Development of p-type Silicon Heterojunction Solar Cells with 26.6% Efficiency

The development of high efficiency Si solar cells is seeing successful industrialization of carrier-selective and passivating contact technologies, including Tunnel Oxide Passivated Contact (TOPCon) and Silicon Heterojunction Technology (SHJ). Driven by cell technology innovation, the Si PV industry is making bold moves to see 26-27% efficiencies in mass production in the coming years. Undisputablly, Si wafer development provides strong support for the fast-upgrading cell technologies, and guarantees the technologies' deployment at affordable costs. To date, p-type Si wafer is dominating the market by 95% market share. However, a 5% to 50% uptaking of n-type Si wafer is predicted by ITRPV. One critical factor for this judgement is that the n-type Si solar cell efficiencies are leading ahead that of the p-type. It is well argued that the n-type Si wafer manufacturing can steadily ramp up given the demand, and the cost disadvantage can be alleviated to some extent with scaled production capacity. At the same time, the industry shall not ignore the inherent cost advantage of p-type wafers, and keep exploiting the possibilities to push up the p-type Si solar cell efficiency. In this work, we demonstrate that the p-type SHJ solar cell efficiency can reach 26.6%, which is just 0.2% behind of its n-type counterpart. This result establishes a solid foundation for further SHJ technology development on a cost-effective basis.