Growth of CdTe from Te excess solution and self-compensation of doped donor

Abstract

CdTe single crystals were grown from Te excess solution by the Bridgman method, and a donor species of group VII or III elements in the periodic table was added for compensating vacancy cadmium (V Cd) in the crystal. Electrical conductivity and photoluminescence spectra (PL) of as-grown crystals were measured to examine the incorporation of donors and its compensation state. The results suggested that the donor species are incorporated into the crystal in the order of I>Cl>F, In, and self-compensation occurred linked with the formation of a complex center such as a neutral complex center (V Cd −−·2D Te +)° or an acceptor complex center (V Cd −−·D Te +) −. Shallow trapping levels and deep acceptor levels due to the above complex center were clearly observed for In- and halogen-doped crystals, respectively.