CoolGaN™ Gallium Nitride HEMTs Infineon CoolGaN™ Gallium Nitride HEMTs offer excellent advantages, including ultimate efficiency, reliability, power density, and higher quality compared to silicon. CoolGaN transistors are built with the most reliable technology and designed for the highest efficiency and power density in switch mode power supplies. The devices work similarly to conventional silicon MOSFETs with enhancement mode gate drive bias using a p-GaN gate structure.