In this paper we focus on the effect of carboxylated thiophene small molecules as interface modifiers in TiO2/P3HT hybrid solar cells. Our results show that small differences in the chemical structure of these molecules, for example, the presence of the -CH2– group in the 2-thiopheneacetic acid (TAA), can greatly increase the TiO2 surface wettability, improving the TiO2/polymer contact. This effect is important to enhance exciton splitting and charge separation.
![Tailoring the interface using thiophene small molecules in TiO2/P3HT hybrid solar cells](https://www.iciq.org/wp-content/uploads/2014/03/Tailoring-the-interface-using_11990.gif)