GaN transistors are suitable for high frequency, high voltage, high temperature and high efficiency applications. GaN is efficient at transferring current, and this ultimately means that less energy is lost to heat. 
GaN High-electron-mobility transistor (HEMT)s have been offered commercially since 2006, and have found immediate use in various wireless infrastructure applications due to their high efficiency and high voltage operation. A second generation of devices with shorter gate lengths will address higher frequency telecom and aerospace applications.
GaN-based metal–oxide–semiconductor field-effect transistor (MOSFET) and metal–semiconductor field-effect transistor (MESFET) transistors also offer advantages including lower loss in high power electronics, especially in automotive and electric car applications. Since 2008 these can be formed on a silicon substrate. High-voltage (800 V) Schottky barrier diodes (SBDs) have also been made.
The higher efficiency and high power density of integrated GaN power ICs allows them to reduce the size, weight and component count of applications including mobile and laptop chargers, consumer electronics, computing equipment and electric vehicles.
GaN-based electronics (not pure GaN) have the potential to drastically cut energy consumption, not only in consumer applications but even for power transmission utilities.
Unlike silicon transistors which switch off due to power surges, GaN transistors are typically depletion mode devices (i.e. on / resistive when the gate-source voltage is zero). Several methods have been proposed to reach normally-off (or E-mode) operation, which is necessary for use in power electronics:
* the implantation of fluorine ions under the gate (the negative charge of the F-ions favors the depletion of the channel)
* the use of a MIS-type gate stack, with recess of the AlGaN
* the integration of a cascaded pair constituted by a normally-on GaN transistor and a low voltage silicon MOSFET
* the use of a p-type layer on top of the AlGaN/GaN heterojunction