FORMATION OF HIGH QUALITY BACK CONTACT WITH SCREEN-PRINTED LOCAL BACK SURFACE FIELD

摘要

A thin silicon solar cell having a back dielectric passivation and rear c ontact with local back surface field is described. Specifically, the solar c ell may be fabricated from a crystalline silicon wafer having a thickness fr om 50 to 500 micrometers. A barrier layer and a dielectric layer are applied at least to the back surface of the silicon wafer to protect the silicon wa fer from deformation when the rear contact is formed. At least one opening i s made to the dielectric layer. An aluminum contact that provides a back sur face field is formed in the opening and on the dielectric layer. The aluminu m contact may be applied by screen printing an aluminum paste having from on e to 12 atomic percent silicon and then applying a heat treatment at 750 deg rees Celsius.