HIGH-QUALITY ZNSE AND ZN(SE,S) PRODUCED BY LOW-TEMPERATURE PHYSICAL VAPOR TRANSPORT

High quality, large (25 mm in diameter) crystals of ZnSe and Zn(Se,S) were grown by low-temperature physical vapour transport method and cha racterized by various techniques, i.e. energy dispersive X-ray fluores cence spectrometry, double-crystal X-ray diffraction rocking curve FWH M, reflectivity measurements in the region of free exciton, electrical measurements and photoluminescence measurements for both low and high excitation densities. The measurement of the photoluminescence relate d to the neutral-donor-bound exciton revealed superlinear log(photolum inescence intensity) versus log(excitation intensity) dependence, whic h indicates stimulated emission phenomena.