Wide-Bandgap Semiconductors: The Third-Generation Materials for Power and RF
{{Wide-bandgap semiconductors}} have bandgaps above ~2 eV (versus {{silicon}}'s ~1.1 eV), letting them operate at higher voltages, temperatures, and frequencies. Examples include {{silicon carbide}}, {{gallium nitride}}, diamond, and gallium oxide; SiC and GaN dominate today's power and RF electronics.
A wide-bandgap semiconductor (WBG) is a material whose bandgap substantially exceeds that of conventional semiconductors, generally above about 2 eV compared with silicon's ~1.1 eV and gallium arsenide's ~1.4 eV. WBG materials are often called "third-generation" semiconductors (silicon being first-generation and GaAs/InP second-generation). The wider gap has concrete engineering payoffs. Because more energy is needed to excite electrons across the gap, devices keep working at much higher temperatures (on the order of 300 C versus silicon's ~100-150 C). The materials also withstand electric fields roughly ten times stronger before breakdown, so a device can block the same voltage in a thinner, lower-resistance structure. Together with higher carrier saturation velocity, this enables faster switching, higher power density, and lower conversion losses. The main WBG materials are Silicon Carbide (SiC): The Wide-Bandgap Semiconductor for Power Electronics (~3.2 eV), Gallium Nitride (GaN): The Wide-Bandgap Semiconductor Behind Blue LEDs and Fast Chargers (~3.4 eV), diamond (~5.5 eV), aluminum nitride (~6 eV), and the emerging gallium oxide (~4.8 eV). SiC and GaN are by far the most commercially important, powering EV inverters, solar and grid converters, fast chargers, and RF amplifiers. WBG adoption is a major reason power conversion has become smaller and more efficient over the past decade. See No Single Successor to Silicon: The Heterogeneous Future of Chip Materials for the broader picture.