Novel ITO/arc-TiO2 antireflective conductive substrate for transmittance enhanced properties in dye-sensitized solar cells

Abstract

Graphical abstractDisplay Omitted HighlightsWe fabricated ITO/arc-TiO2 antireflective TCO with blocking layer capability for DSSCs.Two maximum transmittance peaks around 410nm and 750nm could be seen.We fabricated DSSC based on the novel substrate and the uncoated ITO.IPCE spectra show a quench mimics the transmittance spectra.Overall device performance up to 50% was achieved with the use of novel substrate. A novel antireflective TiO2 compact layer (arc-TiO2) that can improve transmittance is employed by radio frequency sputtering at the interface between ITO and porous-TiO2. Effects of the absence and presence of the TiO2 layer were mainly investigated by means of incident photon-to-current efficiency (IPCE), open-circuit voltage decay (OCVD) and electrochemical impedance spectroscopy (EIS). The sensitization effect of N719 dye has been improved due to the right-shifted transmittance spectra as shown by IPCE measurement. The slow decay behaviour of the photo-voltage attributed to the merits brought by the compact layer has been evidenced by the OCVD measurement. The improvement of adhesion between the arc-TiO2 film and porous-TiO2 has decreased the interfacial resistance R1 in the EIS measurement, and this facilitated the charge transfer process of the electron in the dye-sensitized solar cells (DSSC) later on. A remarkable improvement in the overall conversion efficiency of 3.444%, representing almost 50% increment compared to the cell without the compact layer, is mainly responsible for the higher transmittance and fewer recombination effects of the arc-TiO2 compact layer employed in the DSSC.