V/III ratio effects on high quality InAlAs for quantum cascade laser structures

In this study we report the VIII ratio effects on growth, structural, optical and doping characteristics of low growth rate (similar to 1 angstrom/s) heteroepitaxial Metal Organic Chemical Vapor Deposition (MOCVD) grown In(x)A(1-x)As layers, a part of Quantum Cascade Laser (QCL) structures, on InP substrate. Especially photoluminescence (PL) properties of InAlAs-InP interface show strong dependence on AsH3 overpressure. We have shown that the VIII ratio with fixed metalorganic precursor flow is a crucial parameter on In In(x)A(1-x)As layers to have a good material quality in terms of crystallinity, optical and electrical characteristics with and without doping. (C) 2017 Elsevier Ltd. All rights reserved.