title: Ultrafast Charge Transfer and Enhanced Absorption in MoS2-Organic van der Waals Heterojunctions Using Plasmonic Metasurfaces.
abstract: Hybrid organic-inorganic heterostructures are attracting tremendous attention for optoelectronic applications due to their low-cost processing and high performance in devices. In particular, van der Waals p-n heterojunctions formed between inorganic two-dimensional (2D) materials and organic semiconductors are of interest due to the quantum confinement effects of 2D materials and the synthetic control of the physical properties of organic semiconductors, enabling a high degree of tunable optoelectronic properties for the heterostructure. However, for photovoltaic applications, hybrid 2D-organic heterojunctions have demonstrated low power conversion efficiencies due to the limited absorption from constraints on the physical thickness of each layer. Here, we investigate the ultrafast charge transfer dynamics between an organic polymer:fullerene blend and 2D n-type MoS2using transient pump-probe reflectometry. We employ plasmonic metasurfaces to enhance the absorption and charge photogeneration within the physically thin hybrid MoS2-organic heterojunction. For the hybrid MoS2-organic heterojunction in the presence of the plasmonic metasurface, the charge generation within the polymer is enhanced 6-fold, and the total active layer absorption bandwidth is increased by 90 nm relative to the polymer:fullerene blend alone. We demonstrate that MoS2-organic heterojunctions can serve as hybrid solar cells, and their efficiencies can be improved using plasmonic metasurfaces.
authors.affiliation: Department of Materials Science and Engineering, Rutgers University , 607 Taylor Road, Piscataway, New Jersey 08854, United States.|Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University , 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Petoukhoff
authors.affiliation: Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University , 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan.
authors.forename: M Bala Murali
authors.initials: MB
authors.lastname: Krishna
authors.affiliation: Department of Materials Science and Engineering, Rutgers University , 607 Taylor Road, Piscataway, New Jersey 08854, United States.
authors.forename: Damien
authors.initials: D
authors.lastname: Voiry
authors.affiliation: Department of Materials Science and Engineering, Rutgers University , 607 Taylor Road, Piscataway, New Jersey 08854, United States.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Bozkurt
authors.affiliation: Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University , 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan.
authors.forename: Skylar
authors.initials: S
authors.lastname: Deckoff-Jones
authors.affiliation: Department of Materials Science and Engineering, Rutgers University , 607 Taylor Road, Piscataway, New Jersey 08854, United States.
authors.forename: Manish
authors.initials: M
authors.lastname: Chhowalla
authors.affiliation: Department of Materials Science and Engineering, Rutgers University , 607 Taylor Road, Piscataway, New Jersey 08854, United States.|Department of Chemistry and Chemical Biology, Rutgers University , 610 Taylor Road, Piscataway, New Jersey 08854, United States.
authors.forename: Deirdre M
authors.initials: DM
authors.lastname: O'Carroll
authors.affiliation: Femtosecond Spectroscopy Unit, Okinawa Institute of Science and Technology Graduate University , 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan.
authors.forename: Keshav M
authors.initials: KM
authors.lastname: Dani
keywords: charge transfer; hybrid organic−inorganic heterostructures; plasmonic metasurfaces; solar energy; two-dimensional materials; ultrafast pump−probe dynamics