On the origin of the 1-eV band in photoluminescence from Cd{sub 1-x}Zn{sub x}Te

Photoluminescence (PL) at 77 K from Cd{sub 1-x}Zn{sub x}Te samples (x = 0, 0.005 and 0.01) annealed at 900 deg. C and cadmium vapor pressure P{sub Cd} = 3 x 10{sup 4}-2 x 10{sup 5} Pa has been studied. It was found that the contribution of the 1-eV band to the spectrum-integrated PL from these samples is independent of P{sub Cd}, in contrast to Cd{sub 0.95}Zn{sub 0.05}Te samples in which this contribution increases up to {approx}90% as P{sub Cd} grows. The band is not shifted to shorter wavelengths as x becomes larger. The conclusion that Zn vacancies are involved in the formation of Cd{sub 1-x}Zn{sub x}Te properties is confirmed. The 1-eV band is attributed to capture of free holes to acceptor levels related to vacancies of both cadmium and zinc. These levels are closely spaced and, therefore, are difficult to resolve.