A test bench for accelerated thermal ageing of III-V concentration solar cells using forward bias injection

Power production from solar photovoltaic systems is constantly increasing. In the last few years concentration photovoltaic (CPV) system using III-V multijunction cells appeared on the market, promising doubled efficiencies compared to traditional silicon PV solar panels. For CPV systems to be competitive on the market, they must be reliable to assure long-term operation. This paper presents the design and construction of a test bench for thermal cycling characterization of dense array receivers employing III-V multijunction cells mounted on a microchannel heat sink. Instead of a climatic chamber, the proposed test bench employs forward bias injection (FBI) to heat the cells, in order to better mimic on-field operating conditions. The experimental results of the accelerated ageing test are coherent with preliminary on-field trials, with a good agreement on the fault mechanism.