Interlaboratory comparison of photovoltaic performance measurements using CIGS solar cells

An interlaboratory test involving four PV laboratories was carried out to compare performance measurements using nonencapsulated CIGS solar cells. 15 samples were sorted according to their electrical parameters measured in the first lab and distributed to the three remaining ones, where the cells were remeasured. The comparison of the cells performance showed significant differences between the tested institutions, with variances in Voc, Jsc and FF. The method for contacting the cells, as well as the hardware and software used, were identified as the probable causes for the differences, suggesting that improvements in methodology and equipment, as well as constant monitoring, are necessary to assure the reliability of the measurements.