JOURNAL OF THE KOREAN PHYSICAL SOCIETY, v.50, no.3, pp.858 - 861
Abstract
We report a systematic investigation of band-edge photoluminescence of the II-VI wide band-gap semiconductor Zn1-xBexSe for a series of Be compositions (0 < x < 0.4). The specimens investigated were in the form of thin films fabricated by using molecular beam epitaxy (MBE). The near band-edge emissions of free excitons (designated as FX) were systematically investigated as a function of temperature and of alloy composition. From the temperature dependence of the free exciton peak, the Varshni temperature parameters α and β were found to increase with increasing Be concentration x. From the temperature dependence of the FWHM of the free exciton FX emission line, the broadening factors Γ(T) were determined from a fit to the data. Furthermore, the activation energies of thermal quenching for the EA peak were obtained from the temperature dependence of the free exciton peaks, and were found to decrease with increasing Be concentration.