Ge-doped InxGa1−xAs p−n junctions

The amphoteric properties of Ge in the In_xGa_1?xAscrystals grown by liquid-phase epitaxy are reported. It was found from the Hall measurements that when x < 0·1, the Ge-doped In_xGa_1?xAs was p-type, and when x > 0.1,it was n-type . At the vicinity of x = 0.1, therefore, the In_xGa_1?xAs p?n junction could be made by one growth process. The electrical and photoelectric characteristics of that junction were investigated. The distribution of Ge concentration at the p?n junction, which was obtained from the C-V characteristics, depended on the doping concentrations of Ge. This dependence can be interpreted by analyzing a modified Longini-Green equation. The spectral responses of both photovoltaic effect and electroluminescence showed that in In_0.1Ga_0.9As, Ge atoms gave rise to a heavy compensation effect, and introduced a conduction band tail of states and two kinds of acceptor levels located ～ 20and～ 100meV above the valence band edge.