Solar cell sheet and heat treatment process thereof

摘要

Provided are a solar cell sheet and a heat treatment process thereof. The heat treatment process includes: a) sifting from solar cell sheets after printed and sintered cell sheets with conversion efficiency lower than 18% and filling factor thereof higher than 70%; b) performing low temperature annealing on the sifted cell sheets; c) sifting from the cell sheets after low temperature annealing cell sheets with lowered filling factor; d) re-sintering the sifted cell sheets; and e) sifting from the re-sintered cell sheets cell sheets with conversion efficiency lower than 18% and returning back to b) until most or all of the sifted meet demands. The low temperature annealing and re-sintering processes proceed cyclically, low temperature annealing can repair the defects in the substrate material, and the re-sintering process can repair the defects generated from low temperature annealing, and the two processes cooperate with each other and sifting can be performed repeatedly, greatly reducing the number of low efficient sheets and improving economic benefits.

主权项

1. A heat treatment process for solar cell sheets, comprising:
a) sifting out, from solar cell sheets on which printing and sintering are performed, cell sheets with conversion efficiencies lower than 18 percent and filling factors higher than or equal to 70 percent; b) performing low temperature annealing on the sifted cell sheets to improve the conversion efficiencies of the sifted cell sheets, wherein a temperature for the low temperature annealing is lower than that of the sintering; c) performing a sorting test on the cell sheets on which the low temperature annealing is performed, to sift out cell sheets for which the filling factors are decreased; d) re-sintering the cell sheets sifted out in step c) to increase the filling factors of the cell sheets, wherein a temperature for the re-sintering is same as that of the sintering; and e) performing a sorting test on the re-sintered cell sheets to sift out the cell sheets with the conversion efficiencies lower than 18 percent and returning to step b), until most or all of the sifted cell sheets have the conversion efficiencies higher than 18 percent and have the filling factors higher than or equal to 70 percent.