Light-trapping photoanode using high refractive index rutile TiO2 microspheres as sandwiched layer

• Light-trapping photoelectrode is proposed and fabricated.
• The photoelectrode uses high-refractive-index rutile TiO2 as sandwiched layer.
• A cell-efficiency of 10.05% was achieved by using light-trapping electrode.
• Light-trapping electrode can increase cell-efficiency by 18% when compared with the traditional double layer electrode.

The light-trapping TiO2 electrode is proposed and prepared originally by employing the high-refractive-index rutile TiO2 microspheres sandwiched between two layers of the low-refractive-index anatase TiO2 nanoparticles. Owing to its excellent light-trapping property, the dye-sensitized solar cells based on this electrode exhibit a total efficiency of 10.05%, which is 18% higher than that of traditional dye-sensitized solar cells based on high-index rutile TiO2 as a top reflecting layer. This TiO2 electrode with symmetrical structure is a promising candidate for applications in the TiO2 based photoelectric device.