Quasiparticle and Optical Properties of Carrier-Doped Monolayer MoTe₂ from First Principles
Abstract
The intrinsic weak and highly nonlocal dielectric screening of two-dimensional materials is well-known to lead to high sensitivity of their optoelectronic properties to environment. Less studied theoretically is the role of free carriers in those properties. Here, we use ab initio GW and Bethe-Salpeter equation calculations, with a rigorous treatment of dynamical screening and local-field effects, to study the doping dependence of the quasiparticle and optical properties of a monolayer transition-metal dichalcogenide, 2H MoTe₂. We predict a quasiparticle band gap renormalization of several hundreds of meV for experimentally attainable carrier densities and a similarly sizable decrease in the exciton binding energy. This results in an almost constant excitation energy for the lowest-energy exciton resonance with an increasing doping density. Using a newly developed and generally applicable plasmon-pole model and a self-consistent solution of the Bethe-Salpeter equation, we reveal the importance of accurately capturing both dynamical and local-field effects to understand detailed photoluminescence measurements.
Additional Information
© 2023 American Chemical Society. This work was primarily supported by the Center for Computational Study of Excited-state Phenomena in Energy Materials (C2SEPEM) at Lawrence Berkeley National Laboratory, funded by the US Department of Energy (DOE) under contract No. DE-AC02-05CH11231. The development of the plasmon-pole model was partially supported by the Theory of Materials FWP at Lawrence Berkeley National Laboratory under the same contract number. Computational resources were provided by the National Energy Research Scientific Computing Center (NERSC). A.C. acknowledges the support from Wallonie Bruxelles International under contract No. SUB/2021/512815. The authors declare no competing financial interest.Attached Files
Supplemental Material - nl3c00386_si_002.pdf
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Additional details
- Alternative title
- Quasiparticle and Optical Properties of Carrier-Doped Monolayer MoTe2 from First Principles
- Eprint ID
- 121441
- Resolver ID
- CaltechAUTHORS:20230519-895510000.3
- Department of Energy (DOE)
- DE-AC02-05CH11231
- Wallonie Bruxelles International
- SUB/2021/512815
- Created
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2023-06-28Created from EPrint's datestamp field
- Updated
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2023-06-28Created from EPrint's last_modified field