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.

Ultrasmooth and Thermally Stable Silver-Based Thin Films with Subnanometer Roughness by Aluminum Doping

“…There is a broad dip for the pure Ag and AA-130 films when the thickness is less than the percolation threshold. This originates from the localized surface plasmon resonance (LSPR) of electrically discontinuous metal island films. , Once the thickness of the films reaches the percolation threshold and beyond, the reflection increases toward the infrared regime, as is the case of a typical continuous metal film, leading to a gradual decrease in the film transmittance. The 6 nm AA-130 film is highly transparent, with the transmission of over 65% in the whole visible range (400–800 nm).…”

Coherent perfect absorption in deeply subwavelength films in the single-photon regime

“…Recent studies provided unexpected but strong evidence that the quantum properties of light are conserved when photons are converted into surface plasmon polaritons, paving the way for active and ultrafast quantum plasmonic technologies 1 2 3 4 5 6 7 and stimulating a broad interest for the topic. At the same time, light interaction with nanostructured and nanotextured materials exploiting plasmonic resonances is a rapidly growing field of research with potential applications in photovoltaics 8 , water photocatalysis 9 10 , artificial photosynthesis 11 12 , light harvesting for heating and light sources with engineered emissivity 13 . Furthermore, plasmonics plays a crucial role in the electromagnetic coupling of molecules to quantum dots and metal nanoparticles or nanowires 4 14 .…”

Tailoring Plasmonic Enhanced Upconversion in Single NaYF4:Yb3+/Er3+ Nanocrystals

“…Manipulating light-matter interactions at the nanoscale using metallic nanostructure has been shown to be a very promising route for enhancing light emitters via plasmonic resonances 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 . Examples include plasmonic enhanced spontaneous emission 25 26 27 28 29 30 31 32 , Raman scattering 33 34 35 36 37 38 39 40 41 , and nonlinear optical processes 42 43 44 . This strategy has also been adopted to enhance the upconversion efficiency for rare-earth salts 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 .…”