Constructing micro-flower modified porous TiO2 photoanode for efficient quantum dots sensitized solar cells

TiO2 photoanode as the light harvest skeleton and electron transport material plays a critical role in the photovoltaic performance of the quantum dots sensitized solar cells (QDSSCs). In this paper, a bilayer-structured film with micro-flower TiO2 as an overlayer and hierarchical porous TiO2 as an underlayer is fabricated. The hierarchical porous TiO2 film is synthesized by the virtue of foam and the TiO2 micro-flower is introduced by spin-coating method. This TiO2 micro-flower supplies more adsorption sites for CdSe quantum dots, thus leading to the enhanced light harvesting efficiency. The staggered structure between the anatase nanoparticle and the rutile micro-flower will facilitate the separation of electron-hole pairs and promote the injection process of electron. Consequently, the photovoltaic performance of QDSSCs based on the TiO2 micro-flower modified photoanode is about 43% higher than that of the bare porous TiO2 photoanode.