Influence of Chemical Polishing on Performances of Silicon Heterojunction Solar Cells

Aiming to avoid the local epitaxial growth of amorphous silicon films in the pyramidal valleys of the textured silicon wafers, a chemical polishing mixture named CP133 is used to polish the textured crystalline silicon (c-Si) surfaces. The research results show that the morphologies of the pyramidal valleys change from V shape to U shape, which clearly improves the passivation effect at the hydrogenated amorphous silicon/crystalline silicon interface. When the temperature is lower than 30 degrees C , the solution is difficult to react with the crystalline silicon. However, the problem can be solved by the increase of the solution temperature up to 35 degrees C . The performance of the solar cells is relatively good when the polishing time is 30 s and the NaOH texturing solution has a mass fraction of 1%.