Photo & Electrochemical Energy Material Laboratory

Dye-sensitized solar cell

 

One of the biggest challenges ahead of human kind is to replace the fossil fuel with renewable energy sources while keeping pace with the worldwide increasing thirst for energy because of increasing population and rising demand from developing countries. This challenge has to be answered with a low-cost solution using abundantly available raw materials. As a representative device, dye-sensitized solar cell have been widely attracted since 1991 when the Michael Gratzel’s group reported the 7 % efficient dye-sensitized solar cells employing nanoporous TiO2 film. Dye-sensitized solar cell (DSSC) is consisted of mesoporous TiO2 working electrode, Pt counter electrode and electrolyte. In addition, dye molecules are absorbed on the TiO2 surface. The dye molecules absorb sunlight and generate photocurrent. Large surface area of mesorporous TiO2 enables to adsorb large amount of dye molecules. Therefore, high photocurrent can be generated.

 

Our research is focused on the development of efficient materials for DSSCs. Cell efficiency of about 15 % should be attained to compete against previous Si thin film solar cells. As a result, the research on the excellent nanomaterials such as one-dimensional TiO2 nanomaterials (i.e., TiO2 nanorod, nanotube, nanowire etc.), electrode design, and the relationship between their properties and side reactions will be performed. We have a technology to make one-dimensional TiO2 nanotube on Ti substrate and its application to DSSCs. Furthermore, the synthesis of 1-D structured metal oxides (TiO2, ZnO, SnO2, Nb2O5) based on various synthesis tool such as hydrothermal, sol-gel, anodization etc. can provide extensive range for the application to DSSCs.