Carbon doping of WS₂ monolayers: Bandgap reduction and p-type doping transport.

ABSTRACT: Chemical doping constitutes an effective route to alter the electronic, chemical, and optical properties of two-dimensional transition metal dichalcogenides (2D-TMDs). We used a plasma-assisted method to introduce carbon-hydrogen (CH) units into WS₂ monolayers. We found CH-groups to be the most stable dopant to introduce carbon into WS₂, which led to a reduction of the optical bandgap from 1.98 to 1.83 eV, as revealed by photoluminescence spectroscopy. Aberration corrected high-resolution scanning transmission electron microscopy (AC-HRSTEM) observations in conjunction with first-principle calculations confirm that CH-groups incorporate into S vacancies within WS₂. According to our electronic transport measurements, undoped WS₂ exhibits a unipola

SUBMITTER: Zhang F 

PROVIDER: S-EPMC6534391 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature