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-principle 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.
@article{arxiv.1706.05857,
title = {Enhanced interlayer neutral excitons and trions in trilayer van der Waals heterostructures},
author = {Chanyeol Choi and Jiahui Huang and Hung-Chieh Cheng and Hyunseok Kim and Abhinav Kumar Vinod and Sang-Hoon Bae and V. Ongun Ozcelik and Roberto Grassi and Jongjae Chae and Shu-Wei Huang and Xiangfeng Duan and Kristen Kaasbjerg and Tony Low and Chee Wei Wong},
journal= {arXiv preprint arXiv:1706.05857},
year = {2018}
}
Comments
25 pages, 5 figures(Maintext). 9 pages, 7 figures(Supplementary Information). - Accepted for publication in npg: 2D materials and applications and reformatted to its standard. - Updated co-authors and references. - Title and abstract are modified for clarity. - Errors have been corrected, npg: 2D materials and applications (2018)