Dual-color short-wavelength infrared photodetector based on InGaAsSb/GaSb heterostructure

T D Nguyen,J O Kim,Y H Kim,E T Kim,Q L Nguyen,S J Lee

doi:10.1063/1.5020532

Abstract

We report the spectral response characteristics of a dual–band infrared photodetector based on nBn photodiode configuration–with GaSb and InGaAsSb absorption layers and a ternary layer of AlGaSb that serves as unipolar barrier in between—which has independent access to both sides. The resulting structure has detection capability in the short-wavelength infrared ranges, cut-off wavelength of 1.6 μm (SWIR1; GaSb) and 2.65 μm (SWIR2; InGaAsSb) depending on the applied bias. The dual-band photodetector was evaluated by current–voltage (I–V) characteristics, spectral response, and detectivity (D*). The measured values of D* at 300 K were 2.3 × 1012 cm·Hz1/2·W−1 (at 1.5 μm) and 2.1 × 1011 cm·Hz1/2·W−1 (at 2.25 μm).

Highlights

Infrared photodetectors (IPs) based on heterostructures of antimony (Sb) alloys having a cut-off wavelength in the short–wavelength infrared (SWIR) region (1.6–2.8 μm)[1,2,3] are useful for several applications including gas analysis, humidity monitoring, and spectrometry
Barrier detectors based on InAsSb ternary and InGaAsSb quaternary epilayers have been developed and commercialized by virtue of their inherent low–dark current characteristics, which enables operation at high temperature.[1,7,11]
The benefits of a unipolar barrier and absence of depletion layer were evident even as the total dark current was reduced by suppressing the surface leakage current in multiple n-p junction,[1] Shockley–Read–Hall (SRH) recombination in the depletion region,[12] and diffusion current associated with Auger process.[11]

Summary

Introduction

Infrared photodetectors (IPs) based on heterostructures of antimony (Sb) alloys having a cut-off wavelength (λc) in the short–wavelength infrared (SWIR) region (1.6–2.8 μm)[1,2,3] are useful for several applications including gas analysis, humidity monitoring, and spectrometry. Dual-color short-wavelength infrared photodetector based on InGaAsSb/GaSb heterostructure

Results

Conclusion