Bandgap recovery of monolayer MoS2 using defect engineering and chemical doping

• Published in: RSC advances Vol. 11; no. 34; pp. 20893 - 20898
• Main Authors: Aryeetey, Frederick, Pourianejad, Sajedeh, Ayanbajo, Olubukola, Nowlin, Kyle, Ignatova, Tetyana, Aravamudhan, Shyam
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 11.06.2021; The Royal Society of Chemistry
• Subjects: Carrier density; Chemistry; Energy gap; Helium ions; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Light emission; Molybdenum disulfide; Monolayers; Optical properties; Photoluminescence; Tetracyanoquinodimethane; Transition metal compounds
• DOI: 10.1039/d1ra02888j
• ISSN: 2046-2069

Two-dimensional transition metal dichalcogenide materials have created avenues for exciting physics with unique electronic and photonic applications. Among these materials, molybdenum disulfide is the most known due to extensive research in understanding its electronic and optical properties. In this paper, we report on the successful growth and modification of monolayer MoS2 (1L MoS2) by controlling carrier concentration and manipulating bandgap in order to improve the efficiency of light emission. Atomic size MoS2 vacancies were created using a Helium Ion Microscope, then the defect sites were doped with 2,3,5,6-tetrafluro7,7,8,8-tetracyanoquinodimethane (F4TCNQ). The carrier concentration in intrinsic (as-grown) and engineered 1L MoS2 was calculated using Mass Action model. The results are in a good agreement with Raman and photoluminescence spectroscopy as well as Kelvin probe force microscopy characterizations.