Статья

Hot-Electron Transfer from Semiconductor Nanocrystals

William A. TisdaleDepartment of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USAKenrick J. WilliamsDepartment of Chemistry and Biochemistry, University of Texas, Austin, TX 78712, USABrooke A. TimpDepartment of Chemistry, University of Minnesota, Minneapolis, MN 55455, USADavid J. NorrisDepartment of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USAEray S. AydilDepartment of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USAXiaoyang ZhuDepartment of Chemistry and Biochemistry, University of Texas, Austin, TX 78712, USA

2010en

ABI

Аннотация

In typical semiconductor solar cells, photons with energies above the semiconductor bandgap generate hot charge carriers that quickly cool before all of their energy can be captured, a process that limits device efficiency. Although fabricating the semiconductor in a nanocrystalline morphology can slow this cooling, the transfer of hot carriers to electron and hole acceptors has not yet been thoroughly demonstrated. We used time-resolved optical second harmonic generation to observe hot-electron transfer from colloidal lead selenide (PbSe) nanocrystals to a titanium dioxide (TiO2) electron acceptor. With appropriate chemical treatment of the nanocrystal surface, this transfer occurred much faster than expected. Moreover, the electric field resulting from sub-50-femtosecond charge separation across the PbSe-TiO2 interface excited coherent vibrations of the TiO2 surface atoms, whose motions could be followed in real time.

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Идентификаторы

DOI: 10.1126/science.1185509

Цитирования и источники

Цитирований: 2Использованных источников: 0

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