title: Reduced dielectric screening and enhanced energy transfer in single- and few-layer MoS2.
abstract: We report highly efficient nonradiative energy transfer from cadmium selenide (CdSe) quantum dots to monolayer and few-layer molybdenum disulfide (MoS2). The quenching of the donor quantum dot photoluminescence increases as the MoS2 flake thickness decreases with the highest efficiency (>95%) observed for monolayer MoS2. This counterintuitive result arises from reduced dielectric screening in thin layer semiconductors having unusually large permittivity and a strong in-plane transition dipole moment, as found in MoS2. Excitonic energy transfer between a zero-dimensional emitter and a two-dimensional absorber is fundamentally interesting and enables a wide range of applications including broadband optical down-conversion, optical detection, photovoltaic sensitization, and color shifting in light-emitting devices.
authors.affiliation: Department of Chemical Engineering and ‡Department of Chemistry, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Ferry
authors.initials: F
authors.lastname: Prins
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Goodman
authors.forename: William A
authors.initials: WA
authors.lastname: Tisdale
keywords: MoS2; Transition metal dichalcogenides; energy transfer; quantum dot