Efficient ZnO Nanowire Solid-State Dye-Sensitized Solar Cells Using Organic Dyes and Core−shell Nanostructures

We have applied a MgO and a ZrO 2 shell deposition method to control the interface between two indolene-based organic dyes in solid-state dye-sensitized solar cells. The shell deposition was carried out at less than 100 °C, and shell thickness was shown to be 2 nm for the ZrO 2 and 6−10 nm for the MgO by transmission electron microscopy. X-ray photoelectron spectroscopy has shown the initial ZnO NWs and core−shell structures have little surface water contamination. The use of suitable dyes, D102 and D149, has led to power conversion efficiency for ZnO NW based hybrid solar cells of 0.71%. Transient absorption measurements indicate that enhancements in photoinduced charge generation with core−shell formation are the main factor leading to the improved device efficiency.