Vapor growth of high quality ZnSe single crystal

Zn(NH₄)₃Cl₅ as a novel transport agent with high thermo-stability was used to grow ZnSe single crystal from ZnSe polycrystals by chemical vapor transport method. The Zn_1+0.031Se crystal of 9 mm diameter and 25 mm length was obtained. The growth temperature is 898-915°C and the temperature gradient at growth interface is less than 1.5 K·cm¹. The orientation and crystal quality of as-grown crystal were investigated by RO-XRD. FWHM value of the RO-XRD patterns of ZnSe(111) face is 24 s. The photoluminescence spectrum of the as-grown crystal, which locates at blue region, consists of a band-to-band transition peak (418 nm) and F_x emission peak (439 nm). No donor-acceptor pair emission and self-activated luminescence band are detected in low energy region. The average etch pit density is about (5-7)×l0⁴ cm^-2. The absorption edge is very sharp and located at about 465 nm.