Shape Dependence of SiO2 Nanomaterials in a Quasi-Solid Electrolyte for Application in Dye-Sensitized Solar Cells

Abstract

Dye-sensitized solar cells (DSSCs) with a quasi-solid electrolyte, which are based on nanocomposites of the poly(ethylene glycol) dimethyl ether (PEGDME) oligomer with nanometer-sized spherelike and rodlike SiO2 nanomaterials, exhibit a higher energy conversion efficiency than do those with a liquid electrolyte. SiO2 nanorods were prepared using an electrospinning technique, and the structural effect of the SiO2 nanomaterials in the electrolyte on the DSSC was studied. In the presence of the SiO2 nanomaterials, the diffusion of the redox couple was enhanced, resulting in a higher photovoltaic performance. By changing the shape from sphere to rod, the photocurrent of the DSSC increased up to 12.0 mA cm(-2), and a 38% increase in the cell efficiency under AM1 illumination at 100 mW cm(-2) with masking was observed. Since the recombination also increased with the addition of rodlike SiO2 nanomaterials, generation 5, polyester-32-hydroxyl-1-carboxyl 2,2-bis-(hydroxylmethyl)propionic acid dendrons terminated in carboxylic acid moieties were employed as coadsorbents to reduce the recombination; the photocurrent value for the DSSCs was determined to be 14.1 mA cm(-2), and the power conversion efficiency increased by as much as 47% in the quasi-solid electrolyte DSSCs containing rodlike silica nanomaterials.