Precision spectral response and I-V characterisation of concentrator cells

Characterisation of solar cells under one sun standard reporting conditions (SRC), according to the ASTM E894-83 standard, is performed at a high quality in many laboratories. To reach the same accuracy for concentrator cells, a measurement procedure must be developed which is both easy to apply and reliable in the results. In this work the authors present a new method, which gives correct results for solar cell efficiency measurements under concentrated light. The most critical point in the determination of the efficiency, the measurement of the simulator irradiance, is correctly solved and no assumptions like a linear relation between current and irradiance are necessary. With this new method, it is possible for the first time to obtain a complete and correct characterisation of concentrator solar cells both with spectral response and I-V characteristics. Using this measurement procedure, the authors determine the correct efficiencies for different samples of GaAs and Si concentrator cells and new physical results obtained from the interpretation of the spectral response under concentrated light