Molecular Alignment and Electronic Structure of N,N'-Dibutyl-3,4,9,10-perylene-tetracarboxylic-diimide Molecules on MoS2Surfaces.
The molecular orientation of organic semiconductors on a solid surface could be an indispensable factor to determine the electrical performance of organic-based devices. Despite its fundamental prominence, a clear description of the emergent two-dimensional layered material-organic interface is not fully understood yet. In this study, we reveal the molecular alignment and electronic structure of thermally deposited N,N'-dibutyl-3,4,9,10-perylene-dicarboximide (PTCDI-C4) molecules on natural molybdenum disulfide (MoS2) using near-edge X-ray absorption fine structure spectroscopy (NEXAFS). The average tilt angle determination reveals that the anisotropy in the π* symmetry transition of the carbon K-edge (284-288 eV range) is present at the sub-monolayer regime. Supported by ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), and resonant photoemission spectroscopy (RPES) measurements, we find that our spectroscopic measurements indicate a weak charge transfer established at the PTCDI-C4/MoS2interface. Sterical hindrance due to the C4 alkyl chain caused tilting of the molecular plane at the initial thin film deposition. Our result shows a tunable interfacial alignment of organic molecules on transition metal dichalcogenide surfaces effectively enhancing the electronic properties of hybrid organic-inorganic heterostructure devices.
Department of Physics, National University of Singapore , 2 Science Drive 3, 117542 Singapore.
http://orcid.org/0000-0003-4125-6099
Arramel
Department of Physics, National University of Singapore , 2 Science Drive 3, 117542 Singapore.|Singapore Synchrotron Light Source, National University of Singapore , 5 Research Link, Singapore 1176033.|SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University , Shenzhen 518060, China.
Xinmao
X
Yin
Department of Physics, National University of Singapore , 2 Science Drive 3, 117542 Singapore.
Qixing
Q
Wang
Department of Physics, National University of Singapore , 2 Science Drive 3, 117542 Singapore.
Yu J
YJ
Zheng
Department of Physics, National University of Singapore , 2 Science Drive 3, 117542 Singapore.
Zhibo
Z
Song
Department of Physics, National University of Singapore , 2 Science Drive 3, 117542 Singapore.
Mohammad H
MH
Bin Hassan
Department of Physics, National University of Singapore , 2 Science Drive 3, 117542 Singapore.
Dianyu
D
Qi
Department of Chemistry, National University of Singapore , 3 Science Drive 3, 117543 Singapore.
Jishan
J
Wu
Department of Physics, National University of Singapore , 2 Science Drive 3, 117542 Singapore.|Singapore Synchrotron Light Source, National University of Singapore , 5 Research Link, Singapore 1176033.|NUSNNI-NanoCore, National University of Singapore , Singapore 117411.
Andrivo
A
Rusydi
Department of Physics, National University of Singapore , 2 Science Drive 3, 117542 Singapore.
Andrew T S
AT
Wee
RPES; UPS; XPS; interface; near-edge X-ray absorption spectroscopy; perylene