Photoluminescence and Raman spectroscopy of polycrystalline AgInTe2

We studied the photoluminescence characteristics of polycrystalline chalcopyrite AgInTe2. The spectra showed three bands. The first band has the maximum at 1.023 eV, and it has one LO-phonon replica with the energy of 25 meV. The second band has the maximum at 0.959 eV and two phonon replicas with the same LO-phonon energy. The third broad band has the maximum at 0.741 eV. The dependence of the spectra on the temperature and the excitation power were recorded. According to the observed j-shift and thermal quenching, the 0.959 eV band can be assigned to a donor–acceptor pair recombination with the activation energy of 35 meV. Room temperature unpolarised Raman spectrum revealed six peaks. The lines observed at 122, 140, 217, and 266 cm−1 are assigned to A1, E1, or B1, E+B2, and longitudinal optical E modes, respectively.