Indium phosphide (InP) nanowires can serve as electron
superhighways that carry electrons kicked loose by photons of
light directly to the device’s electron-attracting electrode –
and this scenario could boost thin-film solar cell efficiency,
according to research recently published in NanoLetters. The new
design increases the number of electrons that make it from the
light-absorbing polymer to an electrode. By reducing electron-
hole recombination, the UC San Diego engineers have demonstrated
a way to increases the efficiency with which sunlight can be
converted to electricity in thin-film photovoltaics. Including
nanowires in the experimental solar cell increased the “forward
bias current” – which is a measure of electrical current – by
six to seven orders of magnitude as compared to their polymer-
only control device, the engineers found. The online journal
NanoLetters published this new work on polymer/nanowire hybrid
photovoltaicsin February 2008. “If you provide electrons with a
defined pathway to the ele