Postgrowth Tuning of the Bandgap of Single-Layer Molybdenum Disulfide Films by Sulfur/Selenium Exchange
Abbreviated Journal Title
molybdenum disulfide; molybdenum diselenide; transition metal; dichalcogenides; CVD; sputtering; bandgap engineering; atomically thin; films; METAL DICHALCOGENIDE ALLOYS; MONOLAYER MOS2; VALLEY POLARIZATION; ATOMIC; LAYERS; PHOTOLUMINESCENCE; GRAPHENE; ELECTRONICS; NANOSHEETS; GROWTH; PHASE; Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience &; Nanotechnology; Materials Science, Multidisciplinary
We demonstrate bandgap tuning of a single-layer MoS2 film on SiO2/Si via substitution of its sulfur atoms by selenium through a process of gentle sputtering, exposure to a selenium precursor, and annealing. We characterize the substitution process both for S/S and S/Se replacement Photoluminescence and, in the latter case, X-ray photoelectron spectroscopy provide direct evidence of optical band gap shift and selenium incorporation, respectively. We discuss our experimental observations, including the limit of the achievable bandgap shift, in terms of the role of stress in the film as elucidated by computational studies, based on density functional theory. The resultant films are stable in vacuum, but deteriorate under optical excitation In air.
"Postgrowth Tuning of the Bandgap of Single-Layer Molybdenum Disulfide Films by Sulfur/Selenium Exchange" (2014). Faculty Bibliography 2010s. 5755.