Electron and hole-related luminescence processes in Gate Injection Transistors

This paper reports an extensive investigation of the luminescence processes in GaN-based gate injection transistors (GITs). The results of the analysis indicate that: (i) GITs operating in on-state conditions can emit a weak luminescence signal; (ii) for moderate gate voltage levels, luminescence is originated at the edge of the gate toward the drain side, due to hot electrons accelerated by the high gate-drain electric field; (iii) for higher gate voltage levels, luminescence is originated in the region between the gate and the source of the devices, due to the recombination of the holes injected from the gate and the electrons present in the channel. Results obtained by means of electrical and optical measurements are compared throughout the paper to support the interpretation of the measurement results.