InAs/InAsSb Strain-Balanced Superlattices for Longwave Infrared Detectors.

Tetiana Manyk,Piotr Martyniuk,Krzysztof Murawski,Jaroslaw Rutkowski,Krystian Michalczewski

doi:10.3390/s19081907

Abstract

The InAs/InAsSb type-II superlattices (T2SLs) grown on a GaSb buffer layer and GaAs substrates were theoretically investigated. Due to the stability at high operating temperatures, T2SLs could be used for detectors operating in the longwave infrared (LWIR) range for different sensors to include, e.g., CH4 and C2H6 detection, which is very relevant for health condition monitoring. The theoretical calculations were carried out by the 8 × 8 k·p method. The estimated electrons and heavy holes probability distribution in a InAs/InAsSb superlattice (SL) shows that the wave function overlap increases while the thickness of the SL period decreases. The change in the effective masses for electrons and holes versus the SL period thickness for the kz-direction of the Brillouin zone is shown. The structures with a period lower than 15 nm are more optimal for the construction of LWIR detectors based on InAs/InAsSb SLs. The experimental results of InAs/InAsSb T2SLs energy bandgap were found to be comparable with the theoretical one. The proper fitting of theoretically calculated and experimentally measured spectral response characteristics in terms of a strain-balanced and unbalanced structures is shown.

Highlights

Smith et al [1] in 1987 proposed the use of type-II superlattices (T2SLs) InAs/GaSb as optoelectronic materials exhibiting excellent electro-optical properties, theoretically comparable to HgCdTe being the main compound for detection in the infrared radiation (IR) region [2]
Owing to these unique properties, T2SLs InAs/InAsSb have been chosen as materials for applications in the longwave infrared radiation (LWIR) detectors operating within the 8–15 μm range
We present a comparison of the responsivity of high operating industry, and automotive, such as railway safety, gas leak detection, flame detection, heat distribution temperature (HOT)diagnostic

Summary

Introduction

Smith et al [1] in 1987 proposed the use of type-II superlattices (T2SLs) InAs/GaSb as optoelectronic materials exhibiting excellent electro-optical properties, theoretically comparable to HgCdTe being the main compound for detection in the infrared radiation (IR) region [2]. By adjustment of the InAs and/or InAsSb thickness as well as the Sb molar composition (xSb ), it is feasible to tune Eg within a wide range of IR Owing to these unique properties, T2SLs InAs/InAsSb have been chosen as materials for applications in the longwave infrared radiation (LWIR) detectors operating within the 8–15 μm range. This could be allowed by e.g., the C2H6 2level of 10 stress, or 19, even monitoring through unexplored LWIR, requiring a proper detector operating in that range. Be allowed by e.g., the schematic of the unexplored energy bands of therequiring strained aand unstrained is

H6 levelrepresentation monitoring through

Influence the Period the Superlattice

These simulations are at for

34.3 ML in ML InAsSb

Conclusions