Controlled substitutional doping of CdTe thin films grown by photoassisted molecular-beam epitaxy

Abstract

We report the successful substitutional doping of CdTe films grown by a new technique: photoassisted molecular-beam epitaxy. This new growth technique gives rise to dramatic changes in the electrical properties of as-grown epilayers, as determined by variable-temperature Hall-effect measurements. In particular, highly conducting n-type and p-type CdTe films have been grown using indium and antimony as n-type and p-type dopants, respectively. Double-crystal x-ray diffraction rocking curve data indicate that the doped epilayers are of high structural quality. Using the photoassisted molecular-beam epitaxy technique, double-layer thin-film CdTe p–n junction diodes have been successfully fabricated for the first time. The application of this new film growth technique to control the electrical properties of another II–VI material has also been demonstrated by the successful n-type doping of CdMnTe epilayers with indium.