Rapid, non-destructive evaluation of ultrathin WSe2 using spectroscopic ellipsometry

The utilization of tungsten diselenide (WSe2) in electronic and optoelectronic devices depends on the ability to understand and control the process-property relationship during synthesis. We demonstrate that spectroscopic ellipsometry is an excellent technique for accurate, non-destructive determina...

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Bibliographic Details
Published inAPL materials Vol. 2; no. 9; pp. 092508 - 092508-6
Main Authors Eichfeld, Sarah M., Eichfeld, Chad M., Lin, Yu-Chuan, Hossain, Lorraine, Robinson, Joshua A.
Format Journal Article
LanguageEnglish
Published AIP Publishing LLC 01.09.2014
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Summary:The utilization of tungsten diselenide (WSe2) in electronic and optoelectronic devices depends on the ability to understand and control the process-property relationship during synthesis. We demonstrate that spectroscopic ellipsometry is an excellent technique for accurate, non-destructive determination of ultra-thin (<30 nm) WSe2 properties. The refractive index (n) and extinction coefficient (k) were found to be independent of thickness down to 1.3 nm, and were used to determine film thickness, which was confirmed to be within 9% of values found via atomic force microscopy. Finally, the optical bandgap was found to closely correlate with thickness, ranging from 1.2 to 1.55 eV as the WSe2 is thinned to the equivalent of 2 atomic layers.
ISSN:2166-532X
2166-532X
DOI:10.1063/1.4893961