影响光通量的吸收效率,还关系到器件的空间分辨率和光电性能。然而,光敏元面积对光电流特性的具体影响规律仍需系统实验验证。为此,本文设计并制备了光敏元面积从30 × 30 μm2至500 × 500 μm2的InGaAs探测器样品,测试并分析了其在暗态和光照条件下的电流–电压(I-V)特性。结果表明,随着光敏面积的增加,光电流呈明显增强趋势,且I-V曲线形状保持一致,反映出材料制程的一致性。在暗态下,暗电流随光敏元面积的增大而增大,但单位面积暗电流密度基本稳定,说明其主要来源为体电流。在光照条件下,不同面积器件的光电流接近线性增长,验证了光敏面积对光响应能力的直接影响。研究结果为InGaAs光电探测器在高分辨率与多像元集成应用中的结构设计提供了重要参考。This InGaAs photodetector, with its excellent short-wavelength infrared response, low dark current, and high responsivity, has been widely applied in infrared imaging, laser communication, and spectral detection. As the core structure of the detector, the area of the photosensitive element not only affects the efficiency of light flux absorption but also relates closely to the spatial resolution and photoelectric performance of the device. However, the specific influence of the photosensitive area on photocurrent characteristics still requires systematic experimental verification. To this end, this study designs and fabricates InGaAs detector samples with photosensitive areas ranging from 30 × 30 μm2 to 500 × 500 μm2, and investigates their current-voltage (I-V) characteristics under both dark and illuminated conditions. The results show that as the photosensitive area increases, the photocurrent exhibits a significant rising trend, while the overall I-V curve shape remains consistent, reflecting the uniformity of the material fabrication process. Under dark conditions, the dark current increases with the photosensitive area, but the dark current density per unit area remains nearly constant, indicating that the primary source is bulk current. Under illumination, the photocurrent of devices with different areas increases nearly linearly, confirming the direct impact of the photosensitive area on light response capability. These findings provide valuable reference for structural design in high-resolution and multi-pixel integrated applications of InGaAs photodetectors.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
基金Supported by the Science and Technology Planning Projects of Guangdong Province under Grant Nos 2014B050505020,2015B010114007 and 2014B090904045the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20134407110008+1 种基金the Guangzhou Science and Technology Project of Guangdong Province under Grant No 2016201604030027the Zhongshan Science and Technology Project of Guangdong Province under Grant No 2013B3FC0003
文摘The effects of indium composition in InGaAs interlayer and on optical properties of GaSb/InGaAs QD material on morphology of GaSb/InGaAs quantum dots （QDs） system are studied. AFM images show that the change of the indium composition in InGaAs interlayer can alter the GaSb QD morphology. It is found that low indium composition in InGaAs interlayer can promote the formation of QDs, while high indium composition can inhibit the formation of QDs. The photoluminescence （PL） spectra of GaSb/InGaAs QDs at 8 K under low excitation power indicate that the third root of the excitation power is linear with the peak position, which provides a direct evidence for their luminescence belonging to type-Ⅱ material optical transition. The PL spectra at 8 K under an excitation power of 90row show that the optical properties of GaSb/InGaAs QD material system can be affected by the indium composition in the InGaAs interlayer, and the PL peak position is linear with the indium composition. The optical properties of GaSb/InGaAs QDs can be improved by adjusting the indium composition in the InGaAs interlayer.
文摘InGaAs光电探测器因其优异的短波红外响应特性、低暗电流和高响应度,在红外成像、激光通信和光谱检测等领域具有广泛应用。光敏元作为探测器的核心结构,其面积大小不仅影响光通量的吸收效率,还关系到器件的空间分辨率和光电性能。然而,光敏元面积对光电流特性的具体影响规律仍需系统实验验证。为此,本文设计并制备了光敏元面积从30 × 30 μm2至500 × 500 μm2的InGaAs探测器样品,测试并分析了其在暗态和光照条件下的电流–电压(I-V)特性。结果表明,随着光敏面积的增加,光电流呈明显增强趋势,且I-V曲线形状保持一致,反映出材料制程的一致性。在暗态下,暗电流随光敏元面积的增大而增大,但单位面积暗电流密度基本稳定,说明其主要来源为体电流。在光照条件下,不同面积器件的光电流接近线性增长,验证了光敏面积对光响应能力的直接影响。研究结果为InGaAs光电探测器在高分辨率与多像元集成应用中的结构设计提供了重要参考。This InGaAs photodetector, with its excellent short-wavelength infrared response, low dark current, and high responsivity, has been widely applied in infrared imaging, laser communication, and spectral detection. As the core structure of the detector, the area of the photosensitive element not only affects the efficiency of light flux absorption but also relates closely to the spatial resolution and photoelectric performance of the device. However, the specific influence of the photosensitive area on photocurrent characteristics still requires systematic experimental verification. To this end, this study designs and fabricates InGaAs detector samples with photosensitive areas ranging from 30 × 30 μm2 to 500 × 500 μm2, and investigates their current-voltage (I-V) characteristics under both dark and illuminated conditions. The results show that as the photosensitive area increases, the photocurrent exhibits a significant rising trend, while the overall I-V curve shape remains consistent, reflecting the uniformity of the material fabrication process. Under dark conditions, the dark current increases with the photosensitive area, but the dark current density per unit area remains nearly constant, indicating that the primary source is bulk current. Under illumination, the photocurrent of devices with different areas increases nearly linearly, confirming the direct impact of the photosensitive area on light response capability. These findings provide valuable reference for structural design in high-resolution and multi-pixel integrated applications of InGaAs photodetectors.
基金Supported by the National Natural Science Foundation of China(12027805,62171136,62174166,U2241219)the Science and Technology Commission of Shanghai Municipality(2019SHZDZX01,22JC1402902)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB43010200)。
基金Supported by the National Basic Research Program of China(2014CB643903,2013CB932904)the National Natural Science Foundation of China(61435012,61306088,61274013)
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.
