Photoluminescence study of ZnSe single crystals grown by solidhyphen;phase recrystallization

摘要

We investigate through lowhyphen;temperature photoluminescence (PL) and selective photoluminescence (SPL) spectroscopies, ZnSe single crystals grown by solidhyphen;phase recrystallization. The PL spectra are dominated by the sohyphen;calledI1deepexcitonic line, a neutralndash;acceptor boundndash;exciton lineI1, the freehyphen;exciton emission FX, and then=2 excited state of FX. We identify the main residual impurities. Donorndash;acceptor pair bands are hardly detected. A major characteristic of these samples is the quasiabsence of any Cuhyphen;related deep emission which generally plagues the PL spectra of bulk ZnSe. Consequently,I1deepis ascribed to an exciton bound to Znhyphen;vacancies related acceptors. Our results indicate that these ZnSe samples are of high quality and that solidhyphen;phase recrystallization is a promising technique to prepare ZnSe epitaxial substrates. copy;1996 American Institute of Physics.