Defect formation on MoS$_{\mathrm{2}}$ via methanol to methoxy conversion
ORAL
Abstract
Coverage dependent defect formation, via methanol adsorption on MoS$_{\mathrm{2\thinspace }}$and conversion into methoxy, was investigated utilizing scanning tunneling microscopy. Low Temperature adsorption of methanol on MoS$_{\mathrm{2}}$ at 110 K followed by annealing of the sample near 350 K conversion as well as adsorption of methanol on MoS$_{\mathrm{2}}$ at 350 K results in the formation of numerous point defects at the surface of the MoS$_{\mathrm{2}}$ substrate. Larger multi-point defects, nominally \textasciitilde 1 nm in size as well as line defects on the MoS$_{\mathrm{2}}$ sample surface become increasingly apparent with multiple cycles of methanol exposure and annealing. Preliminary luminescence studies of extensive methanol exposure to MoS$_{\mathrm{2}}$ supports defect formation in MoS$_{\mathrm{2\thinspace }}$monolayers, based on the significant quenching of luminescence. Temperature dependent luminescence of micro-particles of MoS$_{\mathrm{2}}$ with excess methanol again indicate compositional changes and defect formation of MoS$_{\mathrm{2}}$ via observed color change of material and sharp quenching of luminescence near the 350 K conversion temperature. The experimental results will be compared with density functional theory.
*Funded under U.S. Department of Energy grant DE-FG02-07ER15842
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