Orbital Topology Controlling Charge Injection in Quantum-Dot-Sensitized Solar Cells

Summary, in English

Quantum-dot-sensitized solar cells are emerging as a promising development of dye-sensitized solar cells, where photostable semiconductor quantum dots replace molecular dyes. Upon photoexcitation of a quantum dot, an electron is transferred to a high-band-gap metal oxide. Swift electron transfer is crucial to ensure a high overall efficiency of the solar cell. Using femtosecond time-resolved spectroscopy, we find the rate of electron transfer to be surprisingly sensitive to the chemical structure of the linker molecules that attach the quantum dots to the metal oxide. A rectangular barrier model is unable to capture the observed variation. Applying bridge-mediated electron-transfer theory, we find that the electron-transfer rates depend on the topology of the frontier orbital of the molecular linker. This promises the capability of fine tuning the electron-transfer rates by rational design of the linker molecules.

• Author: Thorsten Hansen; Karel Zidek; Kaibo Zheng; Mohamed Qenawy; Pavel Chabera; Petter Persson; Tönu Pullerits
• Department/s: Chemical Physics; Computational Chemistry; NanoLund: Centre for Nanoscience
• Publishing year: 2014
• Language: English
• Pages: 1157-1162
• Publication/Series: The Journal of Physical Chemistry Letters
• Volume: 5
• Issue: 7
• Links: http://dx.doi.org/10.1021/jz5001193
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Theoretical Chemistry (including Computational Chemistry); Atom and Molecular Physics and Optics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1948-7185