PHOTOASSISTED MBE GROWTH OF II-VI FILMS AND SUPERLATTICES

Photoassisted molecular beam epitaxy (MBE), in which the substrate is illuminated during film growth, is being employed in a new approach fo r controlled substitutional doping and structural improvement of II-VI compound semiconductors. The photoassisted MBE technique gives rise t o dramatic changes in the electrical properties of as-grown epilayers. In particular, highly conducting n-type and p-type CdTe films have be en grown on CdTe substrates using indium and antimony as n-type and p- type dopants, respectively. Double-crystal X-ray rocking curve data in dicate that the doped epilayers are of high structural quality. We hav e also employed photo-assisted MBE to successfully prepare p-type and n-type modulation-doped HgCdTe films and superlattices on CdZnTe subst rates. Most recently, we have extended the photoassisted MBE technique to successfully grow ZnS films, along with ZnS/ZnSSe and ZnS/ZnCdS mu lti-quantum-well structures on GaP substrates. In this paper, we repor t details of the MBE growth experiments and describe the structural, o ptical, and electrical properties of the II-VI films and superlattices prepared by this technique.