Optical absorption and phase transitions in CuInSe2and CuInS2single crystals at high pressure

摘要

The optical absorption edge of CuInSe2and CuInS2single crystals was measured as a function of hydrostatic pressure up to 10 GPa. In both cases the direct energy gap increases linearly with pressure at the rate of 30 and 24 meVthinsp;GPaminus;1for CuInSe2and CuInS2, respectively. From changes in the lighthyphen;transmission characteristic of the samples under pressure, a structural firsthyphen;order irreversible transition was observed at 7.1 GPa for CuInSe2and 9.6 GPa for CuInS2. Also, a new metastable semiconducting phase was formed in pressurehyphen;quenched CuInS2samples.