Wide bandgap light-emitting devices materials and doping problems

The status of wide bandgap light-emitting devices based on ZnSe and on GaN based materials is reviewed. It can be noted that progress in this areas has been remarkably rapid in recent years, particularly in view of prior unsuccessful efforts over at least two or three decades. It is shown that recent progress can be attributed to a large extent to successful non-equilibrium doping both p-type ZnSe and GaN based materials.