A new paper in the journal Environmental Science & Technology
assesses the requirements for scaling solar photovoltaic systems
to the terawatt levels needed to supply electric power on a
global scale. The authors identify iron pyrite, FeS2, as an
attractive but unconventional alternative: The raw materials for
pyrite aren’t scarce, and both the energy and monetary costs of
production could be low. In addition to having an outstanding
Klm value, pyrite is a strongly light-absorbing semiconductor
with a band gap in the right range for use in composite
materials systems for photovoltaics. This provides ample reason
to study and learn to control pyrite growth processes at the
atomistic level. Biological examples show that protein molecules
can guide crystal growth by selectively binding to crystal
surfaces and surface features, and pyrite can grow under
conditions that are compatible not just with proteins, but with
living organisms. Development of a good crystal-shaping
molecular toolkit could provide a route to