Material properties of InAs/GaSb type-II superlattices (SLs) are sensitive indicators of SL growth quality and of the eventual performance of devices made from these materials. In InAs/GaSb SLs, electrons move predominantly in the InAs layer, where they are affected by intrinsic and extrinsic scattering mechanisms, including interface roughness scattering (IRS).. The mid-infrared 7 ML InAs/8 ML GaSb superlattices (SLs) were grown by molecular beam epitaxy at growth temperatures between 370 and 430 C in order to study the intrinsic characteristic of background carriers.  Grown SLs were all residual p-type with carrier densities in the low 10¹¹ cm^-2, and a minimum density of 1.8x10¹¹ cm^-2 was obtained from the SL grown at 400 C.  With increasing growth temperature, the in-plane carrier mobility decreased from 8740 to 1400 cm²/Vs due to increased interfacial roughness, while the
photoluminescence intensity increased six fold due to a decrease in the nonradiative defect densities. Next, we report on a study of the in-plane carrier mobility in InAs/GaSb superlattices as a function of carrier density. Instead of using a number of differently doped samples, we use the persistent photoconductivity-effect to vary the carrier density over a wide range from n- to p-type in single samples and perform Hall effect measurements. Hence, our data are not obscured by sample to sample non-uniformities. We demonstrate that low-temperature in-plane mobilities are limited by screened interface roughness scattering (IRS), although present models of two-dimensional carrier screening of IRS lead to limited agreement with our data.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/20744 must be provided.