Dye-sensitized solar cells based on tin oxide nanowire network

Highly crystalline tin oxide nanowires grown through vapor-liquid-solid process were used in Dye- Sensitized Solar Cells (DSSCs). Back-illuminated structure was adopted due to the opaqueness of silicon substrate used to grow the nanowires. To provides a good understanding of using metal oxide nanowires in DSSC structure, the physical properties of nanowires such as length and diameter on the effect of solar cells performance were investigated through comparison and normalization. It was found that increase the nanowire length will enhance the cell performance first by providing large surface area for dye attachment while still maintains the direct path for charge transport. However, nanowire with a length that is too long would have an adverse effect on the electron collection efficiency. Nanowires with larger diameter showed a significant increase of current density hence the cell performance resulted from less scattering centers along the relatively larger charge transport channel. Through optimization, nanowires grown from 10 nm thick Au catalyst with the thickness around 40 μm exhibited the best cell performance of 0.18%.