Investigation of solar cell overheating under radiation of ultrahigh intensity

In the article, the results of investigation of thermal properties of photovoltaic (PV) cells for high-concentrated optical radiation under different conditions of heat removal are presented. Single-junction AlGaAs-GaAs cells under the investigation were soldered either on copper heat sinks or on plates of metalized AlN ceramics. To determine thermal properties, a procedure which allowed measuring temperature of cell p-n junctions in indoor conditions while simulating thermal processes arising during operation of the cells in outdoor conditions has been used. Simulation of thermal processes occurring in the cells was performed by passing current through them in the forward direction. The p-n junction overheating temperature was determined by comparing direct voltage drops in the cells I-V characteristics recorded during fast switching-on or switching-off of a device under different conditions of heat removal. To estimate the accuracy of the proposed method, cells overheating under laser illumination has been studied.