Effect of isochronal annealing on CdTe and the study of electrical properties of Au–CdTe Schottky devices

Abstract

Single-crystal CdTe was grown with the vapour phase technique. Dice were suitably etched and then annealed in air isochronally at different temperatures (473, 573, 673, and 773 K) for the same period of time (1 h). Schottky barriers were made by vacuum evaporation of gold onto the as-grown CdTe single-crystal substrate as well as onto the isochronally annealed substrates. The physical properties of Au–CdTe devices were studied as a function of temperature by electrical methods, such as capacitance–voltage and current–voltage analysis. The isochronal annealing technique was found to produce a significant change in the electrical properties, such as barrier height, carrier concentration, ideality factor, and forward-bias threshold, of the Au–CdTe Schottky diode. The observations are discussed in terms of the various theories of Schottky barrier formation. PACS No.: 73.30ty