Surface‐Plasmon‐Coupled Blue InGaN/GaN Micro‐LEDs with Oxide–Metal–Oxide Capping Layer Compatible to Chip Fabrication Process
Pil‐Kyu Jang, Lee‐Woon Jang, Ohbin Kwon, Yeong‐Hoon Cho, Sangbum Kim, Sang‐Ik Lee, Seungjae Baek, Jiwon Park, Myeongjun Choi, Jaeseung Kim, Taehwan Kim, Sung‐Un Kim, Min‐Seok Lee, Yong‐Ho Ra, Ki Hoon Nam, Seung Min Kwak, Alexander Y. Polyakov, In‐Hwan LeeABSTRACT
Blue InGaN/GaN micro‐light‐emitting diodes are promising for next‐generation displays, but their efficiency severely diminishes at dimensions below ∼5 µm due to dominant sidewall‐induced non‐radiative recombination. To overcome this fundamental limitation, we propose a multifunctional oxide‐metal‐oxide (OMO) strategy to simultaneously passivate sidewall defects and introduce a highly efficient radiative recombination pathway via localized surface plasmon (LSP)‐exciton coupling. This OMO configuration integrates conformal Al 2 O 3 layers for effective surface passivation with thermally dewetted Ag nanoparticles, which serve as plasmonic centers. By precisely aligning the LSP resonance to the blue emission wavelength (∼450 nm), the OMO‐integrated 4 × 4 µm 2 devices exhibit a 61% enhancement in micro‐photoluminescence and a further 27% increase in external quantum efficiency compared with atomic‐layer‐deposited Al 2 O 3 references. These results suggest that the plasmonic OMO sidewall architecture is a wafer‐scale process‐compatible and potentially scalable route toward high‐performance, ultra‐small micro‐LED display pixels for future display applications.