Recent research in Israel suggests that plant-derived compounds could be a promising route for the realization of high-voltage organic optoelectronic devices. Experiments have shown that dried crystals made from the light–energy converters that drive photosynthesis in plants can generate extremely large photovoltages and electric fields when illuminated with light. Hila Toporik and co-workers from Tel Aviv University studied micrometre-thick samples made from plant photosystem I using Kelvin probe force microscopy. When illuminated with laser light at an intensity of 1.1 W cm−2, the samples generated voltages as large as 50 V and electric fields of the order of 100 kV cm−1. This field strength is estimated to be twice as large as that in the ferroelectric crystal LiNbO3:Fe and rivals the highest values reported for an inorganic material. The researchers say that the performance results from the superposition of aligned individual reaction centres, which induces a large net photoexcited dipole. They also say that these photosynthetic reaction centres have evolved over billions of years to become highly efficient light–energy converters that can operate with a quantum efficiency of almost 100%.
Rights and permissions
About this article
Cite this article
Graydon, O. High-voltage surprise. Nature Photon 6, 412 (2012). https://doi.org/10.1038/nphoton.2012.165
Published:
Issue Date:
DOI: https://doi.org/10.1038/nphoton.2012.165
