Electrical properties of p-type and n-type ZnSeZnTe strained-layer

ZnSe and ZnTe semiconducting materials are highly promising candidates for the fabrication of short-wavelength light-emitting devices. We have grown ZnSeZnTe strained-layer superlattices (SLSs) on InP substrates by molecular beam epitaxy. In addition to undoped SLSs, two kinds of modulation doped SLS samples were prepared in this study, the first with Ga-doped ZnSe layers and undoped ZnTe layers, and the second with undoped ZnSe layers and Sb-doped ZnTe layers. Van der Pauw measurements of the SLS samples at room temperature showed that their electrical properties can be controlled by using the modulation doping technique. The undoped sample and the Ga-doped sample exhibited n-type conduction, whereas p-type conduction was observed for the Sb-doped sample. Interdiffusion profiles of dopants were measured by secondary ion mass spectroscopy, and significant Ga redistribution was observed. Finally, we have fabricated pn junctions from ZnSeZnTe SLSs, and measured their current-voltage characteristics.