STUDIES ON ZN-DOPED IN0.5GA0.5P LAYERS GROWN BY LIQUID-PHASE EPITAXY

Zn-doped In0.5Ga0.5P epilayers grown on semi-insulating (1 0 0) GaAs s ubstrates by liquid phase epitaxy (LPE) technique have been investigat ed using photoluminescence (PL) measurements from 17 K to 300 K. Trans itions involving accepters are identified and the ionization energy of Zn ranges from 45 meV to 31 meV as the concentration is increased fro m 1.5 X 10(17) to 3.4 X 10(19) cm(-3) at 17 K. The Zn related band shi fts towards higher energy with increasing hole concentration such that the quasi-Fermi energy level moves towards a higher energy with the i mpurity band merging with the valence band accompanied by a decrease i n the ionization energy of Zn. The calculated quasi-Fermi energy level s are in good agreement with the maxima of the observed PL peaks. (C) 1997 Elsevier Science Ltd.