title: Plasmon-enhanced light harvesting of chlorophylls on near-percolating silver films via one-photon anti-Stokes upconversion.
abstract: There exists a wealth of means of efficient utilization of solar energy in nature, with photosynthesis of chlorophylls as a prime example. Separately, artificially structured plasmonic materials are versatile in light harvesting and energy conversion. Using a simple and scalable design of near-percolating silver nanostructures, we demonstrate that the light-harvesting efficiency of chlorophylls can be drastically enhanced by tuning the plasmon frequency of the constituent silver nanoparticles to coincide with the maximal photon flux of sunlight. In particular, we show that the photon upconversion efficiency can be readily enhanced by over 20 folds, with the room-temperature fluorescence quantum yield increased by a factor of 2.63. The underlying mechanism for the upconversion enhancement is attributed to a one-electron-per-photon anti-Stokes process, involving absorption of a characteristic phonon mode of the chlorophylls. These findings suggest that chlorophylls can serve as molecular building blocks for high-efficiency light harvesting and solar energy conversion.
authors.affiliation: Department of Physics, Wuhan University, Wuhan 430072, PR China.
authors.forename: Ya-Lan
authors.initials: YL
authors.lastname: Wang
authors.forename: Fan
authors.initials: F
authors.lastname: Nan
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Zhou
authors.forename: Xiao-Niu
authors.initials: XN
authors.lastname: Peng
authors.forename: Zhang-Kai
authors.initials: ZK
authors.lastname: Zhou
authors.forename: Ying
authors.initials: Y
authors.lastname: Yu
authors.forename: Zhong-Hua
authors.initials: ZH
authors.lastname: Hao
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Qu-Quan
authors.initials: QQ
authors.lastname: Wang
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D002734:Chlorophyll / Q000737:chemistry*; D005453:Fluorescence; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D017785:Photons; D010788:Photosynthesis; D012834:Silver / Q000737:chemistry*; D012993:Solar Energy; D020349:Surface Plasmon Resonance
chemical_list: D002734:Chlorophyll; D012834:Silver