title: Light trapping for solar fuel generation with Mie resonances.
abstract: The implementation of solar fuel generation as a clean, terawatt-scale energy source is critically dependent on the development of high-performance, inexpensive photocatalysts. Many candidate materials, including for example α-Fe2O3 (hematite), suffer from very poor charge transport with minority carrier diffusion lengths that are significantly shorter (nanometer scale) than the absorption depth of light (micrometer scale near the band edge). As a result, most of the photoexcited carriers recombine rather than participate in water-splitting reactions. For this reason, there is a tremendous opportunity for photon management. Plasmon-resonant nanostructures have been employed to effectively enhance light absorption in the near-surface region of photocatalysts, but this approach suffers from intrinsic optical losses in the metal. Here, we circumvent this issue by driving optical resonances in the active photocatalyst material itself. We illustrate that judiciously nanopatterned photocatalysts support optical Mie and guided resonances capable of substantially enhancing the photocarrier generation rate within 10-20 nm from the water/photocatalyst interface.
authors: Geballe Laboratory for Advanced Materials , 476 Lomita Mall, Stanford, California 94305-4045, United States.
authors: Soo Jin
authors: SJ
authors: Kim
authors: Isabell
authors: I
authors: Thomann
authors: Junghyun
authors: J
authors: Park
authors: Ju-Hyung
authors: JH
authors: Kang
authors: Alok P
authors: AP
authors: Vasudev
authors: Mark L
authors: ML
authors: Brongersma
mesh_terms: D002384:Catalysis; D005290:Ferric Compounds / Q000737:chemistry*; D008027:Light; D049329:Nanostructures / Q000737:chemistry*; D055668:Photochemical Processes; D012993:Solar Energy; D014867:Water / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D014867:Water; C000499:ferric oxide