TY - JOUR
T1 - Optical microscopy–based thickness estimation in thin GaSe flakes
AU - Zhang, Wenliang
AU - Zhao, Qinghua
AU - Puebla, Sergio
AU - Wang, Tao
AU - Frisenda, Riccardo
AU - Castellanos-Gomez, Andres
N1 - Publisher Copyright:
© 2021 The Authors
PY - 2021/6
Y1 - 2021/6
N2 - We have implemented three different optical methods to quantitatively assess the thickness of thin GaSe flakes transferred on both transparent substrates, like Gel-Film, and SiO2/Si substrates. We show how their apparent color can be an efficient way to make a quick, rough estimation of the thickness of the flakes. This method is more effective for SiO2/Si substrates as the thickness-dependent color change is more pronounced on these substrates than on transparent substrates. On the other hand, for transparent substrates, the transmittance of the flakes in the blue region of the visible spectrum can be used to estimate the thickness. We find that the transmittance of flakes in the blue part of the spectrum decreases at a rate of 1.2%/nm. On SiO2/Si, the thickness of the flakes can be accurately determined by fitting optical contrast spectra to a Fresnel law-based model. Finally, we also show how the quantitative analysis of transmission mode optical microscopy images can be a powerful method to quickly probe the environmental degradation of GaSe flakes exposed to aging conditions.
AB - We have implemented three different optical methods to quantitatively assess the thickness of thin GaSe flakes transferred on both transparent substrates, like Gel-Film, and SiO2/Si substrates. We show how their apparent color can be an efficient way to make a quick, rough estimation of the thickness of the flakes. This method is more effective for SiO2/Si substrates as the thickness-dependent color change is more pronounced on these substrates than on transparent substrates. On the other hand, for transparent substrates, the transmittance of the flakes in the blue region of the visible spectrum can be used to estimate the thickness. We find that the transmittance of flakes in the blue part of the spectrum decreases at a rate of 1.2%/nm. On SiO2/Si, the thickness of the flakes can be accurately determined by fitting optical contrast spectra to a Fresnel law-based model. Finally, we also show how the quantitative analysis of transmission mode optical microscopy images can be a powerful method to quickly probe the environmental degradation of GaSe flakes exposed to aging conditions.
KW - Fresnel
KW - Gallium selenide
KW - Optical identification
KW - Refractive index
UR - http://www.scopus.com/inward/record.url?scp=85104289307&partnerID=8YFLogxK
U2 - 10.1016/j.mtadv.2021.100143
DO - 10.1016/j.mtadv.2021.100143
M3 - 文章
AN - SCOPUS:85104289307
SN - 2590-0498
VL - 10
JO - Materials Today Advances
JF - Materials Today Advances
M1 - 100143
ER -