Stepwise cosensitization through chemically bonding organic dye to CdS quantum-dot-sensitized TiO_2 electrode

摘要

An organic dye (JK218) with thiol moiety as an anchoring group was synthesized and explored to assemble a cosensitized TiO_2 electrode in combination with an inorganic CdS quantum-dot. Due to the selective adsorption of JK218 on the surface of CdS through thiol group, the developed cosensitized electrode demonstrates cascade architecture with CdS coating on TiO_2 while JK218 functions as a covering on CdS. Most importantly, the energy levels of the TiO_2-CdS-JK218 electrode were also found to be stepwise aligned, which accordingly makes electrons efficiently inject from JK218 to CdS under illumination and finally collect to TiO_2. This constructed cosensitized electrode with an organic sensitizer (JK218) and an inorganic quantum-dot (CdS) being selectively bonded together is expected to be valuable for the interface design of next generation solar cells.