It was recalled that DX centers could be useful, and a study was made of II-VI semiconductors in search of suitable DX centers which could exist at 300K. Measurements of the photoconductivity and Hall effect in Cl-doped Cd1-xZnxTe showed that Cl donors formed 2 distinct DX states. Only one was detected when x was equal to 0·20. However, when x was equal to 0.28, transport measurements revealed an additional DX-like state into which photo-carriers were metastably captured. In the latter case, persistent photoconductivity existed at temperatures of up to 190K.

T.Thio, J.W.Bennett, D.J.Chadi, R.A.Linke, P.Becla: Journal of Crystal Growth, 1996, 159, 345-9