Three-particle states and brightening of intervalley excitons in a doped MoS${}_2$ monolayer

Abstract

Optical spectra of two-dimensional transition-metal dichalcogenides (TMDC) are influenced by complex multi-particle excitonic states. Their theoretical analysis requires solving the many-body problem, which in most cases, is prohibitively complicated. In this work, we calculate the optical spectra by exact diagonalization of the three-particle Hamiltonian within the Tamm-Dancoff approximation where the doping effects are accounted for via the Pauli blocking mechanism, modelled by a discretized mesh in the momentum space. The single-particle basis is extracted from the {\it ab initio} calculations. Obtained three-particle eigenstates and the corresponding transition dipole matrix elements are used to calculate the linear absorption spectra as a function of the doping level. Results for negatively doped MoS${}_2$ monolayer (ML) are in an excellent quantitative agreement with the available experimental data, validating our approach. The results predict additional spectral features due to the intervalley exciton that is optically dark in an undoped ML but is brightened by the doping. Our approach can be applied to a plethora of other atomically thin semiconductors, where the doping induced brightening of the many-particle states is also anticipated.

References in corpus (10)

• Valley polarization in MoS2 monolayers by optical pumping
• Two-Dimensional Material Nanophotonics
• Integrated Circuits Based on Bilayer MoS2 Transistors
• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
• Robust optical emission polarization in MoS2 monolayers through selective valley excitation
• Light Generation and Harvesting in a Van der Waals Heterostructure
• Exciton band structure of monolayer MoS2
• Trion induced negative photoconductivity in monolayer MoS2
• Many-Body Theory of Trion Absorption Features in Two-Dimensional Semiconductors
• Trion and Biexciton in Monolayer Transition Metal Dichalcogenides

Cited by in corpus (10)

• Electron-exciton interactions in the exciton-polaron problem
• Trion induced photoluminescence of a doped MoS2 monolayer
• Charge transfer and asymmetric coupling of MoSe${}_2$ valleys to the magnetic order of CrSBr
• Microscopic theory of exciton and trion polaritons in doped monolayers of transition metal dichalcogenides
• Variationally optimized orbital approach to trions in two-dimensional materials
• Effect of fermion indistinguishability on optical absorption of doped two-dimensional semiconductors
• Nonlinear spectroscopy of excitonic states in transition metal dichalcogenides
• Component exchange theory of trions
• Electrostatic control of the trion fine structure in transition metal dichalcogenide monolayers
• Semiclassical approach for excitonic spectrum of Coulomb coupling between two Dirac particles