In:
Science, American Association for the Advancement of Science (AAAS), Vol. 328, No. 5985 ( 2010-06-18), p. 1543-1547
Abstract:
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 (TiO 2 ) 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-TiO 2 interface excited coherent vibrations of the TiO 2 surface atoms, whose motions could be followed in real time.
Type of Medium:
Online Resource
ISSN:
0036-8075
,
1095-9203
DOI:
10.1126/science.1185509
Language:
English
Publisher:
American Association for the Advancement of Science (AAAS)
Publication Date:
2010
detail.hit.zdb_id:
128410-1
detail.hit.zdb_id:
2066996-3
detail.hit.zdb_id:
2060783-0
SSG:
11
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