High Lifetime Ga-doped Cz-Si for Carrier-Selective Junction Solar Cells

Industrial mass production of solar cells is at a transition towards carrier selective junction solar cells with passivating contacts such as TOPCon, POLO or HJT. At the same time many manufacturers consider switching from p-type Cz-Si to n-type Cz-Si wafers. This contribution indicates that Ga-doped p-type Cz-Si material is still a viable option for the new type of devices while giving an opportunity to benefit from lower wafer cost. We report minority carrier diffusion lengths that are an order of magnitude larger than the thickness of the studied HJT and TOPCoRE devices. Stability aspects for operation in the field are discussed. Best TOPCoRE solar cells on Ga doped CZ-Si show a 0.2% higher efficiency than their co-processed n-type counterparts.