Achieving localized light emission from monolayer two-dimensional (2D) transition metal dichalcogenides (TMDs) embedded in the matrix of another TMD has been theoretically proposed but not experimentally proven. In this study, we used cathodoluminescence performed in a scanning transmission electron microscope to unambiguously resolve localized light emission from 2D monolayer MoSe2 nanodots of varying sizes embedded in monolayer WSe2 matrix. We observed that the light emission strongly depends on the nanodot size wherein the emission is dominated by MoSe2 excitons in dots larger than 85 nm, and by MoSe2/WSe2 interface excitons below 50 nm. Interestingly, at extremely small dot sizes (< 10 nm), the electron energy levels in the nanodot become quantized, as demonstrated by a striking blue-shift in interface exciton emission, thus inducing quantum confined luminescence. These results establish controllable light emission from spatially confined 2D nanodots, which holds potential to be generalized to other 2D systems towards future nanophotonic applications.
@article{arxiv.2406.10315,
title = {Quantum Confined Luminescence in Two dimensions},
author = {Saiphaneendra Bachu and Fatimah Habis and Benjamin Huet and Steffi Y. Woo and Leixin Miao and Danielle Reifsnyder Hickey and Gwangwoo Kim and Nicholas Trainor and Kenji Watanabe and Takashi Taniguchi and Deep Jariwala and Joan M. Redwing and Yuanxi Wang and Mathieu Kociak and Luiz H. G. Tizei and Nasim Alem},
journal= {arXiv preprint arXiv:2406.10315},
year = {2025}
}
Comments
40 pages total, 5 figures in main text and 12 figures in Supporting Information, submitted to Nature Materials as of 06/14/2024