X-ray photoemission analysis of chemically treated GaTe semiconductor surfaces for radiation detector applications

The surface of the layered III-VI chalcogenide semiconductor GaTe was subjected to various chemical treatments commonly used in device fabrication to determine the effect of the resulting microscopic surface composition on transport properties. Various mixtures of H₃PO₄:H₂O₂:H₂O were accessed and the treated surfaces were allowed to oxidize in air at ambient temperature. High-resolution core-level photoemission measurements were used to evaluate the subsequent chemistry of the chemically treated surfaces. Metal electrodes were created on laminar (cleaved) and nonlaminar (cut and polished) GaTe surfaces followed by chemical surface treatment and the current versus voltage characteristics were measured. The measurements were correlated to understand the effect of surface chemistry on the electronic structure at these surfaces with the goal of minimizing the surface leakage currents for radiation detector devices.