We theoretically investigate the energy of the ground state exciton confined to two-dimensional (2D) monolayers with circular shape. Within an effective mass approach employing a nonlocal screening effect on the Coulomb potential energy, we demonstrate how the exciton energy is correlated with the radius of the circle, electron-hole reduced mass, and 2D susceptibility. In addition, we show that a dead layer around the circle edge, into which the electron-hole pair cannot penetrate, is necessary for understanding the energy shift recently observed in monolayer WSe2 quantum dots.
@article{arxiv.1801.06923,
title = {Anomalous energy shift of laterally confined two-dimensional excitons},
author = {Shota Ono and Tomohiro Ogura},
journal= {arXiv preprint arXiv:1801.06923},
year = {2018}
}