Abstract
Most optoelectronic devices operate at high photocarrier densities, where all semiconductors suffer from enhanced nonradiative recombination. Nonradiative processes proportionately reduce photoluminescence (PL) quantum yield (QY), a performance metric that directly dictates the maximum device efficiency. Although transition metal dichalcogenide (TMDC) monolayers exhibit near-unity PL QY at low exciton densities, nonradiative exciton-exciton annihilation (EEA) enhanced by van-Hove singularity (VHS) rapidly degrades their PL QY at high exciton densities and limits their utility in practical applications. Here, by applying small mechanical strain (less than 1%), we circumvented VHS resonance and markedly suppressed EEA in monolayer TMDCs, resulting in near-unity PL QY at all exciton densities despite the presence of a high native defect density. Our findings can enable light-emitting devices that retain high efficiency at all brightness levels.
Original language | English |
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Pages (from-to) | 448-452 |
Number of pages | 5 |
Journal | Science |
Volume | 373 |
Issue number | 6553 |
DOIs | |
Publication status | Published - 2021 Jul 23 |
Bibliographical note
Publisher Copyright:© 2021 American Association for the Advancement of Science. All rights reserved.
All Science Journal Classification (ASJC) codes
- General