Filled with
suitable organic polymers the highly porous germanium nanofilm becomes
a hybrid solar
cell – Photo: Andreas Battenberg
Nanostructured germanium for portable photovoltaics and
battery electrodes
(December 7, 2015) Using
a new procedure researchers at the Technical University of Munich (TUM) and the
Ludwig Maximillians University of Munich (LMU) can now produce extremely thin
and robust, yet highly porous semiconductor layers. A very promising material –
for small, light-weight, flexible solar cells, for example, or electrodes
improving the performance of rechargeable batteries.
The coating on the wafer that Professor Thomas Fässler,
chair of Inorganic Chemistry with a Focus on Novel Materials at TU Munich,
holds in his hands glitters like an opal. And it has amazing properties: It is
hard as a crystal, exceptionally thin and – since it is highly porous – light
as a feather.
Electronmicroscopical
image of the germanium-structure after removal
of the polymer
templates – Image: Katia Rodewald / TUM
By integrating suitable organic polymers into the pores of
the material, the scientists can custom tailor the electrical properties of the
ensuing hybrid material. The design not only saves space, it also creates large
interface surfaces that improve
“You can imagine our raw material as a porous scaffold with
a structure akin to a honeycomb. The walls comprise inorganic, semiconducting
germanium, which can produce and store electric charges. Since the honeycomb
walls are extremely thin, charges can flow along short paths,” explains
Fässler.