Theory of Semiconducting Superlattices and Microstructures

This final report of work summarizes the theoretical development of Semiconducting Superlattices and Microstructures. These include The first theory of Hjalmarson-Frenkel core excitons in superlattices, and applied it to strained-layer systems. This theory will be useful in characterizing phenomena in such superlattices, using synchrotron radiation. A unified theory of dopants in II-VI materials, with emphasis on ZnSe and candidates for blue-green lasers. This explains why Ga is no longer an effective dopant in Znl-xMnxSe for 0.1, with a theory that also provides a natural explanation of why ZnTe is almost unique among the II-VI semiconductors in that it is naturally p-type. This work provides, a theoretical framework for viewing and understanding the recent successes at 3M by Haas et al. in obtaining blue emission from ZnSe. It also provides strong evidence against the thirty-year-old explanation that self- compensation is responsible for the inability to make a p-n junction in II-VI semiconductors. A general theory of substitutional impurities in superlattices that predicts anomalous changes of dopant character with layer thicknesses, and establishes an intellectual framework for understanding the properties of impurities in superlattices. Superlattices, Bjalmarson-Frenkel Theory, Deep level theory, Mobius transforms, Amorphus silicon, ZnSe, Gap, Theory of dopants, Ti Tc Superconductors.