Co(SxSe1-x)2 Nanorods Arrays with Rhombus Cross-section Exhibiting High Catalytic Activity for Quantum dot Sensitized Solar Cells

Unique Co(SxSe1-x)(2) nanorod arrays (NRAs) with rhombus cross-section were grown on FTO by a Solid-Gas-Solid process and used for quantum-dot sensitized solar cells (QDSSCs). The composition of S/Se of the Co(SxSe1-x)(2) products could be facilely controlled by changing the molar ratios of S and Se powders. The as-prepared Co(SxSe1-x)(2) NRAs have high porosity, root mean square (27.3 nm) and small water contact angle (39.6 degrees), which benefits the electrolyte penetration and provides large active areas, leading to higher electrocatalytic activity and lower charge transfer resistance toward the reduction of S-n(2-) ions compared with Pt. In addition, the Co(SxSe1-x)(2) NRAs exhibits high reflectivity, which helps to improve the light-harvesting efficiency of the photoanode. Thanks to these structural advantages, when used as counter electrode, a high J(sc) of 16.37 mA cm(-2) was demonstrated, which leads to maximum power conversion efficiency (PCE) of 4.72% indicating similar to 55% improvement compared with the Pt based device (2.62%). (C) 2017 Elsevier Ltd. All rights reserved.