TY - JOUR
T1 - Characterization of Rotational Stacking Layers in Large-Area MoSe2 Film Grown by Molecular Beam Epitaxy and Interaction with Photon
AU - Choi, Yoon Ho
AU - Lim, Dong Hyeok
AU - Jeong, Jae Hun
AU - Park, Dambi
AU - Jeong, Kwang Sik
AU - Kim, Minju
AU - Song, Aeran
AU - Chung, Hee Suk
AU - Chung, Kwun Bum
AU - Yi, Yeonjin
AU - Cho, Mann Ho
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/9/13
Y1 - 2017/9/13
N2 - Transition metal dichalcogenides (TMDCs) are promising next-generation materials for optoelectronic devices because, at subnanometer thicknesses, they have a transparency, flexibility, and band gap in the near-infrared to visible light range. In this study, we examined continuous, large-area MoSe2 film, grown by molecular beam epitaxy on an amorphous SiO2/Si substrate, which facilitated direct device fabrication without exfoliation. Spectroscopic measurements were implemented to verify the formation of a homogeneous MoSe2 film by performing mapping on the micrometer scale and measurements at multiple positions. The crystalline structure of the film showed hexagonal (2H) rotationally stacked layers. The local strain at the grain boundaries was mapped using a geometric phase analysis, which showed a higher strain for a 30° twist angle compared to a 13° angle. Furthermore, the photon-matter interaction for the rotational stacking structures was investigated as a function of the number of layers using spectroscopic ellipsometry. The optical band gap for the grown MoSe2 was in the near-infrared range, 1.24-1.39 eV. As the film thickness increased, the band gap energy decreased. The atomically controlled thin MoSe2 showed promise for application to nanoelectronics, photodetectors, light emitting diodes, and valleytronics.
AB - Transition metal dichalcogenides (TMDCs) are promising next-generation materials for optoelectronic devices because, at subnanometer thicknesses, they have a transparency, flexibility, and band gap in the near-infrared to visible light range. In this study, we examined continuous, large-area MoSe2 film, grown by molecular beam epitaxy on an amorphous SiO2/Si substrate, which facilitated direct device fabrication without exfoliation. Spectroscopic measurements were implemented to verify the formation of a homogeneous MoSe2 film by performing mapping on the micrometer scale and measurements at multiple positions. The crystalline structure of the film showed hexagonal (2H) rotationally stacked layers. The local strain at the grain boundaries was mapped using a geometric phase analysis, which showed a higher strain for a 30° twist angle compared to a 13° angle. Furthermore, the photon-matter interaction for the rotational stacking structures was investigated as a function of the number of layers using spectroscopic ellipsometry. The optical band gap for the grown MoSe2 was in the near-infrared range, 1.24-1.39 eV. As the film thickness increased, the band gap energy decreased. The atomically controlled thin MoSe2 showed promise for application to nanoelectronics, photodetectors, light emitting diodes, and valleytronics.
KW - dielectric dispersion
KW - localized strain
KW - molecular beam epitaxy
KW - molybenum diselenides
KW - optical band gap
KW - rotational layer
KW - transition metal dichalcogenids
UR - http://www.scopus.com/inward/record.url?scp=85029492235&partnerID=8YFLogxK
U2 - 10.1021/acsami.7b05475
DO - 10.1021/acsami.7b05475
M3 - Article
C2 - 28809109
AN - SCOPUS:85029492235
SN - 1944-8244
VL - 9
SP - 30786
EP - 30796
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 36
ER -