GaN can be used to make several types of devices; the primary GaN devices are LEDs, laser diodes, power electronics, and RF devices.
GaN is ideal for LEDs because of the direct bandgap of 3.4 eV which is in the near UV spectrum. GaN can be alloyed with InN and AlN, which have bandgaps of 0.7 eV and 6.2 eV, respectively. Therefore, this material systems can theoretically span a large energy spectrum for light emitting device. In actual practice, the efficiency is highest for blue InGaN devices and decreases for high indium content InGaN or for AlGaN emitters. The near UV and blue spectrum is optimal for making white emitters with phosphors, and this technology has been responsible for the remarkable efficiency gains in lighting since the 1990s when LEDs have begun to replace traditional light sources.
Laser diodes, usually with blue emission, can be made using GaN. These devices are used for displays and some specialty biomedical, cutting, and scientific applications. Laser diodes can also be used for making white light emitting devices with phosphors. Compared to LEDs, laser diode white light can achieve a very high power density and high directionality.
For power electronics, GaN-based devices can achieve high switching speeds, high power density, and low energy losses resulting in more efficient, smaller, and lighter power conversion products. There are numerous applications for GaN-based power electronics including electric vehicles, solar and wind energy inverters, industrial motor controllers, data centers, and consumer electronics.
GaN-based RF devices possess many of the same advantages of GaN power electronics, and additionally can access higher frequency than traditional semiconductors. RF devices are used for industrial heating, radar, and telecommunications. GaN is especially advantageous for high power density such as for cellular base stations.