Exciton Dephasing in Tungsten Diselenide Atomic Layer

Abstract

An intrinsic exciton dephasing is the coherence loss of exciton dipole oscillation, while the total exciton dephasing originates from coherence loss due to exciton–exciton interaction and excitonphonon coupling. In this article, the total exciton dephasing time of tungsten diselenide (WSe2) atomic layers was analyzed as functions of excitation intensity with exciton–exciton coupling strength and temperature with exciton–phonon coupling strength. It was hypothesized that the total exciton dephasing time is shortened as the exciton–exciton interaction and the exciton–phonon coupling are increased. The coherence loss analysis revealed that the exciton dephasing time of WSe2 atomic layers is due to mainly the temperature rather than the excitation intensity.