Photoassisted molecular beam epitaxy (PAMBE), in which the substrate is illuminated during film growth, is being employed in a new approach to controlled substitutional doping of II–VI compound semiconductors. Substitutional doping of these materials has been a long standing problem which has severely limited their applications potential. The PAMBE technique gives rise to dramatic changes in the electrical properties of as-grown epilayers. 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 rocking curve data indicate that the doped epilayers are of high structural quality. Successful n-type doping of CdMnTe, a dilute magnetic semiconductor, with indium has also been achieved. Most recently, the photoassisted growth technique has been employed to prepare doped CdMnTe-CdTe quantum well structures and superlattices. In addition, HgCdTe films which exhibit excellent optical and electrical properties as well as exceptional structural perfection have been grown by the PAMBE technique.