Pt-CdTe Detectors Spectroscopic Performances and RBS and XRF Interface Composition Analysis

X- and Gamma-Ray spectroscopy measurements have been performed on differently prepared CdTe samples (as-grown or annealed, different surface treatments, etc.) with Pt electrodes deposited by electroless technique in order to extract the typical figures of merit of the material and the detectors. Moreover, Rutherford Backscattering Spectrometry (RBS) using 8 MeV
$^{7}{\hbox {Li}}^{+++}$
ions and X-Ray Fluorescence (XRF) using a Pd-anode X-Ray generator were performed to characterize the crystal surface as well as the semiconductor-electrode interface. The thickness, the stoichiometry and the concentration profiles of platinum, cadmium and tellurium present at the surface layers were determined. The distribution of Cd deficiency at the interface layers was profiled using simulations and showed complex profiles in the samples, that can greatly affect the electrical quality of the detectors. In addition, resistivity and mu-tau product mapping and electrical measurements have been performed for material characterization. The aim of this work is to understand and improve the structure of the material-electrode interface; in particular, to understand the effect of the annealing process on the fabrication of the contacts and, at the end, on the performances of the detectors. For this reason a large number of detectors have been produced applying various chemical surface treatments on as-grown and annealed material, in order to determine the best routine way to fabricate high-quality X- and Gamma-ray detectors to be used both as large size planar detectors and as elements of imaging systems in medical or industrial applications.