III−V compound semiconductors multijunction solar cells have been at the frontier of setting conversion efficiency records since early implementations of 2-junction architectures. Latest efficiency records are about 47% and correspond to 4-junction devices under concentrated solar illumination. The progress in developing low-bandgap GaInNAsSb materials latticed matched to GaAs and Ge, which are instrumental for further increasing the number of junctions towards better spectral utilization, is reviewed. Results concerning latticed matched solar cells with 5 and 6 junctions are presented and discussed in connection with possibility to reach a CPV efficiency of 50% and use in space solar power generation.
Prof. Mircea Guina leads the Optoelectronics Research Centre at Tampere University, Finland. He obtained the PhD degree in Physics from the Tampere University of Technology in 2002. Since then, he has been a constant contributor to the advance of optoelectronics technology using molecular beam epitaxy. His recent work has been directed to the development of novel semiconductor lasers, photonic integrated circuits, and high efficiency photovoltaics. He has an outstanding record in leading large-scale research projects extending from basic science to technology transfer, being a recipient of an ERC Advanced Grant for developing multi-junction III-V solar cells. He is a Fellow of the Optica and SPIE. Revevant links: https://www.linkedin.com/in/mircea-guina/ https://research.tuni.fi/orc/ch.tuni.fi/orc/