A Monolithically Integrated GaN-Based Light Emitting Transistor with a High On/Off Ratio and Low Gate Leakage Current

This study presents a trench structured gallium nitride (GaN)-based light emitting transistor (LET) that integrates the functionalities of both a transistor and a light emitting diode into a single compact unit. Utilizing the superior material properties of GaN, these items surpass the performance of their silicon- or organic-based counterparts. However, due to polarization effects caused by the wurtzite crystal structure of GaN, the LET operates in depletion mode (D-mode). A metal-insulator-semiconductor gate was employed in the deep trench to mitigate prevalent issues such as poor gate controllability and high off-current in GaN-based devices. This work outlines the integrated device concept, operational mechanism, and fabrication process details and discusses the results of the characteristic assessment. The epitaxial wafer structure was optimized to enhance light emission, yielding a device capable of switching with an on/off ratio of approximately 10⁷ and emitting visible blue light through a multi-quantum well layer, fabricated using state-of-the-art semiconductor fabrication technology.