Photoluminescence in powdered and bulk glassy GeSe2

Abstract Fatigue of photoluminescence (PL) at 77 K in GeSe2 powder obtained by grinding glassy samples has been observed. The intensity decreases by ∼80% during 5 × 103 s. The peak positions of the PL spectra and their halfwidths for the powdered and bulk glassy GeSe2 coincide and have the values E p = 1.07 eV and Δ = 0.37 eV respectively. The temperature dependence of E p and Δ as well as the PL-decay rate in the range 77-250 K is also reported. The results are interpreted as recombination of tightly bound charge pairs in Coulomb centres whose fields are modified by shallow traps.