Heterojunctions which were grown by using liquid-phase epitaxy were investigated by using I-V and Io(T) measurements. It was shown that the injection of electrons across the hetero-interface was described well by a thermionic emission model which involved a barrier height that was strongly affected by p-type dopant diffusion. Heterojunction bipolar transistors with Schottky collectors were used as tools to measure the injection current in as-grown p+-In0.53Ga0.47As/n-InP diodes, and the results were compared with the predictions of the thermionic emission model. In this way, the relative diffusivities of the three p-type dopants in InP at 600C were evaluated. The results could be summarized by:

DBe/DMn ˜ 20, DMg/DBe ˜ 1

P.S.Whitney, J.C.Vicek, C.G.Fonstad: Journal of Applied Physics, 1987, 62[5], 1920-4