Towards 35% Efficient Concentrator Modules based on LPI Kohler Concentrators with External Confinement Cavities


Multijunction solar cells present a certain reflectivity on its surface that lowers its light absorption. This reflectivity produces a loss in electrical efficiency and thus a loss in global energy production for CPV systems. We present here an optical design for recovering this portion of reflected light, and thus leading to a system efficiency increase. This new design is based on an external confinement cavity, an optical element able to redirect the light reflected by the cell towards its surface again. We have proven the excellent performance of these cavities integrated in CPV modules offering outstanding results: 33.2% module electrical efficiency @Tcell = 25 °C@Tcell = 25 °C and relative efficiency and IscIsc gains of over 6%.

Publication type: 
Published in: 
7 International Conference on Concentrating Photovoltaic Systems Las Vegas, USA. 7TH INTERNATIONAL CONFERENCE ON CONCENTRATING PHOTOVOLTAIC SYSTEMS: CPV-7 Vol. 1407 p.p 109-112 doi:
Publication date: 
April 2011
CeDInt Authors: 
Other Authors: 
Yang Li