Trion induced photoluminescence and brightening of intervalley excitons in a doped MoS₂ monolayer

Transition metal dichalcogenide monolayers are direct bandgap semiconductors with the rich interplay of the valley and spin degrees of freedom. Strong Coulomb interaction leads to tightly bound excitons and trions, a quasiparticle composed of two electrons and a hole. We report Bethe-Salpeter equation solution for the three-particle wavefunction in the basis set of model Hamiltonian for single particles. The calculated absorption [1] and photoluminescence [2] spectra as a function of doping and temperature reproduce existing experimental data in MoS₂ monolayer and predict novel spectroscopic features due to the brightening of the intervalley excitons at finite doping.

[1] Y. V. Zhumagulov, A. Vagov, P. E. Faria Junior, D. R. Gulevich, V. Perebeinos,
“Trion induced photoluminescence of a doped MoS₂ monolayer”, J. Chem. Phys. 153, 044132 (2020)
[2] Y. V. Zhumagulov, A. Vagov, N. Y. Senkevich, D. R., Gulevich, and V. Perebeinos,
“Three-particle states and brightening of intervalley excitons in a doped MoS₂ monolayer”
Phys. Rev. B 101, 245433 (2020)