Indoor and outdoor comparison of CPV III–V multijunction solar cells

Concentrator III–V multijunction solar cells from seven vendors have been characterized via indoor flash test, outdoor on-sun test and spectral response. Most vendors have achieved similar efficiency in both indoor flash test and on-sun test. The relative difference among different cell vendors changes in two tests because of their different spectral responses and temperature coefficients. The spectral sensitivity of III–V multijunction cells leads to performance variation in the field that is not always well predicted by traditional indoor flash test or instantaneous on-sun tests. The results for different epitaxial designs and limitations of the test methodologies are presented. The comparative results lead to future design modifications for maximum energy output.