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Updated: Dec 13, 2025

Harvesting Solar Energy by Means of Charge-Separating Nanocrystals and Their Solids
Published on: August 23, 2012
Light and electric field induced unusual large-scale charge separation in hybrid semiconductor objects
Ambrose A Melvin1, Eric Lebraud, Patrick Garrigue
1Univ. Bordeaux, ISM UMR CNRS 5255, Bordeaux INP, ENSCBP, 33607 Pessac, France. kuhn@enscbp.fr.
Abstract:
Separation of electric charges is the most crucial phenomenon in natural photosynthesis, and is also extremely important for many artificial energy conversion systems based on semiconductors. The usual roadblock in this context is the fast recombination of electrons and holes. Here we demonstrate that the synergy of light and electric fields allows separating very efficiently electric charges over an unusually large distance in TiO2. The generated internal electric field can also be used to shuttle electrons simultaneously to the two opposite sides of a hybrid TiO2-polyaniline object. This counterintuitive behavior is based on the combination of the principles of bipolar electrochemistry and semi-conductor physics.
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