Current approaches to p n junctions in wider band gap II–VI semiconductors

Long-standing problems to make junctions in wider band gap semiconductors, especially II–VIs, are being restudied today by new low-temperature epitaxial growth methods, which may lead to current-injecting devices suited to light emission. This paper reviews various approaches briefly, with particular emphasis on heterojunctions and methods to control dopants. A few of the many possible heterojunctions are favored by small offset barriers, but are not without other problems. New dopants, besides the much-studied Li, are being introduced in new ways, in the effort to attain reproducibility and stability.