Bias-selectable dual-band mid-/long-wavelength infrared photodetectors based on InAs/InAs1−xSbx type-II superlattices

Abstract

A high performance bias-selectable mid-/long-wavelength infrared photodetector based on InAs/InAs1−xSbx type-II superlattices on GaSb substrate has been demonstrated. The mid- and long-wavelength channels' 50% cut-off wavelengths were ∼5.1 and ∼9.5 μm at 77 K. The mid-wavelength channel exhibited a quantum efficiency of 45% at 100 mV bias voltage under front-side illumination and without any anti-reflection coating. With a dark current density of 1 × 10−7 A/cm2 under 100 mV applied bias, the mid-wavelength channel exhibited a specific detectivity of 8.2 × 1012 cm·Hz/W at 77 K. The long-wavelength channel exhibited a quantum efficiency of 40%, a dark current density of 5.7 × 10−4 A/cm2 under −150 mV applied bias at 77 K, providing a specific detectivity value of 1.64 × 1011 cm·Hz/W.

Flexible Broadband Image Sensors with SnS Quantum Dots/Zn2SnO4 Nanowires Hybrid Nanostructures

“…For a complex environment, this technology will have a huge advantage compared to single‐band imaging technology in target discrimination and identification by providing broadband information . To promote the development of broadband imaging technology, photodetectors with a broad spectral response have been studied widely . For example, Hu and co‐workers reported a vertical heterostructure of broadband photodetector array based on 2D GaSe/GaSb for visible (vis) and near infrared (NIR) imaging .…”

“…Razeghi et al fabricated a high‐performance bias‐selectable infrared photodetector array based on InAs/GaSb Type‐II superlattices for mid‐/long‐wavelength infrared imaging . However, conventional broadband image sensors are usually fabricated on rigid substrates, such as SiO 2 /Si, GaSb, GaN, sapphire, and so on, which are fragile, inflexible, weighty, and high‐cost, which limit the practical application of broadband image sensors in the future …”

“…During the past years, broadband imaging technology has attracted enormous attention due to the wide applications in plenty of fields, including biological medicine, mineral exploration, optical communication, and day and night monitoring. [1][2][3][4] For a complex environment, this technology will have a huge advantage compared to single-band imaging technology in target discrimination and identification by providing broadband information. [1] To promote the development of broadband imaging technology, photodetectors with a broad spectral response have been studied widely.…”

“…[3] However, conventional broadband image sensors are usually fabricated on rigid substrates, such as SiO 2 /Si, GaSb, GaN, sapphire, and so on, which are fragile, inflexible, weighty, and high-cost, which limit the practical application of broadband image sensors in the future. [2][3][4] Due to the obvious limitations of conventional electronic devices based on rigid substrates, the demand for electronics with features of being flexible, light-weight, wearable, and low-cost is growing, and flexible electronics have developed very fast in the past several years. [5] As one of the important flexible electronic devices, flexible image sensors have also gained considerable research interest and some exciting results were achieved.…”

Surface passivation of (100) GaSb using self-assembled monolayers of long-chain octadecanethiol

“…In particular, type-II InAs/GaSb superlattice (T2SL) is attractive for the third generation of infrared photodetectors as an alternative material system to HgCdTe alloy for improved stability, reduced Auger recombination and unwanted tunneling currents. 1,2 It is well known that GaSb exhibits the chemically active surface, therefore, Sb-based devices suffer from the rapid oxidation of the surface in the air inducing high surface-leakage currents. Additionally, an elemental Sb may occur at the oxide/GaSb interface, giving rise to the conduction path parallel to the interface.…”