Large-scale synthesis of Cu sub(2)SnS sub(3) and Cu sub(1.8)S hierarchical microspheres as efficient counter electrode materials for quantum dot sensitized solar cells

• Published in: Nanoscale Vol. 4; no. 20; pp. 6537 - 6542
• Main Authors: Xu, Jun, Yang, Xia, Wong, Tai-Lun, Lee, Chun-Sing
• Format: Journal Article
• Language: English
• Published: 01.09.2012
• Subjects: CURRENT DENSITY; Electrode materials; Electrodes; Microspheres; MICROSTRUCTURES; Nanomaterials; Nanostructure; PARTICLES; Photovoltaic cells; Qunatum dots; SEMICONDUCTORS; Solar cells
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c2nr31724a

Exploration of new catalytic semiconductors with novel structures as counter electrode materials is a promising approach to improve performances of quantum dot sensitized solar cells (QDSSCs). In this work, nearly mono-disperse tetragonal Cu sub(2)SnS sub(3) (CTS) and rhombohedral Cu sub(1.8)S hierarchical microspheres with nanometer-to-micrometer dimensions have been synthesized respectively viaa simple solvothermal approach. These microspheres are also demonstrated as efficient counter electrode materials in solar cells using ZnO/ZnSe/CdSe nanocables as photoanode and polysulfide (S sub(n) super(2-)/S super(2-)) solution as electrolyte. While copper sulfide is regarded as one of the most effective counter electrode materials in QDSSCs, we demonstrate the CTS microspheres to show higher electrocatalytic activity for the reduction of polysulfide electrolyte than the Cu sub(1.8)S microspheres. This contributes to obvious enhancement of photocurrent density (J sub(SC)) and fill factor (FF). Power conversion efficiency (PCE) is significantly enhanced from 0.25% for the cell using a pure FTO (SnO sub(2):F) glass as counter electrode, to 3.65 and 4.06% for the cells using counter electrodes of FTO glasses coated respectively with Cu sub(1.8)S and CTS microspheres.