Light Intensity Independent Electron Transport and Slow Charge Recombination in Dye-Sensitized In2O3 Solar Cells: In Contrast to the Case of TiO2

摘要

Dye-sensitized solar cells (DSCs) were fabricated from In2O3 nanoparticles with an electrolyte containing the I~-/I_3~- redox couple. Current transients were measured by a pulsed laser and a diode laser, showing light intensity independent current transients, which have not been seen from dye-sensitized TiO2, ZnO, and SnO2 solar cells. The response of the current transients was altered when bias potential was applied, suggesting that the electron transport is not due to diffusion. On the other hand, the lifetime, of injected electrons in the In2O3, while showing longer values than electrons in TiO2, displayed similar light intensity dependence to that observed in TiO2 DSCs, suggesting the interfacial electron transfer occurs in the Marcus normal region.