A new method for accurate measurements of the lumped seriesresistance of solar cells

摘要

Measurements of the series resistance R_S are importantfor the localisation of dominant loss mechanisms in photovoltaicdevices. The new measurement technique presented in this work uses themeasured “J_SC-V_OC curve” of a solarcell as an approximation to the unknown R_S-corrected I-Vcurve and determines the “lumped series resistance” in darkand illuminated operating conditions (R_s.dark andR_s.light) from the voltage shift between the “J_SC-V_OC curve” and the dark and illuminated I-Vcurve, respectively. Owing to multidimensional effects in practicaldevices, the lumped series resistance depends on the operating conditionof the cell (i.e., dark or illuminated I-V measurements) and on thecurrent density flowing through the device. This work not only providesa new, powerful method for the determination of the lumped seriesresistance of photovoltaic devices, but also considerably improves thegeneral understanding of ohmic power loss effects in silicon solar cells