Raman and photoluminescence characterizations of electrochemically deposited Zn_x Cd_1-x S layers

摘要

CdS, ZnS and Zn_xCd_1-xS alloy were deposited from acidic solutions by the electrochemical technique, and character- ized mainly by optical methods. Raman scattering was observed even for as-deposited films, and the alloy composition x was determined from the longitudinal-optical phonon frequency. Photoluminescence (PL) was detected at 77 K after annealing at 300 deg. C. The peak energy for Zn_xCd_1-xS is large than that of CdS, as expected from the larger bandgap of the ally. The PL peak was red-shifted by annealing at higher temperature, which was attributed to defect formation during the annealing.