Reliability of Tandem Solar Cells and Modules: What's Next? Article No. 100062

Tandem photovoltaic (PV) technology development has gained momentum in the last few years. This has been motivated by a need to push module efficiencies beyond what is theoretically capable through single-junction technologies to further accelerate total global PV deployment. Significant advances have been made on lab-scale devices, with multiple material systems achieving efficiencies over 30% in the last few years. All of the record efficiencies have been come from laboratory-scale devices, with areas of 1cm$^2$ or less. Despite these high efficiencies, reasonable service lifetimes need to be achieved to compete with the levelized cost of energy (LCOE) of traditional PV technologies to become become commercially viable. Without reasonable service lifetimes tandem technology cannot succeed because it won't deliver the necessary returns compared to traditional Si or CdTe single junction technologies.