Effect of Si-doped and undoped inter-layer transition time on the strain-compensated InGaAs/InAlAs QCL active region grown with MOVPE

Abstract

In this study, we report the effect of the combination of Si-doped and undoped inter-layer transition time in the strain compensated In0.67Ga0.33As/In0.36Al0.64As quantum cascade laser (QCL) structure grown on InP substrate by Metal Organic Vapor Phase Epitaxy (MOVPE). In situ reflectance spectroscopy and high resolution X-ray diffraction (HRXRD) technique have been used for the analysis of growth steps and crystalline quality of QCL structures, respectively. In addition, since thickness accuracy is very important for QCLs, two different thickness calculation methods have been used in the Global Fit simulation program for detailed thickness accuracy of structures. As a result, optimum values for thickness accuracy have been obtained as 5 and 10 s between undoped and Si-doped layers, respectively, as verified by the two methods.