One kind of tunneling silicon oxynitride passivation layer in contact with a solar cell and its preparation method

The present invention provides a solar cell comprising a silicon wafer, a passivation tunneling layer, a doped thin film silicon layer, the passivation layer is disposed between the tunneling silicon film and the doped silicon layer, wherein the passivating tunneling oxide layer is a silicon / silicon oxynitride gradient laminate silicon oxynitride / silicon nitride stack gradient, a silicon oxide / silicon oxynitride / silicon nitride stack of one gradient; the nitrogen-doped silicon oxide aza-doped silicon oxide or silicon nitride oxide; the silicon oxide / silicon oxynitride gradient laminate silicon oxynitride / silicon nitride stack gradient, a silicon oxide / silicon oxynitride / silicon nitride stack gradient nitrogen concentration gradient decreases from side to side away from the silicon wafer. Since silicon nitride and silicon oxide tunneling barrier lower, the present invention tunneling through a passivation layer may be the premise of ensuring efficient tunneling tunneling appropriate relaxation thickness of the passivation layer, thereby facilitating reducing passivation tunneling layer having holes, and reduce the speed of the composite leakage current, widening the process window and improved process stability.