Improved spectral response of sensitized photoelectrodes with the optical modulation layer

We demonstrated that TiO2 compact layers (c-TiO2) can modulate optical transmittance of transparent conducting oxide (TCO) substrates and improve spectral response of a dye-sensitized solar cell (DSSC). The transmittance spectra of TCO substrates were controlled with the thickness of c-TiO2 layers, which in turn, influenced the incident photon-to-current conversion efficiency of DSSCs. The overall energy conversion efficiency of the DSSC with a 210 nm-thick c-TiO2 layer was increased by 16% compared to the DSSC with a 40 nm-thick c-TiO2 layer, due to the higher optical transmittance of the TCO substrate.

► The optical transmittance of TCO can be modulated by coating a compact TiO2 layer. ► The modulated optical transmittance directly influences spectral responses of DSSCs. ► The energy conversion efficiency was improved by 16% with the optical modulation. ► Proper optical modulation can lead to the fabrication of the sensitizer-specific TCO.