Upright-standing SnO2 nanowalls: Fabrication, dual-photosensitization and photovoltaic properties

► Upright-standing SnO2 nanowalls aligned on FTO were grown by wet chemical method. ► Dual-photosensitization of SnO2 nanowalls with CdS quantum dots and Z907 dye. ► DSSCs utilizing CdS interlayer show 158% improvement in power conversion efficiency. ► CdS quantum dot layer minimizes charge recombination and improves light absorption.