Strain‐Driven Monolithic Nanowire LEDs for Pixel‐Level Color Control in High‐Resolution Displays

ABSTRACT The advent of next‐generation augmented reality (AR) and virtual reality (VR) systems has driven a significant demand for ultra‐high‐resolution micro‐displays with tunable color emission, yet achieving full‐color emission on a single GaN‐based wafer remains a challenge. Nanowire structures offer a superior solution to this limitation by enabling localized strain engineering to precisely tune emission colors directly from high‐quality planar epilayers. In this work, we systematically investigate strain‐induced tuning in green nanowire LED arrays fabricated via a top‐down ICP etching process. Progressively reducing nanowire diameters from 2 µm to 100 nm resulted in a 16 nm continuous spectral blueshift, successfully realizing monolithic color tuning from green (∼504 nm) to blue (∼488 nm) on a single wafer. The devices exhibited enhanced wavelength stability and consistently low reverse leakage currents, confirming fabrication reliability. To uncover the underlying physics, 3D numerical simulations were performed, revealing a “Core–Shell” relaxation mechanism. As the diameter decreases, a larger proportion of relaxed shell suppresses the internal piezoelectric field and flattens the energy bands. This fundamental physical mechanism directly drives the observed size‐dependent color control. Ultimately, these findings offer a controllable and scalable pathway for high‐performance, multi‐color monolithic micro‐display integration.