Collaboration between researchers at Bedair Group, North Carolina State University and the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), shows the high potential of quantum wells in multi-junction solar cells.
Multijunction solar cells based on four-junction III-V materials are currently the most efficient photovoltaic technology nowadays with 46% sun-light to electricity conversion efficiency under solar concentration. Next-generation multijunction solar cells will have five or more junctions with prospective efficiencies higher than 50%. The aim of this research was to develop the second highest energy cell in next-generation devices using InGaP-based quantum wells for 1.5 – 1.7 eV junctions.
The research groups improved the performance of InGaP-based quantum well solar cells through enhancing the solar cell design and using a gold reflector to enhance the sun-light to electricity conversion. The resulting paper, “100-period InGaAsP/InGaP Superlattice Solar Cell with Sub-bandgap Quantum Efficiency Approaching 80%” was recently published in the new issue of Applied Physics Letters (APL). The article was recently selected by Editor Xiuling Li as an APL Editor’s Pick and was highlighted on the journal homepage. The authors’ article is listed among most read papers in August/September 2017.
Islam Sayed, PhD Candidate in ECE advised by Prof. Salah Bedair and former graduate student intern at NREL, is lead author of the newly published research. In addition to Sayed, the authors of this research are Dr. Nikhil Jain, Dr. Myles Steiner, and Dr. John Geisz, all with NREL; and Prof. Salah Bedair, from NC State.
“There is a lot of interest in this promising direction for high efficiency photovoltaics,” John Geisz said. “This work can play a pivotal role in achieving higher solar cell efficiency,” Salah Bedair said.
The funding for the research came from the Department of Energy’s SunShot Initiative and National Science Foundation.