Design and Photomodulation Performance of a UV-Driven Full GaN Integrated μLED and BJT Phototransistor
Wenjuan Su, Haonan Wang, Zhenyou Zou, Changjing Chai, Shuchen Weng, Jinyu Ye, Jie Sun, Qun Yan, Xiongtu Zhou, Chaoxing Wu, Yongai Zhang
Abstract
A vertical integration of indium gallium nitride/gallium nitride (InGaN/GaN)-based microlight-emitting diode (μLED) and GaN ultraviolet bipolar junction transistor (BJT) phototransistor (UVPT), based on the same GaN material and process platform (UVPT-μLED), was proposed. The integrated device is a novel integrated device with light-emitting, detecting, sensing, driving and regulating functions. It can be used as a receiver and transmitter. The light-emission effect of the μLED on UVPT can be regulated by changing the power of an external light. Optical-electrical-optical conversion was conducted with Silvaco TCAD software. Electro-optic modulation characteristics and optical power amplification were attained through a Silvaco TCAD simulation. By optimization of the size and concentration of the device epitaxial, the current gain of the optimized device reaches a maximum of 240. The UVPT-μLED device shows a strong response to small-power light and a stable response to high-power light. The UVPT-μLED chip with a high switching ratio was successfully prepared and used to verify the feasibility of the UVPT-μLED device. The proposed monolithic integrated device not only can be used for traditional displays but also shows great potential in intelligent displays, such as human–computer interactive systems, on-chip optical interconnects, photonic chips and visible-light communications.