Anchoring cadmium chalcogenide quantum dots (QDs) onto stable oxide semiconductors for QD sensitized solar cells

Anchoring quantum dots (QDs) onto thermodynamically stable, large band gap oxide semiconductors is a very important strategy to enhance their quantum yields for solar energy conversion in both visible and near-IR regions. We describe a general procedure for anchoring a few chalcogenide QDs onto the titanium oxide layer. To anchor the colloidal QDs onto a mesoporous TiO ₂ layer, linker molecules containing both carboxylate and thiol functional groups were initially attached to TiO₂ layers and subsequently used to capture dispersed QDs with the thiol group. Employing the procedure, we exploited cadmium selenide (CdSe) and cadmium telluride (CdTe) quantum dots (QDs) as inorganic sensitizers for a large band gap TiO₂ layer of dye-sensitized solar cells (DSSCs). Their attachment was confirmed by naked eyes, absorption spectra, and photovoltaic effects. A few QD-TiO ₂ systems thus obtained have been characterized for photoelectrochemical solar energy conversion.