After the research efforts of Pankove and co-workers had ended, work on GaN virtually ceased. In 1982 only a single paper was published on GaN. However, Isamu Akasaki and co-workers in Nagoya, Japan, refused to give up, and in 1989 they demonstrated the first true p-type doping and p-type conductivity in GaN. The stubborn Mg […]

The beginning of visible-spectrum LEDs dates back to the year 1962 when Holonyak and Bevacqua (1962) reported on the emission of coherent visible light from GaAsP junctions in the first volume of Applied Physics Letters. Although the emission of coherent light was only observed at low temperatures, the devices worked as LEDs and emitted visible […]

Prior to the 1950s, SiC and II-VI semiconductors had been well-known materials. Many II-VI semiconductors, e. g. ZnS and CdS, occur in nature. The very first LEDs had been made using SiC and there had been one publication by Destriau (1936) reporting LEDs made of zincblende (ZnS). The era of III-V compound semiconductors started in […]

Starting early in the twentieth century, light emission from a solid-state material, caused by an electrical power source, has been reported: a phenomenon termed electroluminescence. Because electroluminescence can occur at room temperature, it is fundamentally different from incandescence (or heat glow), which is the visible electromagnetic radiation emitted by a material heated to high temperatures, […]

E. Fred Schubert During the last four decades, technical progress in the field of light-emitting diodes (LEDs) has been breathtaking. State-of-the art LEDs are small, rugged, reliable, bright, and efficient. At this time, the success story of LEDs still is in full progress. Great technological advances are continuously being made and, as a result, LEDs […]