Wide Gap II-VI Semiconductors

The future of the II-VIs, especially the wide bandgap compounds and their alloys, is crucially dependent on the creation and development of major new device applications. Hence the focus of this conference was on the potential of these compounds and alloys as blue light emitters and laser diodes. The role of low temperature epitaxial growth techniques in bringing about these advances in the wide bandgap II-VIs was also emphasized during the meeting, as was the importance and potential of heterostructures and superlattices for the fabrication of new device structures. The current status of the role of ZnSe and ZnS and its alloys was the subject of considerable interest and discussion, as were their rivals gallium nitride, silicon carbide and the frequency doublers involving the use of GaAs lasers with, for example, YAG or potassium niobate. These topics feature in two round table discussions which are reported in this volume, one on "Doping in II-VIs" and the other on "Practical Devices for Blue Emission". The overall view of the meeting was that considerable advances have been made in ZnSe in the last six to twelve months, not only in the achievement of conducting p-type material but also in the fabrication of blue emitting diodes albeit with poor quantum efficiency. The overall impression was one of confidence resulting from a better understanding of the problems of these materials and their potential solutions.