Highly radiative emission of room temperature-localized excitons enabled by charge-neutralized 0D quantum wells in 2D semiconductors.

Moon, Taeyoung; Lee, Hyeongwoo; Lee, Jihae; Oh, Dong Kyo; Choi, Soo Ho; Koo, Yeonjeong; Stevens, Christopher E; Cho, Hyunje et al. · Sci Adv · 2026

basic_science · Level V

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Abstract

Nondiffusing localized excitons (X<sub>L</sub>) in two-dimensional semiconductors present a robust platform for mediating light-matter interactions, with potential applications in both photovoltaics and light-emitting devices. However, at room temperature, high thermal energy hinders X<sub>L</sub> formation, while excess charges diminish the quantum yield (QY) through nonradiative decay. Here, we present high-QY X<sub>L</sub> emission in ambient conditions by removing excess charges and inducing efficient exciton funneling into a Au nanohole. Specifically, by evaporating an H<sub>2</sub>O barrier between the n-type MoS<sub>2</sub> and the Au substrate, we induce a grounding effect on electrons. Dominantly populating excitons are then funneled and bound to the nanohole through the strain-induced zero-dimensional quantum well effect. We confirm the exciton confinement efficiency of ~98% using a drift-diffusion model, enabling bright X<sub>L</sub> emission at the nanoscale. Using tip-induced gigapascal-scale pressure, we control X<sub>L</sub> dynamics and QY in a reversible manner. Our approach provides an innovative strategy for X<sub>L</sub>-based nanophotonic devices.