Xin-Liang Ye's scientific contributions

This study aims to improve the characteristics of AlGaInP-based micro light-emitting diodes (micro-LEDs) by utilizing three different passivation layers, including silicon dioxide (SiO $_{\text{2}}$ ), distributed Bragg reflector (DBR), and aluminum oxide (Al $_{\text{2}}$ O $_{\text{3}}$ ) grown by atomic layer deposition (ALD) in combination with DBR. In terms of transmittance and refractive indices, our proposed structure, constructed with ALD-grown Al $_{\text{2}}$ O $_{\text{3}}$ and a nine-layered DBR, exhibits significant improvements in all aspects compared to the traditional structure with a 3000 Å SiO $_{\text{2}}$ passivation layer. Additionally, the structure demonstrates a 124.28% increase in external quantum efficiency (EQE) compared to the LED constructed with a nine-layered DBR. This result indicates that the ALD growth of Al $_{\text{2}}$ O $_{\text{3}}$ effectively reduces sidewall losses, significantly impacting the improvement of micro-LEDs.

This study investigates the effects of TMAH treatment on 5 μm-sized GaN-based micro light-emitting diodes (LEDs). Compared with untreated GaN micro-LEDs, the optical output power and external quantum efficiency of TMAH treated micro-LEDs are significantly improved. These results can be attributed to the formation of microstructures on the sidewall of micro-LEDs through the TMAH treatment and the effective light reflection is therefore constructed. This research not only improves the characteristics of LEDs, but also paves the way for green and advanced optoelectronic devices.

The efficiency of AlGaInP micro light-emitting diodes (micro-LEDs) was far weaker than that of GaN-based micro-LEDs in structure and performance. Consequently, there was an urgent demand to enhance their efficiency. In this study, a citric acid treatment strategy is proposed to improve the efficiency of red micro-LEDs, and the etching uniformity of different concentrations was first confirmed. We optimized the concentration of citric acid to 1:1 and modulated the wet etching time at 0, 30, 60, 90, and 120 s to treat the sidewalls of devices. Under an injection current density of 68 nA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , the forward voltage (Vf) of micro-LEDs after soaking in citric acid ranged from 1.40 to 1.45 V. Compared with the sample operated at the forward voltage without citric acid sidewall treatment, AlGaInP micro-LEDs displayed significantly enhanced forward voltage. This indicates that citric acid effectively removed N-GaAs without damaging the electrical properties of the devices. Among all citric acid-treated micro-LEDs, the sample with a 60 s wet etching process showed the best improvement, with the light output power and external quantum efficiency (EQE) increased by 31.08% and 5.4%, respectively. Our proposed method to treat AlGaInP micro-LEDs presents promising opportunities for the future development of high-performance optoelectronics.