Photoluminescence study on the effects of the surface of CdTe by surface passivation

The etching effects on the CdTe surface treated by the different chemical etchants, such as 2% Br-methanol (BM) and 2% Br-20% latic acid in ethylene glycol (BLE) solutions are studied by both photoluminescence (PL) and atomic force microscopy. After etching, the dielectric materials ZnS and CdZnTe are used for the passivation of the CdTe surface. The PL studies of the CdTe surfaces passivated by the dielectrics are carried out, and the results are correlated with the value of the lifetime of the CdTe. The results show that the etching of CdTe surface by BLE solution yields the better surface condition for CdTe. The surface trap states of CdTe are reduced by the CdZnTe and ZnS passivant which results in the increase in the surface lifetime of CdTe.