Record-Efficiency n-Type and High-Efficiency p-Type Monolike Silicon Heterojunction Solar Cells with a High-Temperature Gettering Process

Abstract

We report independently confirmed 22.15% and record 22.58% power conversion efficiencies for thin (130–140 μm) p-type and n-type monolike Si solar cells, respectively. We comparatively assessed advanced n-type and p-type monolike silicon wafers for potential use in low-cost, high-efficiency solar cell applications by using phosphorus diffusion gettering for material-quality improvement and silicon heterojunction solar cell fabrication for assessment of performance in high-efficiency photovoltaic device architecture. We show that gettering improves material quality and device properties significantly, depending on the type of doping (n-type or p-type), wafer position in the ingot, drive-in temperature, and cooling profile. Owing to the high open circuit voltage (725 mV), the record n-type solar cell also represents the highest reported solar cell efficiency for cast silicon to date.