Conjunction of macroporosity and NH4F treatment for improved performance of TiO2 photoanode in quantum-dot sensitized solar cells

Macropores(MPs) are generally used to enhance the scattering of light inside mesoporous TiO2 photoanodes used for dye sensitized solar cells (DSSCs) as well as quantum-dot sensitized solar cells (QDSSCs). Despite of an increase in the scattering characteristics of TiO2 photoanode, the incorporation of MPs beyond an optimum level results a decrease in the performance of DSSCs or QDSSCs which is credited to lowering of dye or QD loading inside TiO2 photoanode. In this attempt, we have concurrently employed the scattering proficiency of higher incorporation of MPs (similar to 30wt%) and an apposite NH4F-treatment assuring a significant increase in QD loading, resulting in a notable improvement in photovoltaic performance of PbS-based QDSSCs. Nearly 18% increase in power conversion efficiency of QDSSCs was obtained which was attributed to increase in photocurrent density (J(SC)) from 13.04 to 15.18mA/cm(2).