Improved 750 °C epitaxial crystal silicon solar cells through impurity reduction

We characterize and improve epitaxial silicon films for solar cells grown by hot-wire chemical vapor deposition (HWCVD). The hot-wire filament temperature is found to affect the incorporation of impurities and the surface roughness of the films. Lowering the filament temperature leads to improved epitaxial films with lower impurities and smoother surfaces. Solar cells made with the improved material grown on low-cost silicon templates have open-circuit voltages (V_OC) ~600 mV and efficiency exceeding 10%.