Optical characterization of Zn_0.35Cd_0.44Mg_0.21Se crystalline alloy by polarization‐dependent contactless electroreflectance measurements

Abstract

An optical study of wurtzite Zn0.35Cd0.44Mg0.21Se crystalline alloy grown by the modified high‐pressure Bridgman method was carried out by polarization‐dependent contactless electroreflectance (CER) and temperature‐dependent photoluminescence (PL) in the temperature range of 10–300 K. The CER experiment revealed three well known wurtzite crystal lattice related excitonic features A, B, and C in the vicinity of band edge. The excitonic features A and B showed polarization‐dependent character, where both A and B excitons are present for E⊥c polarization and only B exciton is observed for E‖c polarization. Low temperature PL spectra of the investigated sample consisted of the excitonic line, the “edge emission” due to radiative recombination of shallow donor‐acceptor pairs and a broad band related to recombination through deep level defects. In addition, the transition energies and broadening parameters of the band‐edge excitonic transitions were evaluated and discussed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)