Aluminum Oxide Passivation Layer for Crystalline Silicon Solar Cells Deposited by Mist CVD in Open-Air Atmosphere

The surface passivation of Si wafer by AlO x thin films grown by mist CVD in an open-air atmosphere was studied with a view to improving the effect of high-performance c-Si solar cells. In AlO x thin film grown at a temperature above 400°C by mist CVD, the OH bonding did not remain in the film and the breakdown field ( E BD ) was over 6 MV/cm. In Si wafers passivated by AlO x thin films grown by mist CVD at growth temperature above 400°C, the negative fixed charge density ( Q f ) at the interface was higher than 10 12 cm -2 and the surface recombination velocity ( S eff ) was 44.4 cm/s. These results show that mist CVD, which is fundamentally an environmentally friendly technique, may be suitable for the fabrication of a passivation film on Si surfaces designed to improve the effect of high-performance c-Si solar cells.