Switching Behaviors of On-Chip Photon Source on AlGaN/GaN-on-Si Power HEMTs Platform

The switching behavior of on-chip photon sources, i.e., the p-doping-free Schottky-on-heterojunction light-emitting diodes (SoH-LEDs), which can be seamlessly integrated into the AlGaN/GaN-on-Si power high electron mobility transistors platform is investigated. It is demonstrated that the electroluminescence (EL) from an interdigital SoH-LED can be switched at least up to 10 MHz, fulfilling the requirement of most power switching circuits. In order to evaluate the EL switching limit of SoH-LEDs, a quantitative analysis of the dependence of junction current on operating frequency at different dc biases is performed based on S-parameter characteristics. At a criterion of junction-current/input-current to 50%, the cutoff frequency of an interdigital SoH-LED is obtained to be 210 MHz at a forward bias of 4 V. This letter proves that the SoH-LED is adequately fast for being employed as an on-chip synchronous photon source in GaN power switching applications.