Red Ag-Based I–III–VI Quantum Dots as Competitive Alternatives to InP Emitters
Seong Min Park, Yuri Kim, Yubeen Kong, S. R. Ryu, Yang‐Hee Kim, Changhoon Lee, Beomgyu Kim, Kyoungwon Park, Heesun Yang
Abstract
Heavy metal-free I–III–VI quantum dots (QDs), particularly those incorporating Ag and Cu, are promising ecofriendly alternatives to Cd- and Pb-based QDs. Yet, achieving both high photoluminescence quantum yield (PL QY) and narrow emission in red-emissive I–III–VI QDs remains a significant challenge. Herein, we systematically synthesize red-emitting Ag-based ternary, quaternary, and quinary I–III–VI QDs via core size tuning, compositional engineering, and GaS x shelling. Optimizing the Se/S ratio and introducing Ga 3+ into the core yield Ag–In–Ga–S–Se (AIGSSe) QDs with an outstanding PL QY of 82% and a narrow bandwidth of 46 nm. These QDs surpass conventional Ag-based QDs in optical quality and outperform red InP QDs in light absorption and blue-to-QD color conversion efficiency. The AIGSSe QDs thus present a compelling alternative for next-generation QD display applications, offering a unique combination of high emissivity, narrow bandwidth, and strong absorption.