Ge-doped In xGa 1−xAs p− n junctions

Abstract

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.