Laser-induced donor diffusion in ZnTe

We report the first experiments on laser-induced donor diffusion in ZnTe. Aluminum, chlorine, and indium are incorporated in ZnTe single crystals from a metal layer at the crystal surface, or from a gas atmosphere during millisecond laser heating. Broad luminescence bands are observed on the irradiated areas of the crystal, which in the case of Cl give a bright and efficient photoluminescence even at room temperature. Our results indicate that a part of the dopant atoms has formed various complexes. The high-energy part of the spectra shows that Li and Ag atoms have been liberated during the laser irradiation from precipitates. The appearance of two lines at 2.361 and 2.357 eV after the irradiation can be explained by the decay of excitons bound to radiation-induced defects, or by the liberation of Au and a second deep acceptor from precipitates.