In-situ spectroscopic characterisation of passivation layers on (Cd,Hg)Te

Abstract The growth of anodic sulphide films on CMT from aqueous solutions is investigated. In-situ spectroscopic ellipsometry and photocurrent measurements are used to characterise the surface films. The initial stages of growth appears to yield barrier-type films of CdS whereas the thicker films (>100 A) are shown to have a porous structure. Impurities are also incorporated during growth into the thicker sulphide layers which increase the light absorption below the band gap of CdS (2.42 eV).