Design and Photomodulation Performance of a UV-Driven Full GaN Integrated μLED and BJT Phototransistor

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.

Monolithic Integration of GaN-Based Transistors and Micro-LED

“…However, there are still some problems to be solved. The fabrication of BJT-integrated structures is complex, requiring a special growth process and micro-fabrication technical support, which greatly increases the manufacturing cost and reduces yield [ 39 ]. The device size and electrical characteristics of BJTs and LEDs need to be carefully designed and accurately matched to avoid the current mismatch and power loss.…”

Self-Powered Visible-Blind Ultraviolet Photodetector Based on Organic–Inorganic Hybrid Copper Halide [N(C2H5)4]2[Cu2Br4]

“…The demand for high-performance ultraviolet (UV) photodetectors has surged due to their critical role in diverse applications, including environmental monitoring, flame detection, and many others. − Commercial UV photodetectors have been dominated by vacuum photomultiplier tubes and UV-enhanced silicon photodiodes. The drawbacks of intricate fabrication processes, spectral selectivity, and high operating voltages limit their widespread adoption. − In recent years, ternary copper halides have emerged as promising candidates for UV photodetection due to their attractive attributes . These materials offer a unique combination of wide bandgaps suitable for UV light absorption, good environmental stability, and eco-friendliness. − All-inorganic ternary copper halides, represented by CsCu 2 I 3 and Cs 3 Cu 2 I 5 , have been extensively studied for UV photodetection, demonstrating a high responsivity, a high detectivity, and fast response speeds. , However, the inherent limitations in their structural diversity present challenges for further optimizing the UV photodetector performance.…”