title: Heterointerface Screening Effects between Organic Monolayers and Monolayer Transition Metal Dichalcogenides.
abstract: The nature and extent of electronic screening at heterointerfaces and their consequences on energy level alignment are of profound importance in numerous applications, such as solar cells, electronics etc. The increasing availability of two-dimensional (2D) transition metal dichalcogenides (TMDs) brings additional opportunities for them to be used as interlayers in "van der Waals (vdW) heterostructures" and organic/inorganic flexible devices. These innovations raise the question of the extent to which the 2D TMDs participate actively in dielectric screening at the interface. Here we study perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) monolayers adsorbed on single-layer tungsten diselenide (WSe2), bare graphite, and Au(111) surfaces, revealing a strong dependence of the PTCDA HOMO-LUMO gap on the electronic screening effects from the substrate. The monolayer WSe2 interlayer provides substantial, but not complete, screening at the organic/inorganic interface. Our results lay a foundation for the exploitation of the complex interfacial properties of hybrid systems based on TMD materials.
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore.
authors.forename: Yu Jie
authors.initials: YJ
authors.lastname: Zheng
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore.|Institute of Materials Research & Engineering (IMRE), A*STAR (Agency for Science, Technology and Research) , 2 Fusionopolis Way, Innovis, Singapore 138634, Singapore.
authors.forename: Yu Li
authors.initials: YL
authors.lastname: Huang
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore.|Centre for Advanced 2D Materials, National University of Singapore , Block S14, Level 6, 6 Science Drive 2, Singapore 117546, Singapore.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore.
authors.forename: Weijie
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore.|Centre for Advanced 2D Materials, National University of Singapore , Block S14, Level 6, 6 Science Drive 2, Singapore 117546, Singapore.|Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.
authors.forename: Goki
authors.initials: G
authors.lastname: Eda
authors.affiliation: Sandia National Laboratories , Livermore, California 94551, United States.
authors.forename: Catalin D
authors.initials: CD
authors.lastname: Spataru
authors.affiliation: SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University , Shenzhen 518060, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Electrophysics, National Chiao Tung University , Hsinchu 300, Taiwan.
authors.forename: Yung-Huang
authors.initials: YH
authors.lastname: Chang
authors.affiliation: Physical Sciences and Engineering, King Abdullah University of Science and Technology , Thuwal 23955-6900, Saudi Arabia.
authors.forename: Lain-Jong
authors.initials: LJ
authors.lastname: Li
authors.affiliation: Institute of Materials Research & Engineering (IMRE), A*STAR (Agency for Science, Technology and Research) , 2 Fusionopolis Way, Innovis, Singapore 138634, Singapore.
authors.forename: Dongzhi
authors.initials: D
authors.lastname: Chi
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore.|Centre for Advanced 2D Materials, National University of Singapore , Block S14, Level 6, 6 Science Drive 2, Singapore 117546, Singapore.|Institute of High Performance Computing, Agency for Science Technology and Research , 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore.
authors.forename: Su Ying
authors.initials: SY
authors.lastname: Quek
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore.|Centre for Advanced 2D Materials, National University of Singapore , Block S14, Level 6, 6 Science Drive 2, Singapore 117546, Singapore.
authors.forename: Andrew Thye Shen
authors.initials: AT
authors.lastname: Wee
keywords: energy level alignment; first principle calculations; organic−inorganic interface; scanning tunneling microscopy/spectroscopy; screening effects; two-dimensional transition metal dichalcogenides