ABSTRACT
The photoluminescence (PL) spectra of AgInSe2 single crystals are measured in the temperature range of 4.2 to 300 K. We have resolved at 4.2 K the two components corresponding to the ground state (n=1) at 1.2418 eV and the first excited state (n=2) at 1.2453 eV of the direct exciton series. Using a hydrogen-like approximation for free excitons we obtained the exciton binding energy 4.7 meV and direct energy gap 1.2465 eV at 4.2 K. The other defect-related luminescence bands at 1.238, 1.207, 1.194 and 1.154 eV have been also observed.
