Enhanced interlayer neutral excitons and trions in trilayer van der Waals heterostructures
Enhanced interlayer neutral excitons and trions in trilayer van der Waals heterostructures
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DOI：
10.1038/s41699-018-0075-1
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发表时间：
2018-09-17
影响因子：
9.7
通讯作者：
Wong, Chee Wei
中科院分区：
文献类型：
--
作者：
Choi, Chanyeol;Huang, Jiahui;Wong, Chee Wei
垂直堆叠的货车德瓦耳斯异质结构构成了一个有前途的平台，提供定制的带对齐增强激子系统。在这里，我们报告的中性和带电的层间激子在三层WSe 2-MoSe 2-WSe 2货车德瓦耳斯异质结和它们的动力学观察。在三层中添加WSe 2层导致显着更高的光致发光量子产率和可调光谱共振相比，其双层异质结构在低温下。在光致发光量子产率的观察到的增强是由于显着更大的电子-空穴重叠和更高的光吸收的三层异质结构，通过第一性原理赝势计算的基础上自旋极化密度泛函理论的支持。我们进一步揭示了三层异质结层间中性激子和三重激子的温度和功率依赖性，以及时间分辨的光致发光。我们的研究阐明了利用第一性原理控制层间激子发光和设计原子异质结构的光电子学前景。
Vertically stacked van der Waals heterostructures constitute a promising platform for providing tailored band alignment with enhanced excitonic systems. Here, we report observations of neutral and charged interlayer excitons in trilayer WSe2-MoSe2-WSe2 van der Waals heterostructures and their dynamics. The addition of a WSe2 layer in the trilayer leads to significantly higher photoluminescence quantum yields and tunable spectral resonance compared to its bilayer heterostructures at cryogenic temperatures. The observed enhancement in the photoluminescence quantum yield is due to significantly larger electron-hole overlap and higher light absorbance in the trilayer heterostructure, supported via first-principles pseudopotential calculations based on spin-polarized density functional theory. We further uncover the temperature-and power-dependence, as well as time-resolved photoluminescence of the trilayer heterostructure interlayer neutral excitons and trions. Our study elucidates the prospects of manipulating light emission from interlayer excitons and designing atomic heterostructures from first-principles for optoelectronics.