Degradation and Resurrection of Tunneling SiO2 Surface for Integration into Polysilicon Passivated Contact Silicon Solar Cells
Bill Nemeth1, David L. Young1, Matthew R. Page1, Vincenzo LaSalvia1, Dawn Findley1, Abhijit Kale1,2, San Theingi1, Steve P. Harvey1, Pauls Stradins1
1NREL, Golden, CO, United States
/2Colorado School of Mines, Golden, CO, United States

The duration and environment in which a tunneling SiO2 layer is permitted to age prior to doped polysilicon application critically impacts the resulting solar cell. This is due to accumulation of contaminants such as carbon and possible additional native oxide growth. We present evidence of aging degradation in lifetime structures as well as J-V measurements of metallized cells. We also present methods to resurrect an aged SiO2 layer with UV-O3 treatment prior to passivated contact formation to produce >21% polysilicon passivated contact solar cells.