Radiative centers in layered semiconductor GaS doped with Zn

The radiative recombination mechanisms of the Zn-doped GaS have been investigated using photoluminescence (PL) measurements. In these undoped and Zn-doped samples, the five emission bands at 2.570, 2.555, 2.534, 2.521, and 2.480 eV are related to the indirect band exciton with phonon emission. The PL spectrum (at 77 K) related to the impurity level is dominated by the new emission band at 1.85 eV. The temperature dependences of the PL intensity, peak energy, and full-width at half-maximum are characterized by the recombination mechanism of the configurational coordinate model. It is found that the1.85 eV emission band is related to the acceptor-vacancy complex center.