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Rafael Jaramillo, Ph.D.

MIT physicist transitions to renewable energy with hopes of building a world-leading research group

For Rafael Jaramillo, Ph.D., who received his doctoral degree in physics, being awarded a U.S. Department of Energy Office of Energy Efficiency and Renewable Energy (EERE) Postdoctoral Research Award was instrumental in helping him transition from a specialization in physics to renewable energy. The EERE Postdoctoral Research Awards are administered by the Oak Ridge Institute for Science and Education, which is managed by ORAU through a contract with the DOE.

“Ever since undergrad I wanted to work in renewable energy, but I was also very interested in physics,” Jaramillo explained. “I ended up in a physics doctoral program at the University of Chicago, which did not put much emphasis on real-world applications. After graduation I wanted to redirect my career towards energy-related research, which led me to postdoctoral positions first at Harvard and then to work with Tonio Buonassisi at the MIT Photovoltaics Laboratory (PVLab), where I received the EERE award. I finally feel like I am putting together the various pieces – scientific background, experience with semiconductors and devices, general knowledge of energy issues, and specific knowledge of the solar energy industry to conduct research in an area that makes a difference.”

Rafael Jaramillo

Rafael Jaramillo, Ph.D., researches how to improve the efficiency of solar energy cells, through the use of materials such as tin sulfide and copper zinc tin sulfide. (Photo courtesy of Vera Steinmann, MIT)

Jaramillo’s current research in the MIT PVLab covers two projects focusing on improving the efficiency of solar cells based on tin sulfide (SnS) and copper zinc tin sulfide (CZTS). Together with a large team from MIT and Harvard University, he is making solar cells by replacing typical materials with SnS. If successful, this project will result in solar cells that are less expensive and can be manufactured in much larger quantities than present-day technology. This MIT-Harvard collaboration currently holds the world record for SnS solar cell performance, and Jaramillo expects to see continued improvement in the months ahead.

With his CZTS research, Jaramillo is using X-ray spectroscopy to understand the ways in which the atoms in CZTS films can become disordered, and how these mechanisms can be harnessed to improve the performance and cost of solar cells. This project is a collaborative effort between MIT and the National Renewable Energy Laboratory. The X-ray experiments are performed at synchrotron user facilities sponsored by the DOE, such as the Advanced Photon Source in Illinois and the Stanford Synchrotron Radiation Laboratory in California.

The common goal for Jaramillo’s research is to advance the use of safe and inexpensive materials that can improve solar energy technology and thus create additional opportunities to reduce the carbon output of society. To him, advancing renewable energy research is critically important for the future prosperity of the U.S. and the world.

For Jaramillo, the most valuable aspect of the EERE award has been the intellectual freedom and flexibility it gives to pursue renewable energy research. “As somebody relatively new to renewable energy research, it has been a great pleasure to have the freedom to think about and explore various lines of inquiry, which is not realistic under a conventional research grant,” he said. “The award has allowed me to gain the experience I needed, so I can now become an effective researcher in renewable energy.”

In 2015 Jaramillo will begin his first faculty position as an assistant professor in the Department of Materials Science and Engineering at MIT. He is excited about the prospect of leading his own research group and also learning together with his students. Jaramillo’s hope for the future is to establish a world-leading research group focused on the possibilities where materials sciences, renewable energy and semiconductor physics intersect.