L. Kronik et al., SURFACE-STATES AND PHOTOVOLTAIC EFFECTS IN CDSE QUANTUM-DOT FILMS, Journal of the Electrochemical Society, 145(5), 1998, pp. 1748-1755
Citations number
44
Categorie Soggetti
Electrochemistry,"Materials Science, Coatings & Films
Photovoltaic effects in CdSe quantum dot (QD) films have been studied
using surface photovoltage spectroscopy and complementary methods. The
results show that, contrary to previous studies, nonnegligible electr
ic fields can exist in QD films. As a result, driftlike currents must
be considered, in addition to the well-known diffusionlike currents. H
owever, it is found that the specific case of photovoltage sign revers
al, observed after etching highly quantized CdSe QD films, is governed
by diffusionlike transport. The latter is highly influenced by prefer
ential trapping of one type of charge carrier. The preferential trappi
ng is shown to be surface localized and is strongly ambient dependent.
It is shown that the photovoltaic properties of these CdSe QD films a
re dominated by their surface state distribution.