Novel tandem cell structure of dye-sensitized solar cell for improvement in photocurrent

A novel tandem cell structure is proposed to improve photocurrent of dye-sensitized solar cells (DSCs). Front and back parallel photoelectrodes are placed face-to-face; a common Pt-mesh counter electrode with transmittance is inserted between the electrodes. The short-circuit current density (Jsc) for the tandem cell is equivalent to the sum of the Jsc for the front and back photoelectrodes. A model using light energy absorbed by the photoelectrode is used to evaluate appropriate TiO2 film thickness of the front photoelectrode. The Jsc for the tandem cell was improved to 13.3 mA/cm2 for a cell with a 7.8-μm-thick front photoelectrode. The novel tandem cell has a great potential to improve DSC photocurrent and performance.