20.3% MWT Silicon Heterojunction Solar Cell—A Novel Heterojunction Integrated Concept Embedding Low Ag Consumption and High Module Efficiency

In this paper, we present the successful integration of a silicon heterojunction (HJ) solar cell with metal wrap through (MWT) architecture. This MWT-HJ cell and module technology combines all the advantages of the individual concepts. With this contribution, we demonstrate a record device efficiency of 20.3% achieved using commercial n-type Cz 6-in wafers. To our knowledge, this is the first time cell results for MWT-HJ architecture have been reported. We put this result in perspective, providing a solution for the reduced conductivity of low-temperature silver pastes used for HJ cell fabrication. We propose a method to further increase the solar cell performance up to 4%
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, together with a 50% cost of ownership reduction of the front contact silver, including via and conductive adhesive at the rear. This is possible solely by the optimization of the front metal grid in this MWT structure predicting efficiencies above 21%. MWT-HJ is a fully low-temperature integrated cell and module concept and is also compatible with next-generation thinner wafers.