A type-II superlattice period with a modified InAs to GaSb thickness ratio for midwavelength infrared photodiode performance improvement

Abstract

We present a type-II superlattice period with a modified InAs to GaSb thickness ratio for midinfrared detection. In this kind of structure, the large electron-hole wave-function overlap and the low intrinsic carrier concentration lead to a significant signal-to-noise ratio enhancement. For the proof of concept, a sample designed with an InAs to GaSb thickness ratio close to 2 was grown. Comparison with standard design photodiodes shows an improvement of the differential resistance area product by one and a half decade while the quantum efficiency was more than doubled.

Interband cascade infrared photodetectors with enhanced electron barriers and p-type superlattice absorbers

“…INTRODUCTION Infrared (IR) photodetectors based on type-II InAs/GaSb superlattice (SL) structures have drawn much research interest, and are suitable for high-resolution thermal imaging applications. [1][2][3][4][5][6][7][8] The flexibility of the nearly lattice-matched AlSb/InAs/GaSb material system has allowed the development of many advanced concepts and designs, including double heterostructures with graded-gap W-structure 1 and Mstructure, 2 as well as unipolar-barrier detectors such as nBn, 3 pMp, 4 and complementary-barrier IR detectors (CBIRD). 5 The development of detectors based on these designs has resulted in devices that are comparable to the state-of-the-art mid-IR detectors, and has also given researchers a better understanding of how to exploit the properties of the type-II SL material in optimizing detectors for various applications.…”

Noise measurements for the performance analysis of infrared photodetectors

“…In this paragraph, we present noise measurements that were realised under varying incident power, on InAs/GaSb superlattice pin photodiodes [6].…”

Progress on type-II InAs/GaSb superlattice (T2SL) infrared photodetector : from MWIR to VLWIR spectral domains

“…7a) [8], Fig. 7b reports typical dark-current density J(V) curves of the diode where J value as low as 2x10 -7 A/cm 2 and a R 0 A value as high as 7x10…”