The effect of temperature on the exciton absorption of copper chloride and copper bromide nanocrystals in potassium-aluminum-borate glass

The absorption spectra of nanosized crystals of copper (I) halides distributed in the potassium-aluminum borate glass system were investigated in the region of the exciton absorption band in the temperature range from 20 to 300°C. The temperature dependences of the exciton absorption band of CuHal (Hal = Cl, Br) nanocrystals, which were obtained upon the heating and cooling of the sample, have a form of hysteresis. The melting (140–240°C) and crystallization (35–105°C) temperatures of copper (I) halide nanocrystals contained in the potassium-aluminum borate glass were determined by the optical spectroscopy method.