Jin Yu is a physics graduate who joined KAUST in July 2021 from Nankai University (NKU), China. Before joining KAUST, Jin worked as an intern at Wake Forest University (WFU), North Carolina, U.S. After completing his studies at WFU, Jin served as a volunteer high school teacher at China Volunteer Association for almost a year.
The paper reports the investigation of the optical properties of InGaN-based red LED structure with a blue pre-well by measuring the excitation energy and temperature dependent photoluminescence (PL) spectra. The deep localization of quasi-QD structures suppresses efficiently the escape of carriers and then enhances the emission in the red, which is the reason for strong emission intensity. The variation of internal quantum efficiency with excitation intensities indicates the better crystal quality of blue pre-well and the occurrence of defects in the red-emitting structures. The experimental results will provide a useful guidance to fabricate a longer wavelength InGaN-based optoelectronic devices with high-quantum efficiency. the luminescence improvement of InGaN-based red LEDs by introducing a micro-hole array. This technique provides the improvement of the internal quantum efficiency and light extraction efficiency. The InGaN-based red LEDs are very attractive for next-generation micro-LED display, because the material is a family of blue and green LEDs.
As one of the most cited articles from Saudi Arabia published across the entire IOP Publishing journal portfolio in 2020, using citations recorded in Web of Science “Demonstration of low forward voltage InGaN-based red LEDs” D. Iida, Z. Zhuang, P. Kirilenko, M. Velazquez-Rizo, and K. Ohkawa, Applied Physics Express 13, 031001 (2020).
The paper reports InGaN-based RGB micro-LED arrays that comprise every single µLED in the dimension of 17 × 17 µm2. We obtained the output power density of the InGaN-based red µLEDs as 1.76 mW/mm2, which was estimated to be higher than that of 20 × 20 µm2 AlInGaP red µLEDs (~630 nm). The result reveals a great potential for the InGaN materials to be used in full-color micro-displays.
The paper reports an atomistic origin of composition pulling effect in all GaN-based ternary alloy was clarified from the the geometric configurations using first-principles calculations. We found that the most stable configuration involves two B, In, or Al atoms occupying Ga sites in wurtzite GaN along the c-axis which is the typical epitaxial growth direction.


Energy is an indispensable part of our lives. We are challenging energy-saving novel light emitters and clean-energy generation systems at Energy Conversion Devices and Materials (ECO Devices) Laboratory at KAUST. The former is based on MOCVD technology, material science, and device technology. The latter is the nitride photocatalyst invented by Ohkawa.