Eu-doped GaN and InGaN monolithically stacked full-color LEDs with a wide color gamut

Abstract

High-density micro light-emitting diode (μ-LED) arrays are key to next-generation ultrahigh-resolution displays. As a novel candidate, we report monolithic vertically stacked full-color LEDs consisting of Eu-doped GaN and InGaN quantum wells (QWs). Initially growing Eu-doped GaN, which shows a narrow linewidth ultra-stable red emission, allows vertically stacked growth of subsequent InGaN-QW-based blue/green LEDs while maintaining a high crystal quality. Electroluminescence from full-color LEDs has a remarkably wide color gamut, corresponding to 105.5% (147.0%) of the area with 91.2% (96.5%) coverage of the standards of Rec. 2020 (DCI-P3) at its maximum. The maximum luminance of the full-color LEDs reaches ~3100 cd/m².