The award that opens doorsDonnerstag, 02.08.2012 11:49
Dr. Christian Reimann earned the SolarWorld Junior Einstein Award for his dissertation in 2010. He still works in crystal growing at the Fraunhofer Institute for Integrated Systems and Device Technology (IISB) in Erlangen.
Sharing the stage with a Nobel Prize winner, being applauded by 400 scientists and heads of companies from around the world, and receiving an award for your own scientific achievement is something most doctoral candidates can only dream of..
The dream came true for Dr. Christian Reimann from the Fraunhofer Institute for Integrated Systems and Device Technology (IISB) in Erlangen. In 2010, he won the SolarWorld Junior Einstein Award, one of the most renowned awards for young scientists in the field of photovoltaics. Since 2006, the award has been bestowed on young scientists whose dissertation or thesis has made a significant contribution to the advancement of solar power technology. Not only does the award come with a € 5000 cash prize, it also offers the winner a bit of celebrity the industry.
Reimann chose a hot topic for his dissertation: he researched impurities in the 1450°C silicon melt, which is created at the beginning of the photovoltaic production chain. Highly pure silicon, the base material of solar modules, is melted in a crystallization furnace to enable it to cool and solidify under controlled conditions. The resulting silicon ingot is then sliced thinly into wafers, which then become solar cells. “Foreign elements like carbon dioxide, oxygen, and nitrogen from the coating on the casting mold or the graphite-clad furnace contaminate the melt,” explains Reimann. Only a small number of these particles are incorporated into the silicon crystal lattice during crystal growth. The rest remain in the liquid phase of the melt. When their concentration is too high, hard crystallites, SiC and Si3N4, form in the silicon melt, which cause problems later when the wafers are sawn. Later, these material defects can even cause short circuits in the solar cell. “My dissertation focused on why these phases form and how they can be prevented,” explains Reimann.
His solution: the locally high concentrations of foreign atoms can be prevented by thoroughly mixing the melt. You can try out the trick he uses for yourself. Just as cream moves along the surface of coffee when you blow on it, the silicon melt can be agitated by mixing it using injecting gases. Unlike coffee drinkers, Reimann doesn’t blow normal air. He uses the noble gas, argon.
Reimann’s advisor at the Fraunhofer IISB was so impressed by Reimann’s outstanding work that he recommended to apply for the SolarWorld Junior Einstein Award. “When I got the call that I had won, I cheered so loudly on the phone that everyone in the hall could hear,” he recalls.
Reimann is the first researcher who works with crystallization to be recognized, and he is delighted for his colleagues as well. “The award has given crystal growth more importance in the photovoltaics industry and raised awareness of its enormous impact on material quality.” He is also delighted about the appreciation of his four-and-a-half years of work and the emotional dedication he put into the project: “You invest a lot of time in trying to grow crystals since it’s a tedious process and the technology is difficult to use. Working with high temperatures, hot melts, and gases can definitely keep you up at night. But enthusiasm for crystal growth and scientific curiosity always serve as fodder for good ideas,” says Reimann, who is now group manager at the Fraunhofer IISB. The Junior Einstein Award and the press release announcing his win have increased his recognition in the scientific community, he says. “The award can open additional doors for a young scientist.”
Today he shares his enthusiasm for photovoltaics by serving as an advisor to his students and scientific employees,encouraging them through their own laborious doctoral projects. He continues to work with intensity on own projects, which tend to be practical in nature: “The focus is on crystal growth. My work involves improving material quality by improving crystal growth processes, which can increase the efficiency of subsequent solar cells and also affect the reduction in production costs per watt peak.”
2012 SolarWorld Junior Einstein Award
Applications can be submitted by June 29 at: www.einstein-award.de.
Scientific theses and dissertations on photovoltaics (Bachelor’s, Master’s or “Magister” theses, and doctoral dissertations) will be considered.
Award ceremony in Frankfurt on September 25, 2012