Improved surface carrier recombination and efficiency for selective emitter N-type solar cells with Al-alloyed rear junction

In this paper, a fabrication process using well-arranged n(+) n/n(++) n front surface fields (FSFs) and a low temperature phosphosilicate glass (LTPSG) oxidation/etching for the emitter of n-type crystalline silicon solar cells is demonstrated. With an optimized phosphorus diffusion temperature of around 835 degrees C and a 6-min LTPSG oxidation, an effective lifetime for minority charge carriers, as long as 285.94 mu s and a high efficiency of 19.2% under AM 1.5 were obtained. This improved cell performance is attributed to the enhanced collection efficiency of excitons from FSFs and a good surface passivation from the oxidation/etching process to reduce surface recombination velocity.