Enhanced Front and Rear dielectric passivation for commercially grown Czochralski silicon for high efficiency solar cells

Commercial silicon solar cell efficiencies have been improving consistently over the last few years with the implementation of novel techniques. Along with larger wafer area and thinner substrates, low-cost processing of high efficiency solar cells can help achieve grid parity using crystalline silicon. In this work, large area cells were fabricated using conventional diffusion, oxidation and screen printing technologies. Several rear passivation schemes were compared to achieve low rear surface recombination velocities and combined with good front passivation to obtain cell V_OC of ~650 mV. Cells fabricated using these schemes resulted in an efficiency of 19.7% on 4 cm² cells and 18.5% on 62 cm² cells. Analysis and characterization of these cells reveals the possibility of achieving cell efficiencies greater than 19% on large area substrates.