Abstract
In this study, we demonstrate 12 × 12 µm2 high-performance, dual-band, long-wavelength infrared (LWIR) photodetectors based on InAs/GaSb/AlSb type-II superlattices. The structure consists of two back-to-back heterojunction photodiodes with 2 µm-thick p-doped absorption regions. High quality dry etching combined with SiO2 passivation results in a surface resistivity value of 7.9 × 105 Ω cm for the longer (red) channel and little degradation of the electrical performance. The device reaches dark current density values of 4.5 × 10−4 A/cm2 for the longer (red) and 1.3 × 10−4 A/cm2 for the shorter (blue) LWIR channels at quantum efficiency saturation. It has 50% cut-off wavelengths of 8.3 and 11.2 µm for the blue and red channel, respectively, at 77 K in back-side illumination configuration and exhibits quantum efficiencies of 37% and 29%, respectively. This results in specific detectivity values of 2.5 × 1011 cm·Hz1/2/W and 1.3 × 1011 cm·Hz1/2/W at 77 K.
Original language | English (US) |
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Pages (from-to) | 51-54 |
Number of pages | 4 |
Journal | Solid-State Electronics |
Volume | 136 |
DOIs | |
State | Published - Oct 2017 |
Keywords
- Infrared imaging
- Photodetectors
- Photodiodes
- Solid state detectors
- Type-II superlattices
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering