24.5% efficiency PERT silicon solar cells on SEH MCZ substrates and cell performance on other SEH CZ and FZ substrates

High-efficiency passivated emitter, rear totally diffused (PERT) and passivated emitter, rear locally diffused (PERL) cells have been fabricated on magnetically confined Czochralski (MCZ) silicon wafers supplied by SEH, Japan. One PERT MCZ cell demonstrated 24.5% energy conversion efficiency confirmed at Sandia National Laboratories under the standard 100 mW/cm2 global AM1.5 spectrum at 25°C. This is the highest ever reported efficiency for a silicon cell made on a non-FZ silicon substrate. A light boron diffusion in the PERT cell structure not only reduced the cell series resistance but also improved the cell open-circuit voltage. Other experimental results are also discussed concerning cells fabricated on other SEH CZ(Ga), CZ(B) and FZ substrates.