First Principles calculations on the electronic properties of the III-VII semiconductors, radiation detectors, TlBr and TlCl

In this work, we have investigated the electronic properties of the III-VII binary compound semiconductors TlBr and TlCl by means of first-principles density-functional total-energy calculation using the all-electron full potential linear augmented plane-wave method (FP-LAPW). The (FPLAPW) method was used within the density functional theory (DFT) along with the Engel-Vosko and (GGA96) exchange correlation potential. The energy bands along high symmetry directions, the density of states and valence charge density distributions cut through various planes are presented. The results have been discussed in terms of previously existing experimental and theoretical data, and comparisons with similar compounds have been made. Analysis of band structure suggests a direct and a pseudo-direct band gaps for both compounds.