Programme

P.104 -- Posters, VCTP-50

Date: Thursday, 7 August 2025

Time: 08:30 - 10:00

An analytical approach to retrieving fundamental structural parameters of monolayer transition metal dichalcogenides from exciton spectra

Duy-Nhat Ly1 and Van-Hoang Le1

1Ho Chi Minh City University of Education, Ho Chi Minh City Vietnam;

The bandgap, dielectric constant, and screening length are key parameters defining monolayer transition metal dichalcogenides' electronic and optical properties (TMDCs). Determining these parameters accurately is challenging, as it often requires complex and consuming computational methods or complicated experiments. This report presents an efficient analytical framework for retrieving these fundamental structural parameters from exciton energy spectra in a magnetic field. Based on recent work [1], where exact analytical expressions for exciton spectra were obtained, we derive analytical formulas for the bandgap, dielectric constant, and screening length from experimental exciton energies. The idea originates from solving the inverse problem (exciton energy spectra $\to$ fundamental structural parameters) —as proposed in our earlier work [2]. The analytical formulas presented here are validated against experimental data and show excellent agreement across various TMDC materials. Moreover, the method significantly reduces computational complexity by avoiding the simultaneous fitting of multiple parameters. A comparison with results based on the Rytova–Keldysh potential shows deviations within 1.0 meV, even in strong magnetic fields.

Presenter: Lý Duy Nhất