The invention discloses a
solar cell crystal silicon wafer phosphorus diffusion method. The method comprises the following steps: 1) a to-be-processed
crystal silicon wafer is placed in a
diffusion furnace, temperature is raised, and
nitrogen carrying a
phosphorus source, dry
oxygen and large
nitrogen are introduced, constant-source
diffusion is carried out; 2) introduction of the
nitrogen carrying the
phosphorus source is stopped, temperature is raised, the dry
oxygen and the large nitrogen are introduced to perform propelling; 3) the nitrogen carrying the phosphorus source and the dry
oxygen are introduced, and low-temperature diffusion is carried out; 4) the introduction of the nitrogen carrying the phosphorus source is stopped, and constant-temperature propelling is carried out; 5) temperature is raised, the nitrogen carrying the phosphorus source and the dry oxygen are introduced, and constant-source diffusion is carried out; 6) the introduction of the nitrogen carrying the phosphorus source is stopped, and oxygen-existing limited-source diffusion is performed; 7) temperature is lowered, the nitrogen carrying the phosphorus source, the dry oxygen and the large nitrogen are introduced, and cooling diffusion is carried out; and 8) temperature is lowered, and the
crystal silicon wafer is taken out from a boat. The
phosphorus diffusion method is simple and is easy to do, and the
phosphorus diffusion method is widely used; and
photoelectric conversion efficiency of the silicon wafer can be effectively improved through adoption of the method, electric performance of a
solar cell is improved, and the
phosphorus diffusion method is suitable for promotion and application.