Donor-acceptor pair transitions in CuInS2

Abstract
We have studied the cathodoluminescence (edge emission) of single crystals of CuInS2 obtained by iodine chemical transport. Emission intensity as a function of excitation, temperature, and time [time resolved spectroscopy] allow us to reveal donor‐acceptor transitions. By fitting the TRS spectra, we calculate the ionization energy of the impurities involved: EA,D≃45 meV, ED,A ≃95 meV, as well as the maximum transition probability: WMAX≃108 s−1.