Cobalt sulfide counter electrode using hydrothermal method for quantum dot-sensitized solar cells

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 750; pp. 19 - 26
• Main Authors: Punnoose, Dinah, Kim, Hee-Je, Srinivasa Rao, S., Pavan Kumar, CH.S.S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2015
• Subjects: Cobalt sulfide; Counter electrode; Electro-catalytic activity; Hydro-thermal method; Quantum dot-sensitized solar cells; Electro-catalytic activity; Hydro-thermal method; Quantum dot-sensitized solar cells; Cobalt sulfide; Counter electrode
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2015.05.003

[Display omitted] •Efficient optimized CoS2 counter electrode for quantum dot sensitized solar cell.•Cobalt sulfide shows better charge transfer kinetics and superior electro-catalytic activity than the conventional Pt.•The power conversion efficiency of 2.27% with CoS2 CE based QDSSCs. Chalcogenides are potential alternatives to platinum (Pt) based counter electrode (CE). This study reports cobalt sulfide (CoS2) thin films as robust, high-performance, economical, earth-abundant CE for quantum dot-sensitized solar cells (QDSSCs). CoS2 thin film has been deposited on a fluorine-doped tin oxide substrate by a hydro thermal method using 3-mercapto propionic acid and used as an efficient CE for polysulfide redox reactions in quantum dot-sensitized solar cells (QDSSCs). CdS/CdSe-sensitized QDSSCs exploiting CoS2 CE improved short-circuit photocurrent density and fill factor. We attained 2.27% solar light-to-electricity conversion efficiency, a value higher than reaped with Pt CE (1.73%). Electrochemical measurements testified that CoS2 reveals high electro-catalytic activity towards polysulfide reduction, thus accelerating QDSSCs performance. CoS2 also showed stability at a working state for over 10h, resulting in highly reproducible performance, which is a serious challenge for solar cell.