Electrical and optical characterization of ion-implanted CuGaSe2 single crystals

CuGaSe2 single crystals were doped with B and Ge by ion implantation and analyzed by Hall effect, photoluminescence, and reflected second harmonic generation measurements. After ion implantation the crystals exhibited a destroyed surface structure. Measurements of the band edge photoluminescence and the second harmonic generation before and after annealing clearly reflected the thermal healing of the implantation-induced crystalline defects. As expected the analysis of the electrical measurements showed the incorporation of donor levels due to implantation with B and Ge, which led to electrically compensated samples. However no n-type conductivity could be obtained. This is ascribed to self-compensation of the defects for implantation ion doses higher than 10(15) cm(-2). (C) 1998 American Institute of Physics.