Patent ID: 9337359
Filing Date: 2016-05-10
CPC Classification: H01L,Y02E,Y02P

Claim Text:
1. A solar cell, comprising: a semiconductor substrate of a first conductive type; an emitter region containing impurities of a second conductive type opposite to the first conductive type, and being positioned at the semiconductor substrate of a first conductive type; a first electrode connected to the emitter region; a passivation layer positioned on the semiconductor substrate, and having a contact hole; a back surface field region positioned at the semiconductor substrate, and exposed by the contact hole; a dopant layer containing impurities of the first conductive type, and being directly positioned on the passivation layer and contacting the back surface field region through the contact hole; and a second electrode positioned on the dopant layer, wherein the dopant layer contains the impurities of the first conductive type and is entirely positioned between the passivation layer and the second electrode, wherein the dopant layer comprises a first surface facing the semiconductor substrate and a second surface opposite the first surface, wherein the first surface of the dopant layer directly contacts an entire surface of the passivation layer that faces towards the dopant layer, and the entire second surface of the dopant layer directly contacts the second electrode, wherein a composition of the dopant layer, which contains boron (B), is different from a composition of the second electrode, which contains aluminum (Al), wherein the contact hole is filled with a mixture comprising a material of the dopant layer and a material of the second electrode, wherein the mixture is a mixture (B+Al) of boron (B) and aluminum (Al), and wherein the passivation layer is entirely and directly formed on a back surface of the semiconductor substrate, except for the back surface field region exposed by the contact hole.