Monolithically integrated voltage-controlled MOSFET-LED device based on a GaN-on-silicon LED epitaxial wafer.

We report a novel monolithically integrated voltage-controlled metal-oxide-semiconductor field effect transistor (MOSFET)-LED device based on a GaN-on-silicon LED epitaxial wafer. An N-channel enhancement mode MOSFET and an InGaN/GaN multiple-quantum-well (MQW) thin-film LED featured with a suspended membrane are in series connection to constitute the monolithically integrated device without external metal interconnection. A recessed gate structure and AlGaN channel are innovatively adopted to realize an enhancement mode transistor. The fabrication of the MOSFET-LED includes no additional ion implantation or epitaxial growth compared with that of a common MQW LED, which greatly simplifies the device structure and production processes. The measured turn-on voltage of the LED is approximately 4 V, and the threshold voltage of the MOSFET is extrapolated as 5.2 V. The results demonstrate relatively good dimming and switching capacities of the integrated MOSFET-LED. This integration scheme also has potential to achieve a large-scale optoelectronic integrated circuit.