Quantum-dot-sensitized solar cells: Understanding linker molecules through theory and experiment

Authors

Johannes T. Margraf, University of Erlangen-Nuremberg
Andres Ruland Palaia, University of WollongongFollow
Vito Sgobba, University of Erlangen-Nuremberg
Dirk M. Guldi, University of Wollongong
Timothy Clark, Friedrich-Alexander University, University of PortsmouthFollow

RIS ID

105456

Publication Details

Margraf, J. T., Ruland , A., Sgobba, V., Guldi, D. M. & Clark, T. (2013). Quantum-dot-sensitized solar cells: Understanding linker molecules through theory and experiment. Langmuir: the ACS journal of surfaces and colloids, 29 (7), 2434-2438.

Abstract

We have investigated the role of linker molecules in quantum-dot-sensitized solar cells (QDSSCs) using density-functional theory (DFT) and experiments. Linkers not only govern the number of attached QDs but also influence charge separation, recombination, and transport. Understanding their behavior is therefore not straightforward. DFT calculations show that mercaptopropionic acid (MPA) and cysteine (Cys) exhibit characteristic binding configurations on TiO2 surfaces. This information is used to optimize the cell assembly process, yielding Cys-based cells that significantly outperform MPA cells, and reach power conversion efficiencies (PCE) as high as 2.7% under AM 1.5 illumination. Importantly, the structural information from theory also helps understand the cause for this improved performance.