Light soaking effects on photovoltaic modules: Overview and literature review

Device performance under extended duration illumination is an essential characterization step for any PV technology, because light exposure can produce a variety of effects which influence the determination of both initial and long-term stabilized device performance. We present an overview of PV light soaking behavior based on a literature review of light soaking effects on commercial PV module technologies, including a-Si/μc-Si, CdTe, CIS/CIGS, and c-Si. We address the physical mechanisms of light-induced changes in each PV technology, short-and long-term light-induced effects, and current literature knowledge on PV module preconditioning for accurate power output determination. We highlight common themes and identify desirable attributes of equipment for PV module light soaking characterization and test.