BARRIER HEIGHTS AND CONTACT PROPERTIES OF N-TYPE ZNSE CRYSTALS

Barrier-height measurements performed on ultrahigh-vacuum-cleaved and on chemically etched ZnSe crystals have shown that for most metals the barrier height increases linearly with its electronegativity. The highly reactive metals Mg, Ca, and Ba were found to be an exception, showing a decrease in barrier height with increasing electronegativity. Aluminum, when diffused into ZnSe from a film deposited onto a vacuum-cleaved surface, was found to produce a low-resistivity surface layer, followed by a highly compensated region in the crystal. This effect is suggested to arise from copious generation of Zn vacancies at the Al-doped crystal surface, and their influx, ahead of the Al, into the crystal. © 1969 The American Institute of Physics.