Study of the effect of dislocations introduced by indentation on Cd(111) and Te((1)over-bar (1)over-bar (1)over-bar) faces on the electrical and optical properties of CdTe

Experimental studies are conducted to investigate the influence of dislocations on the electrical and optical properties of CdTe crystals. The microindentation technique is performed at room temperature to generate dislocations on the Cd(1 1 1) and Te((1) over bar (1) over bar (1) over bar) faces of nonintentionally doped n-type CdTe crystals. The effect of the generated dislocations is characterised by means of C-V measurements and photoluminescence experiments. The analysis of the results obtained confirms both the reduction of the donor concentration, essentially due to Cd vacancies, and the increase in the band-gap width. In addition, this analysis confirms the fact that the long arms of the indentation rosette consist of Cd(g)-type dislocations on the Cd face and Te(g)-type dislocations on the Te face. Finally, this study allows to specify the kind of majority defect on each face, V-Cd on Te face and V-Te on Cd face. (C) 2000 Elsevier Science B.V. All rights reserved.