Students Design and Implement Fabrication Processes for Solar Cells and Improve Efficiency
Over 18 months in 2011 and throughout 2012, students from all the universities affiliated with the NSF-funded Engineering Research Center (ERC) for Quantum Energy and Sustainable Solar Technologies (QESST), which is headquartered at Arizona State University, designed and implemented solar-cell fabrication processes for state-of-the-art solar cells.
This Student Led Pilot Line now produces cells reaching 17.6% efficiency (commercial solar cells of this type range from 16.8% to 17.5% efficiency). Students running the pilot line rapidly improved the efficiency of the standard process through mini-research projects where groups of students focused on a particular topic and then integrated their ideas for the whole process. The effort, which resulted from interactions between undergraduate students, graduate students, and industry, provided important educational as well as research outcomes. The students also benefited from motivating and useful experiences. Participating graduates have gone on to work for companies involved in the pilot line and are collaboratively exploring starting solar-cell companies; undergraduates are being retained and in many cases are pursuing graduate school.
QESST is addressing many of the barriers facing increased implementation of solar cells, also known as photovoltaics (PV). QESST activities range from developing new technologies to teaching students about solar cells. Building a PV production line takes about 18 months, but “making” a new engineer takes at least four years. One particularly important aspect is teaching students how to make a solar cell, in a realistic setting, so they understand the technology as well as the challenges and issues for manufacturing.
The pilot line gives students opportunities to learn about complete solar-cell fabrication processes. Small student groups engage in research projects aimed at device improvement. The pilot line allows students to make full-size silicon screen printed solar cells, starting from a commercial silicon wafer. Students perform all processing, decide on tests to analyze devices, and initiate projects to improve cell performance. (See accompanying figure.) The pilot line integrates research, industry, and students, with company collaborations looking at new types of equipment to both increase efficiency and reduce cost. The pilot line also permits interaction among students from different universities, with over 10 U.S. universities sending students to make solar cells on the pilot line.