Development of a multi-source solar simulator for spatial uniformity and close spectral matching to AM0 and AM1.5

Results from ongoing development of spatial and spectral quality of RIT´s dual source solar simulator are presented. This simulator as designed qualifies as class A for both AM0 and AM1.5, depending on the filter set used. Measurements were made of spatial intensity uniformity, as well as spectral uniformity across the 300 mm diameter beam under calibrated AM0 conditions. The beam exhibits intensity non-uniformity across the 300 mm diameter test plane of 5.89%, though typically cells can be measured in a 10 cm × 10 cm central region of 1.13% non-uniformity. Spectral match and spectral mismatch values were calculated for specific spectral regions and device structures, respectively, which verified a close match to both AM0 and AM1.5G, especially in the region most commonly used for triple junction solar cells. Results of a set of ten Emcore BTJs measured at Emcore, Aerospace Corporation, NASA Glenn Research Center, and RIT, were compared. It was found that RIT´s simulator produced figures of merit such as V_OC, I_SC, fill factor, and efficiency, for these cells to within 2% of the other facilities.