Study on the blocking effect of a quantum-dot TiO2 compact layer in dye-sensitized solar cells with ionic liquid electrolyte under low-intensity illumination

Abstract In this study, ultrasmall and ultrafine TiO 2 quantum dots (QDs) were prepared and used as a high-performance compact layer (CL) in dye-sensitized solar cells (DSCs). We systematically investigated the performance of TiO 2 CL under both low-intensity light and indoor fluorescent light illumination and found that the efficiency of DSCs with the insertion of optimal TiO 2 QDs-CL was increased up to 18.3% under indoor T5 fluorescent light illumination (7000 lux). We clarified the controversy over the blocking effect of TiO 2 CL for the efficiency increment and confirmed that the TiO 2 QDs-CL performed significantly better under low-intensity illumination due to the efficient suppression of electron recombination at the FTO/electrolyte interface. We, for the first time, demonstrate this potential for the application of the DSCs with TiO 2 QDs-CL in the low-intensity light and indoor fluorescent light illumination.