A donor-acceptor pair broad band emission in AgGaS2

We interpret in this paper a broad band emission of silver thiogallate (AgGaS₂) peaked at 1.642 eV with a width of 395 meV. We show that the recombination kinetics are governed by donor-acceptor processes, with the band shape dominated by vibronic interaction. A theoretical calculation of the time-resolved spectra built with the parameters of donor-acceptor transitions gives good agreement with the experimental spectra.