TEMPERATURE-RESOLVED PHOTOLUMINESCENCE STUDIES OF CUINSE2

Photoluminescence (PL) studies of CuInSe2 powders, as function of temperature, have been performed. At low temperatures the k-band, centered at hv(max) approximate to 0.92 eV dominates the PL intensity. Increasing the temperature leads to rapid quenching of the intensity k-band and thus the j-band with hv(max) approximate to 0.95 eV appears. The calculated activation energies of temperature quenching for j-band lie near 20 meV value and seems to have a tendency to increase with an increasing of selenium vapour pressure. The phonon-broadening analysis of the j-band indicates, that the radiative recombination is accompanied by the emission of 3.4 phonons with mean energy of 10.23 meV. The j-band is concluded to be associated with donor-acceptor recombination from donor level E(D) = 60 meV to acceptor level E(A) = 20 meV.