Project Focuses on Lowering the Cost of Solar Power
Solar power research in the Materials Science and Engineering Department has received another boost thanks to a new $350,000 National Science Foundation grant to work on “Two-Stage Buffer Layers for Solar Power in a InGaP - Si Double Junction Cell.”
"Reviewers judged the concept of using very thin Ge and graded buffer interfaces to make high efficiency (30%) III-V/c-Si solar cells on relatively inexpensive Si substrates as potentially transformative research," said Dr. Wiley Kirk, principal investigator for the project.
His co-investigators on the three-year project are Dr. Christopher Hinkle and Dr. Robert Wallace.
According to the project's abstract, "The objective of this project is to monolithically integrate In0.50Ga0.50P on Si wafer substrates by using a thin nucleation layer of Ge followed by a metamorphic buffer comprised of step-graded InxGa1-xP. The thin 3 ML Ge layer will provide a nucleation template for the step-graded InxGa1-xP as well as provide a coherent, pseudomorphic interface at the top surface of the Si bottom p-n junction. We will be able to solve two key materials science issues together: i) provide nucleation for III-P semiconductors that normally do not interface well directly with Si atoms and ii) provide a clean interfacial layer that can electrically passivate the n-type Si emitter layer of the Si bottom p-n junction."
The National Academy of Engineering's top engineering challenge for the 21st century is to make solar energy economical by overcoming the barriers to widespread solar power generation. "Our project provides a way to address this societal grand challenge," Kirk said.
Two graduate students will work on the project, which will also enable a teacher from a local school district to participate in a six-week summer program that will engage the teacher with the research and support development of classroom materials for teaching future scientists, engineers and technologists.