Binding energy and decaytime of exciton in dielectric medium


Güvendi A. , Şahin R., Sucu Y.

European Physical Journal B, cilt.94, sa.1, ss.1-7, 2021 (SCI İndekslerine Giren Dergi)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 94 Konu: 1
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1140/epjb/s10051-020-00030-6
  • Dergi Adı: European Physical Journal B
  • Sayfa Sayıları: ss.1-7

Özet

We developed a unique model for exciton in monolayer medium with an effective dielectric constant ϵeff (in which the monolayer material is placed on a substrate such as fused silica glass or SiO2 in experiments). Our model was based on an exact solution of the corresponding fully-covariant two-body Dirac-Coulomb type equation. For singlet quantum state of a static electron-hole pair in such a medium, we obtained a non-perturbative frequency spectrum composed of real and imaginary parts. We obtained explicit expressions for practical calculations of binding energy and decaytime of such a system. The results show that one can actively tune both binding energy and decaytime of an exciton during photo-excitation experiments by adjusting the value of ϵeff. We think that our calculations and approaches eliminate cross-talk in the literature and explain the discrepancy between experimental results of binding energy of an exciton for different substrates.