Conductive nanorod arrays for solar cells

Abstract

Recently, with high fuel prices and growing concerns about the environmental pollution,

research and developments of alternatives in the field of clean energy have increased

tremendously. Photovoltaic devices would be an attractive alternative for the generation

of energy as electricity is generated directly from the abundances of sun light. Currently,

dye sensitized solar cells (DSSCs) are the subject of intense research in the framework

of renewable energies as a low-cost photovoltaic device. The main objective of the present work in this project is to study the incorporation of conductive SnO2 nanorod

arrays in DSSCs.

Overall, based on results obtained, DSSCs based on SnO2 nanorod arrays on both ITO

and FTO substrates have shown good improvement over the standard DSSCs by

allowing direct connection between the charge-generation sites and electrode. A variety of methods were employed to increase the efficiency of SnO2 nanorod DSSCs by filling

the gap in between the nanorods with TiO2 nanoparticles. The most promising approach

was growing nanorods using different deposition time, reported with less dense nanorod arrays attaining higher conversion efficiency.

The morphological properties of TiO2, especially layer thickness and particle size, play an important role in achieving respectable conversion efficiency. 3 different types of

TiO2 paste were synthesized in the study. The most promising result was shown by TiO2

paste synthesized from colloids using hydrothermal method, with a smaller TiO2 particle size (~15–20 nm) achievable, thus offers a larger surface area and allows the filling of

the gaps between the nanorod arrays more effectively. In addition, thicker TiO2 film (~7 μm) has shown a better performance attributed to greater adsorption of the dye

molecules on the film.