Photoelectrochemical properties of ruthenium dye-sensitized nanocrystalline SnO2:TiO2 solar cells

The photoelectrochemical properties of RuL2(NCS)2 dye-sensitized nanocrystalline SnO2:TiO2 coupled and composite solar cells are reported. The coupled (bilayer) system shows higher incident photon-to-current conversion efficiency (IPCE) value than the composite (mixture) system. A maximum IPCE value attained 82.4% at 530 nm wavelength in the coupled system with 3.5 μm-thick SnO2 and 7 μm-thick TiO2. The higher IPCE value in the coupled system is attributed to the promotion of the charge separation by fast electron transfer process in the SnO2/TiO2/RuL2(NCS)2 system with different energy levels, different conduction band edge energy positions.