The Solar Energy Materials Research Group is led by Senior Scientist
Wladek Walukiewicz (PI) with Staff Scientists Joel Ager (co-PI) and Kin
Man Yu (co-PI). Senior Staff Scientist Zuzanna Liliental-Weber is also
associated with the program. The group is developing novel materials
that address the immediate need for sustainable, clean energy sources.
We are currently investigating both Group III-Nitride semiconductors as
well as highly-mismatched alloys for a number of energy-generating
applications. The following are a few examples:
Full-spectrum
Solar Cell
The
newly discovered narrow bandgap of InN Eg~0.7 has extended the spectral
range of the InGaN alloy system into the infrared region. That makes
InGaN an excellent material for high-efficiency multi-junction (tandem)
solar cells. As shown in the picture on the left, the bandgap of the
InGaN alloy matches the solar spectrum (Air Mass 1.5) almost perfectly
[1]. More...
"Multiband"
Solar Cell
The intermediate band acts as a “stepping stone,” allowing absorption
of photons at three different energy levels, corresponding to the three
different band gaps. In particular, low-energy photons are
captured that would pass through a conventional solar cell. More...