Weak response in long‐wavelength infrared(LWIR)detection has long been a perennial concern,significantly limiting the reliability of appli-cations.Avalanche photodetectors(APDs)offer excellent responsivity but are pl...Weak response in long‐wavelength infrared(LWIR)detection has long been a perennial concern,significantly limiting the reliability of appli-cations.Avalanche photodetectors(APDs)offer excellent responsivity but are plagued by high dark current during the multiplication process.Here,we propose a high‐performance type‐II superlattices(T2SLs)LWIR APD to address these issues.The low Auger recombination rate of the InAs/InAsSb T2SLs absorption layer is exploited to reduce the dark current initially.AlAsSb with a low k value is employed as the multiplication layer to suppress device noise while maintaining sufficient gain.To facilitate carrier transport,the conduction band discontinuity is opti-mized by inserting an InAs/AlSb T2SLs stepped grading layer between the absorption and multiplication layers.As a result,the device exhibits excellent photoresponse at 8.4μm at 100 K and maintains a low dark current density of 5.4810^(-2) A/cm^(2).Specifically,it achieves a maximum gain of 366,a responsivity of 650 A/W,and a quantum efficiency of 26.28%under breakdown voltage.This design offers a promising solution for the advancement of LWIR detection.展开更多
基金Fundamental Research Funds for the Central Universities,Grant/Award Number:ZYGX2019Z018National Natural Science Foundation of China,Grant/Award Number:61974014Innovation Group Project of Sichuan Province,Grant/Award Number:20CXTD0090。
文摘Weak response in long‐wavelength infrared(LWIR)detection has long been a perennial concern,significantly limiting the reliability of appli-cations.Avalanche photodetectors(APDs)offer excellent responsivity but are plagued by high dark current during the multiplication process.Here,we propose a high‐performance type‐II superlattices(T2SLs)LWIR APD to address these issues.The low Auger recombination rate of the InAs/InAsSb T2SLs absorption layer is exploited to reduce the dark current initially.AlAsSb with a low k value is employed as the multiplication layer to suppress device noise while maintaining sufficient gain.To facilitate carrier transport,the conduction band discontinuity is opti-mized by inserting an InAs/AlSb T2SLs stepped grading layer between the absorption and multiplication layers.As a result,the device exhibits excellent photoresponse at 8.4μm at 100 K and maintains a low dark current density of 5.4810^(-2) A/cm^(2).Specifically,it achieves a maximum gain of 366,a responsivity of 650 A/W,and a quantum efficiency of 26.28%under breakdown voltage.This design offers a promising solution for the advancement of LWIR detection.
