GaAsGaP Heterojunctions

GaAsGaP n–n, n–p, and p–n heterojunctions were fabricated by growing GaAs onto GaP substrates using HCl as the transport agent in an open‐tube system. It is found that the conduction band is continuous at the interface. This is in contrast to reported discontinuities of 0.65 and 0.22 eV. A high concentration of interface states is present in such junctions as evidenced by the frequency dependence of capacitance, and the I–U characteristics. Photocurrent response is as expected in n(GaAs)–p(GaP) heterojunctions, but a modulation effect was observed in p(GaAs)–n(GaP) junctions. This effect is not well understood.