Rare Metals
Rapidly counting atomic planes of ultra-thin MoSe₂ nanosheets (1 ≤ n ≤ 4) on SiO₂/Si substrate
Rare Metals · 35, 632-636 (2016)
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Introduction
Optical contrast is used to identify one to four layers of MoSe₂ on SiO₂/Si substrates. Spectroscopic measurements are compared with a Fresnel model and checked against atomic-force microscopy.
A closer reading
Even a fixed monolayer changes apparent contrast with wavelength and oxide thickness. Calibrating the optics of the substrate makes the layer count more reliable than judging colour in an uncalibrated micrograph.