Hybrid solar cells based on poly(3-hexylthiophene) and electrospun TiO2 nanofibers with effective interface modification

Abstract

Electrospinning, a low cost production method for large area nanofibrous films, is employed to fabricate organic-inorganic hybrid solar cells based on poly(3-hexylthiophene) and TiO₂ nanofibers. The performance of the hybrid solar cells is optimized by modifying the surface of TiO₂ nanofibers with ruthenium dye (N719) and 3-phenylpropionic acid, which results in the average power conversion efficiency of about 1.1% under AM 1.5G simulated illumination (100 mW cm⁻²). It is found that the co-modification of N719 and 3-phenylpropionic acid on TiO₂ can induce more ordered backbone packing of poly(3-hexylthiophene) layer, lower density of trap states on the surface of TiO₂ and longer lifetime of carriers in the active layer due to retarded recombination process by the modifier. Therefore the interface modification can dramatically enhance the photovoltaic performance.