Large area solar cells with efficiency exceeding 19% in pilot series designed for conventional module assembling

Performance, reliability and cost are the key parameters in terms of wafer material, solar cell design and module fabrication to transfer a new solar cell concept into production. In this paper we present results based on pilot series of large area (156 mm x 156 mm wafer format) passivated emitter and rear solar cells on Czochralski grown boron doped wafers. Median efficiencies above 19% averaged over 50 wafer batches are received. These high-efficiency cells benefit from a passivated lowly doped industrial emitter on the front side, a seed and plate front side metallization and a dielectric passivated rear side using local contacts for rear side contacting. In order to optimize cell performance in a large-scale solar cell production a careful selection of the Cz silicon material is mandatory taking into account the electrical quality along the whole ingot. Solar cell results are presented before and after light-induced degradation using adjacent material along the complete ingot of different material supplier. Our passivated emitter and rear cells are conventionally solderable and can be integrated into a standard module assembling. The stability of our high-efficiency solar cells is shown by fabricating mini-modules that successfully pass standard climate chamber tests.