Abstract:
A study was made of time and spectral-time characteristics of the radiation emitted from pure and doped cadmium sulfide subjected to high rates of excitation (1027 – 1028 cm–3·sec–1) at 300 °K. The radiative transition times were determined for various recombination channels: τex = (11–12)×10–9 sec for the exciton mechanism accompanied by the emission of one or two phonons; τib = 6×10–9 sec for the interband mechanism (when the nonequilibrium carrier density was Δn = 1×1018 cm–3); τimp = (1–3)×10–9 sec for the mechanism involving shallow impurities. The interband radiative recombination coefficient Bib = 1.55×10–10 cm3/sec (Δn ~1018 cm–3), the critical density for the Mott transition ncr = 6.5 ×1017 cm–3, and the coefficient representing the binding of carriers into excitons γex ≈ 10–8 cm3/sec were determined.