Temperature Dependence of Mid-Infrared Emission Process of InAs/GaSb Superlattices Grown by MOVPE

The mid-infrared emission of InAs/GaSb superlattices grown by MOVPE was compared with the calculated spectrum by perturbation method. Above 90 K, the emission from higher energy transitions is larger than those from the lowest levels.

1. Introduction

Mid-infrared wavelengths in the range of 2 to 15 µm have shown promise for highly sensitive gas sensing. For selective gas detection using specific absorption lines, low-cost semiconductor lasers operated at room temperature are expected [1]. InAs/GaSb type-II superlattices (SLs) cover this wavelength range by adjusting the layer thickness. In previous studies, many InAs/GaSb SLs have been reported by using molecular beam epitaxy (MBE) to achieve lattice matched on InAs substrates [2],[3]. In this paper, we report the photoluminescence (PL) of InAs/GaSb SL grown by MOVPE method. The emission transition was investigated by comparing with the spontaneous emission spectrum calculated by k · p perturbation method.