High concentration photovoltaics (CPV) is the highest performance PV technology in the world due to the use of high-efficiency III-V multi-junction solar cells and the logarithmic increase of voltage with concentration. Recently, we have demonstrated a 4-junction solar cell with a record efficiency of 47.6%. This cell is based on an inverted GaInP/AlGaAs-tandem solar cell grown on GaAs substrate wafer-bonded to a GaInAsP/GaInAs tandem solar cell grown upright on InP substrate to form a monolithic 2-terminal device. In this talk we present results of this current champion solar cell structure and show how it was realized with the help of surface activated direct wafer-bonding. We will further give and outlook on the industrial roadmap for these high performance III-V multi-junction solar cells.
Dr. Oliver Höhn received his Ph.D. degree in physics in 2015 from Albert-Ludwigs-University, Freiburg, Germany, with a thesis on "Angle-selective photonic structures for optimized radiation balance in solar cells. ". He joined the Fraunhofer Institute for Solar Energy Systems ISE in 2008. There he is head of the group “III-V semiconductor technology” since 2022. He is part of the program committee of the conference “Physics, Simulation, and Photonic Engineering of Photovoltaic Devices XIII” at SPIE Photonics West and since 2023 his is associate editor of the OPTICA journal “Optics Express”. His main research interests include III–V multijunction solar cells, optical modeling and realization of micro- and nanostructured surfaces and optical modeling of high efficiency solar cells.More Details: http://s.fhg.de/hoehn