P-Type Conduction in ZnS Grown by Vapor Phase Epitaxy

Abstract
Low-resistivity p-type ZnS layers have been grown on GaAs substrates by vapor-phase epitaxy from a Zn-added ZnS powder source, using an open tube system under a NH3-added hydrogen flow. The simultaneous addition of NH3 and Zn has been shown to be essential for the appearance of p-type conduction. The room temperature Hall-effect measurement of a grown layer revealed the hole concentration to be 6×1018 cm-3 and the mobility to be 40 cm2/(V·s). The p-ZnS/n-GaAs heterojunction showed good rectifying behavior and exhibited an infrared emission, having a peak photon energy corresponding to the band gap energy of GaAs under forward bias.