Influence of Stoichiometry on the Optical and Electrical Properties of Chemical Vapor Deposition Derived MoS2
Citations Over TimeTop 1% of 2014 papers
Abstract
Ultrathin transition metal dichalcogenides (TMDCs) of Mo and W show great potential for digital electronics and optoelectronic applications. Whereas early studies were limited to mechanically exfoliated flakes, the large-area synthesis of 2D TMDCs has now been realized by chemical vapor deposition (CVD) based on a sulfurization reaction. The optoelectronic properties of CVD grown monolayer MoS2 have been intensively investigated, but the influence of stoichiometry on the electrical and optical properties has been largely overlooked. Here we systematically vary the stoichiometry of monolayer MoS2 during CVD via controlled sulfurization and investigate the associated changes in photoluminescence and electrical properties. X-ray photoelectron spectroscopy is employed to measure relative variations in stoichiometry and the persistence of MoOx species. As MoS2-δ is reduced (increasing δ), the field-effect mobility of monolayer transistors increases while the photoluminescence yield becomes nonuniform. Devices fabricated from monolayers with the lowest sulfur content have negligible hysteresis and a threshold voltage of ∼ 0 V. We conclude that the electrical and optical properties of monolayer MoS2 crystals can be tuned via stoichiometry engineering to meet the requirements of various applications.
Related Papers
- → Study of the synthesis process of non-stoichiometric TiC in Cu-Ti melts(2018)8 cited
- → On the stoichiometry of HgI2(1981)40 cited
- → The non-stoichiometry of tetracyanocomplexes(1981)7 cited
- → Spectrophotometric determination of the reaction stoichiometry of the reduction of octacyanotungstate(V) by hydroxylamine in acidic and basic media(1989)
- Laser induced oxidation and optical properties of stoichiometric and non-stoichiometric Bi2Te3 nanoplates(2015)