Photoelectrical and optical properties of Cd1-xMnxTe single crystals and thin films

The optical absorption spectra at the fundamental absorption edge and the photoconductivity kinetics of Cd1-xMnxTe (0 <= x <= 0.15) at 78-300 K have been studied. Single crystals were grown by Bridgman method. They show an enhanced photoconductivity in the vicinity of fundamental absorption threshold. The binary compounds CdTe and MnTe can form a continuous row of Cd1-xMnxTe solid solutions (on CdTe crystal lattice) in the range 0 < x < 0.85. At 293 K, the fundamental absorption red edge in crystals with x <= 0.05 is determined by the exciton absorption. The fundamental absorption edge has the specific shape of crystals with high impurity levels density. The nature of optical transitions at the absorption edge was established from the spectral dependences of both optical absorption and photoconductivity. The energies of localized states in the band gap of Cd1-xMnxTe crystals and thin films have been determined.