Lattice-Matched Solar Cells With 40% Average Efficiency in Pilot Production and a Roadmap to 50

• Published in: IEEE journal of photovoltaics Vol. 3; no. 1; pp. 542 - 547
• Main Authors: Aiken, D., Dons, E., Sang-Soo Je, Miller, N., Newman, F., Patel, P., Spann, J.
• Format: Journal Article
• Language: English
• Published: IEEE 01.01.2013
• Subjects: Computational modeling; III-V multijunctions; Junctions; Lattice matched; Materials; metamorphic; Photonic band gap; Photovoltaic cells; Predictive models; Production
• ISSN: 2156-3381; 2156-3403
• DOI: 10.1109/JPHOTOV.2012.2226142

A commercial lattice-matched InGaP/InGaAs/Ge solar cell has reached an average efficiency of 40% at 500 kW/m 2 . The design changes that lead to this result are discussed. These data are complemented with a presentation of the latest new solar cell development results from the laboratory. Inverted metamorphic multijunction (IMM) solar cells have been prototyped with 42.4% efficiency at 325 suns for concentrator applications and 33.6% efficiency at 1 sun AM0 for space applications. Six subcell devices are now under development. These results are used, along with other experimental data and other industrial constraints, as input to a computer model to predict what practical efficiency might be achievable with this device approach. The computer model suggests that 45% and 50% efficiencies are technologically feasible with a three-junction and five-junction device, respectively, at an irradiance of 500 kW/m 2 and 25 °C using known materials, device architectures, and manufacturing methods.