Comparison of Different TiO2 Phase Structures and Morphologies on Dye-Sensitized Solar Cells

Dye-sensitized solar cells have been intensively studied as possible alternative to silicon solar cells. TiO₂ is the most common photoanode material used in high performance DSSCs and can exist in different forms and polymorphs that can affect their performance. The most common forms of TiO₂ are anatase and rutile. Generally, pure anatase exhibits higher photovoltaic activity compared to rutile TiO₂ and is widely accepted that the observed incident photocurrent conversion efficiency is mainly due to a higher dye loading in anatase TiO₂. Here, we demonstrate that anatase nanoparticles based DSSCs can have lower dye adsorption amount than rutile TiO₂ but exhibit better photovoltaic performance. It is revealed that the ability which rutile and anatase TiO₂ scatter incident light can be an important contributing factor to their performance difference. In this study, hydrothermal synthesis is the major method to fabricate anatase and rutile nanoparticles of different size and form.