Surface‐Plasmon‐Coupled Blue InGaN/GaN Micro‐LEDs with Oxide–Metal–Oxide Capping Layer Compatible to Chip Fabrication Process

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.