论文标题
液体和机械剥落的WS $ _2 $单层的光物理比较
Photophysical comparison of liquid and mechanically exfoliated WS$_2$ monolayers
论文作者
论文摘要
半导体过渡金属二核苷（TMD）由于其强烈的激子效应而需要在光电设备中作为活性材料。它们可以通过液体去角质方法从其父母分层材料中剥落，以用于批量生产。但是，通过液相去角质制备的TMD的设备应用受其光致发光量子效率（PLQE）的限制。了解其实际设备开发的理由是至关重要的。在这里，我们通过系统地研究其光学和光物理特性，并与机械剥落（ME）WS2单层来评估单层富集液相去角质（LPE）WS $ _2 $分散质量。通过超快速泵送测量值获得了对激子动力学的深入了解。我们透露，LPE WS $ _2 $分散剂中的单层和少层之间的能源转移是其淬火PL的一个实质原因。此外，我们表明LPE WS $ _2 $有望建立具有出色光学质量的高性能光电设备。
Semiconducting transition metal dichalcogenides (TMDs) are desired as active materials in optoelectronic devices due to their strong excitonic effects. They can be exfoliated from their parent layered materials with low-cost and for mass production via a liquid exfoliation method. However, the device application of TMDs prepared by liquid phase exfoliation is limited by their poor photoluminescence quantum efficiencies (PLQE). It is crucial to understand the reason to low PLQE for their practical device development. Here we evaluate the quality of monolayer-enriched liquid phase exfoliated (LPE) WS$_2$ dispersions by systematically investigating their optical and photophysical properties and contrasting with mechanically exfoliated (ME) WS2 monolayers. An in-depth understanding of the exciton dynamics is gained with ultrafast pump-probe measurements. We reveal that the energy transfer between monolayer and few-layers in LPE WS$_2$ dispersions is a substantial reason for their quenched PL. In addition, we show that LPE WS$_2$ is promising to build high performance optoelectronic devices with excellent optical quality.
