GaN: from fundamentals to applications

The fundamental differences between GaN and SiC are reviewed, then the problems of doping GaN are explored. The range of energy band gaps obtainable with alloys of all the III-Nitrides extends from 1.9 to 6.2 eV. Finally, various applications of the III-Nitrides are described with emphasis on solar blind UV detectors, light-emitting and modulating devices, cold cathodes and, in more detail, a heterojunction bipolar transistor that uses a SiC base layer and operates above 500°C.