Preparation of hollow Co9S8 nanoneedle arrays as effective counter electrodes for quantum dot-sensitized solar cells

Abstract

Hollow Co₉S₈ nanoneedle arrays directly grown on fluorine-doped tin oxide (FTO) transparent conducting substrates were successfully prepared using a simple sacrificial template method. The performances of CdS/CdSe quantum dot-sensitized solar cells (QDSCs) employing such Co₉S₈ counter electrodes were remarkably improved compared to those using conventional Pt counter electrodes, primarily due to their higher electrocatalytic activity in the reduction of polysulfide electrolytes.