Charge recombination reduction in dye-sensitized solar cells by depositing ultrapure TiO2 nanoparticles on 'inert' BaTiO3 films

摘要

Ultrapure TiO2 nanoparticles (～5 nm in size) were supported on "inert" BaTiO3 films by TiCl4 treatment,which was used to fabricate dye-sensitized solar cells (DSSCs).The optimized electrode,designated as BaTiO3/TiO2(4),was obtained upon four cycles of TiCl4 treatment.DSSC with BaTiO3/TiO2(4) electrode exhibits superior power conversion efficiency (PCE) compared to that with conventional anatase TiO2 (～25nm in size) electrode.The interfacial charge recombination kinetics was investigated by electrochemical impedance spectroscopy (E1S) and intensity-modulated photocurrent/photovoltage spectroscopy (1MPS/IMVS).In contrast to DSSC with anatase TiO2 electrode,the dramatically enhanced electron lifetime for DSSC with BaTiO3/TiO2(4) electrode could be attributed to the decrease of recombination reaction at the TiO2 photoelectrode/electrolyte interface.It is proposed that the lower interfacial charge recombination can be related to the relatively shallower trap distributions in DSSC with BaTiO3/TiO2(4) electrode.