Temperature dependence of biexciton luminescence in cubic ZnS single crystals

Temperature dependence of the excitonic and biexcitonic emissions in cubic ZnS single crystals has been studied by photoluminescence technique. We observed the very well-resolved excitonic and biexcitonic emissions from cubic ZnS single crystals with very low excitation density, in the tens-of-milliwatts-per-square-centimetre range. The kinetic energy contribution to the shift with temperature of the biexcitonic emission was determined showing a characteristic difference with the normal shift caused by the temperature-narrowed band gap.