Solar Paint from TiO₂ Particles Supported Quantum Dots for Photoanodes in Quantum Dot–Sensitized Solar Cells

摘要

The preparation of quantum dot (QD)–sensitized photoanodes, especially the deposition of QDs on TiO_(2) matrix, is usually a time-extensive and performance-determinant step in the construction of QD-sensitized solar cells (QDSCs). Herein, a transformative approach for immobilizing QD on the TiO_(2) matrix was developed by simply mixing the as-prepared oil-soluble QDs with TiO_(2) P25 particles suspension for a period as short as half a minute. The solar paint was prepared by adding the TiO_(2)/QD composite in a binder solution under ultrasonication. The QD-sensitized photoanodes were then obtained by simply brushing the solar paint on a fluorine-doped tin oxide substrate followed by a low-temperature annealing at ambient atmosphere. Sandwich-structured complete QDSCs were assembled with the use of Cu_(2)S/brass as counter electrode and polysulfide redox couple as an electrolyte. The photovoltaic performance of the resulting Zn–Cu–In–Se (ZCISe) QDSCs was evaluated after primary optimization of the QD/TiO_(2) ratio as well as the thicknesses of photoanode films. In this proof of concept with a simple solar paint approach for photoanode films, an average power conversion efficiency of 4.13% (J _(sc) = 11.11 mA/cm~(2), V _(oc) = 0.590 V, fill factor = 0.631) was obtained under standard irradiation condition. This facile solar paint approach offers a simple and convenient approach for QD-sensitized photoanodes in the construction of QDSCs.