title: Energy Transfer from Quantum Dots to Graphene and MoS2: The Role of Absorption and Screening in Two-Dimensional Materials.
abstract: We report efficient nonradiative energy transfer (NRET) from core-shell, semiconducting quantum dots to adjacent two-dimensional sheets of graphene and MoS2 of single- and few-layer thickness. We observe quenching of the photoluminescence (PL) from individual quantum dots and enhanced PL decay rates in time-resolved PL, corresponding to energy transfer rates of 1-10 ns(-1). Our measurements reveal contrasting trends in the NRET rate from the quantum dot to the van der Waals material as a function of thickness. The rate increases significantly with increasing layer thickness of graphene, but decreases with increasing thickness of MoS2 layers. A classical electromagnetic theory accounts for both the trends and absolute rates observed for the NRET. The countervailing trends arise from the competition between screening and absorption of the electric field of the quantum dot dipole inside the acceptor layers. We extend our analysis to predict the type of NRET behavior for the near-field coupling of a chromophore to a range of semiconducting and metallic thin film materials.
authors.forename: Archana
authors.initials: A
authors.lastname: Raja
authors.forename: Andrés
authors.initials: A
authors.lastname: Montoya Castillo
authors.forename: Johanna
authors.initials: J
authors.lastname: Zultak
authors.forename: Xiao-Xiao
authors.initials: XX
authors.lastname: Zhang
authors.forename: Ziliang
authors.initials: Z
authors.lastname: Ye
authors.forename: Cyrielle
authors.initials: C
authors.lastname: Roquelet
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Chenet
authors.forename: Arend M
authors.initials: AM
authors.lastname: van der Zande
authors.forename: Pinshane
authors.initials: P
authors.lastname: Huang
authors.forename: Steffen
authors.initials: S
authors.lastname: Jockusch
authors.forename: James
authors.initials: J
authors.lastname: Hone
authors.forename: David R
authors.initials: DR
authors.lastname: Reichman
authors.forename: Louis E
authors.initials: LE
authors.lastname: Brus
authors.affiliation: Departments of Applied Physics and Photon Science, Stanford University , Stanford, California 94305, United States.|SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors.forename: Tony F
authors.initials: TF
authors.lastname: Heinz
keywords: Energy transfer; MoS2; dielectric screening; graphene; quantum dots; transition metal dichalcogenides