Structural Design and Optoelectronic Performance Study of Heterojunction Light‐Emitting Transistor

Microlight‐emitting diodes (Micro‐LEDs) offer numerous unique advantages in terms of materials, devices, technologies, and process applications. To enable control of LEDs with low current input, a heterojunction integrated light‐emitting transistor (H‐LET) device is proposed. By vertically integrating a heterojunction bipolar transistor (HBT) with a Micro‐LED, a multifunctional optoelectronic device capable of light emission, modulation, and driving functions is achieved. The structure incorporates wide‐bandgap aluminum gallium nitride (AlGaN) material into the emission region, forming a heterojunction with GaN. This significantly enhances electron injection efficiency and current gain. Under low current drive, the H‐LET device achieves a current gain of up to 650. This results in superior current regulation and high‐frequency response compared to homojunction light‐emitting transistors. The H‐LET shows significant potential for applications in smart lighting, high‐definition displays, radio frequency systems, and high‐speed communication.