Mesoporous TiO? Bragg stack templated by graft copolymer for dye-sensitized solar cells.

ABSTRACT: Organized mesoporous TiO? Bragg stacks (om-TiO? BS) consisting of alternating high and low refractive index organized mesoporous TiO? (om-TiO?) films were prepared to enhance dye loading, light harvesting, electron transport, and electrolyte pore-infiltration in dye-sensitized solar cells (DSSCs). The om-TiO? films were synthesized via a sol-gel reaction using amphiphilic graft copolymers consisting of poly(vinyl chloride) backbones and poly(oxyethylene methacrylate) side chains, i.e., PVC-g-POEM as templates. To generate high and low index films, the refractive index of om-TiO? film was tuned by controlling the grafting ratio of PVC-g-POEM via atomic transfer radical polymerization (ATRP). A polymerized ionic liquid (PIL)-based DSSC fabricated with a 1.2-?m-thick om-TiO? BS-based photoanode exhibited an efficiency of 4.3%, which is much higher than that of conventional DSSCs with a nanocrystalline TiO? layer (nc-TiO? layer) (1.7%). A PIL-based DSSC with a heterostructured photoanode consisting of 400-nm-thick organized mesoporous TiO? interfacial (om-TiO? IF) layer, 7-?m-thick nc-TiO?, and 1.2-?m-thick om-TiO? BS as the bottom, middle and top layers, respectively, exhibited an excellent efficiency of 7.5%, which is much higher than that of nanocrystaline TiO? photoanode (3.5%).

SUBMITTER: Park JT 

PROVIDER: S-EPMC4076678 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature