Hydrostatic pressure shift of absorption and photoluminescence in Cd0.45Mn0.55Te

Abstract

The absorption tail and the photoemission band in Cd_0.45Mn_0.55Te was studied under hydrostatic pressure up to 0.5 GPa. The pressure coefficients dE/dP are found to be negative and of the order of 600 cm^-1 GPa^-1. In comparison the coefficients for intrinsic absorption in CdTe at 1.5, 2.4, 3.9 and 4.0 eV although of the same order of magnitude are all known to be positive. This supports the idea that transitions between crystal field levels of the Mn²⁺ ions are responsible for the observed optical properties at high manganese concentrations. With the elastic constants of the alloy which were also measured in this work the authors derive dE/da and discuss the results in the framework of crystal field theory.