Effet de l'hydrogène sur les défauts ponctuels dans CdTe et CdZnTe

Abstract

The whole of this work is based on the study of the effect of the polarity and particularly on the hydrogenation on the electrical and optical properties of n type CdTe and p type CdZnTe. for this, electrical measurements by means of I(V) and C(V), and optical characterisations by the help of photoluminescence, infrared absorption spectroscopy and UV-Visible spectroscopy have been used . Measurement of the barrier height on both faces (111) and (111) leads to identify, for any time, the kind of majority defect, which stopped the Fermi level, and which is either the Cd vacancy (VCJ), or the Te vacancy (Vic), or even the complex [Vcd, Cu|. 'The determination of the doping concentration on the one hand and the peaks of the photoluminescence intensity related to donors, acceptors and deep levels, on the other hand leads to confirm that the hydrogen reduces the electrical activity of the dopants and passives some deep levels related to native defects or to impurities making up neutral complexes. The increase of the absorption optical edge after hydrogenation is explained in terms of passivation of acceptors. The interaction hydrogen-impurity was confirmed by the help of IR spectroscopy, which gives molecules such CuH and LiH