METHOD FOR FABRICATING SOLAR CELL

摘要

The present invention relates to a method for fabricating a solar cell, and the method is provided to improve the process efficiency by forming p-type emitter and n-type front-surface electric-field layer through a single diffusion process while omitting a diffusion preventive layer forming process on the front and back surfaces of a substrate. The method for fabricating a solar cell according to the present invention includes: a step of preparing a p-type crystalline silicon substrate; a step of depositing a BSG layer on the back surface of the substrate; a step of forming a p-type emitter in the back surface of the substrate by supplying gas which includes n-type impurity ions into a chamber and thermally processing while mounting the substrate in the chamber and forming an n-type front-surface electric-field layer; a step of depositing anti-reflection film on the front surface of the substrate; a step of forming a passivation layer on each of the front and back surfaces of the substrate; a step of forming an Al2O3 passivation layer on each of the front and back surfaces of the substrate using an atomic layer deposition method; a step of forming a capping layer on the passivation layer on the back surface of the substrate; a step of forming a contact hole which expose the p-type emitter of the substrate by removing a part of the capping layer and passivation layer of the back surface of the substrate; a step of coating conductive paste for back surface busbar electrode on the capping layer, coating aluminum paste on the entire back surface of the substrate to sufficiently fill the contact hole and coating conductive past for a front electrode on the front surface of the substrate; and a step of forming the back surface busbar electrode, front electrode and BSF layer by thermally processing the substrate. [Reference numerals] (S101) Preparing a p-type crystalline silicon substrate; (S102) Texturing - all the front surface/back surface or only the front surface; (S103) Forming a p-type emitter and n-type front-surface electric field layer; (S104) Forming an antireflection layer; (S105) Forming front surface passivation layer and back surface passivation layer - Al_2O_3 using an ALD process; (S106) Forming a capping layer; (S107) Forming a contact hole by partially removing the capping layer and back surface passivation layer; (S108) Printing back surface busbar electrode, front electrode and aluminum paste; (S109) Sintering - Forming back surface busbar electrode, front electrode and BSF layer