Effects of a surfactant-templated nanoporous TiO2 interlayer on dye-sensitized solar cells

A 320 nm thick surfactant-templated nanoporous (STN) TiO(2) layer prepared from block copolymer P123 [poly(ethylene oxide)(20)-poly(propylene oxide)(70)-poly(ethylene oxide)(20)] was used as an interlayer between a 21 mu m thick mesoporous TiO(2) layer and a transparent conducting oxide. The thin STN TiO(2) interlayer had well-dispersed nanoporous features, which made it possible to adsorb dye molecules in the interlayer. In addition, it provided an enhanced electron lifetime, resulting in a reduced recombination rate and an increased diffusion length. The dye-sensitized solar cell with the thin STN interlayer resulted in a significantly increased overall energy conversion efficiency from 7.11% to 9.22% with an improvement of all parameters (short-circuit current, open circuit voltage, and fill factor).