The invention discloses a
boron diffusion method of a
crystalline silicon solar cell, wherein the method comprises the following steps: (1), arranging a
silicon chip subjected to felting and cleaning processes in a
diffusion furnace
pipe, heating to 900 DEG C to 1100 DEG C, introducing
nitrogen, a relatively large amount of
boron source and
oxygen, and performing
boron diffusion, wherein the diffusion time is 5min to 60min; (2), keeping the temperature in the step (1), introducing
nitrogen, a relatively small amount of boron source and
oxygen, and performing
boron diffusion, wherein the diffusion time is 15min to 80min; (3), keeping the temperature in the step (1) or heating to 910 DEG C to 1100 DEG C, introducing
nitrogen, a relatively large amount of boron source and
oxygen, and performing
boron diffusion, wherein the diffusion time is 2min to 30min; and (4) finishing the diffusion process. With the adoption of the
boron diffusion method, the high
impurity concentration is formed within small depth range of the surface of the
silicon chip, so as to be beneficial to forming of excellent
ohm contact; the
impurity concentration of the large depth range of a
diffusion layer is reduced; the
auger recombination and combination generated by nudged defect are reduced, the minority
carrier lifetime is prolonged, so the property of the
cell is enhanced.