Inhibited nonradiative decay at all exciton densities in monolayer semiconductors

doi:10.1126/science.abi9193

GSTDTAP > 气候变化

DOI	10.1126/science.abi9193
	Inhibited nonradiative decay at all exciton densities in monolayer semiconductors
	Hyungjin Kim; Shiekh Zia Uddin; Naoki Higashitarumizu; Eran Rabani; Ali Javey
	2021-07-23
发表期刊	Science
出版年	2021
英文摘要	The photoluminescence quantum yield in monolayer transition metal dichalcogenides generally drops at high emission intensities because the excitons undergo nonradiative annihilation. Kim et al. show that this process is resonantly amplified in these materials by van Hove singularities in their joint density of states. However, application of small mechanical strains (∼0.5%) shifted the van Hove singularities and suppressed the nonradiative processes. Near-unity photoluminescence quantum yield at high exciton densities was seen in exfoliated monolayers of molybdenum sulfide, tungsten sulfide, and tungsten selenide, as well as centimeter-scale tungsten sulfide monolayers grown by chemical vapor deposition. Science , abi9193, this issue p. [448][1] 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. [1]: /lookup/doi/10.1126/science.abi9193
领域	气候变化 ; 资源环境
URL	查看原文
引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/334499
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Hyungjin Kim,Shiekh Zia Uddin,Naoki Higashitarumizu,et al. Inhibited nonradiative decay at all exciton densities in monolayer semiconductors[J]. Science,2021.
APA	Hyungjin Kim,Shiekh Zia Uddin,Naoki Higashitarumizu,Eran Rabani,&Ali Javey.(2021).Inhibited nonradiative decay at all exciton densities in monolayer semiconductors.Science.
MLA	Hyungjin Kim,et al."Inhibited nonradiative decay at all exciton densities in monolayer semiconductors".Science (2021).