Solar cell and method for manufacturing the same

Abstract

A solar cell and a method for manufacturing the same are disclosed. The solar cell may include a substrate, an emitter layer positioned at a first surface of the substrate, a first anti-reflection layer that is positioned on a surface of the emitter layer and may include a plurality of first contact lines exposing a portion of the emitter layer, a first electrode that is electrically connected to the emitter layer exposed through the plurality of first contact lines and may include a plating layer directly contacting the emitter layer, and a second electrode positioned on a second surface of the substrate.

1 . A solar cell comprising:
 a substrate including a uniform first surface;   an emitter layer positioned at the first surface of the substrate;   a first anti-reflection layer positioned on a surface of the emitter layer, the first anti-reflection layer including a plurality of first contact lines exposing a portion of the emitter layer;   a first electrode electrically connected to the emitter layer exposed through the plurality of first contact lines, the first electrode including a plating layer directly contacting the emitter layer; and   a second electrode positioned on a second surface of the substrate.   
     
     
         2 . The solar cell of  claim 1 , wherein the first electrode has an aspect ratio of about 0.83 to 1. 
     
     
         3 . The solar cell of  claim 2 , wherein each of the plurality of first contact lines has a width of about 20 μm to 60 μm, and/or a plane area of each of the plurality of first contact lines is about 2% to 6% of a plane area of the emitter layer. 
     
     
         4 . (canceled) 
     
     
         5 . The solar cell of  claim 3 , wherein the first electrode has a thickness of about 20 μm to 50 μm. 
     
     
         6 . The solar cell of  claim 1 , wherein the first surface and the second surface of the substrate are textured to form a first textured surface and a second textured surface, respectively. 
     
     
         7 . The solar cell of  claim 1 , wherein the first anti-reflection layer includes a silicon nitride layer and a silicon oxide layer or an aluminum oxide layer positioned between the emitter layer and the silicon nitride layer. 
     
     
         8 . The solar cell of  claim 1 , wherein the substrate is formed of an n-type silicon wafer doped with phosphorus (P). 
     
     
         9 . The solar cell of  claim 1 , further comprising:
 a back surface field layer positioned at the second surface of the substrate; and   a second anti-reflection layer positioned on a surface of the back surface field layer on which the second electrode is not positioned.   
     
     
         10 . The solar cell of  claim 8 , wherein the plating layer includes a metal seed layer that directly contacts the emitter layer and contains nickel, and at least one conductive layer that is positioned on the metal seed layer and contains at least one selected from the group consisting of copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au), and a combination thereof, and the second electrode formed of silver (Ag). 
     
     
         11 . The solar cell of  claim 9 , wherein a width of the second electrode is greater than a width of the first electrode. 
     
     
         12 . (canceled) 
     
     
         13 . The solar cell of  claim 9 , wherein the second anti-reflection layer includes a silicon nitride layer, and the second anti-reflection layer includes a plurality of second contact lines exposing a portion of the back surface field layer. 
     
     
         14 . (canceled) 
     
     
         15 . The solar cell of  claim 11 , wherein each of the plurality of second contact lines has a width of about 40 μm to 100 μm, and/or a plane area of each of the plurality of second contact lines is about 5% to 15% of a plane area of the back surface field layer. 
     
     
         16 . (canceled) 
     
     
         17 . The solar cell of  claim 9 , wherein the plating layer includes a metal seed layer that directly contacts the emitter layer and contains nickel, and at least one conductive layer that is positioned on the metal seed layer and contains at least one selected from the group consisting of copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au), and a combination thereof, and the first and second electrodes have the same structure. 
     
     
         18 . (canceled) 
     
     
         19 . A method for manufacturing a solar cell comprising:
 forming an emitter layer at a first surface of a substrate and forming a back surface field layer at a second surface of the substrate;   forming a first anti-reflection layer on a surface of the emitter layer and forming a second anti-reflection layer on a surface of the back surface field layer;   forming a plurality of first contact lines on the first anti-reflection layer;   forming a second electrode on a surface of the second anti-reflection layer; and   forming a first electrode on the plurality of first contact lines,   wherein the first electrode and the second electrode are formed of different materials.   
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . The method of  claim 19 , wherein the forming of the plurality of first contact lines includes:
 etching the first anti-reflection layer using a dry etching process using a laser; and   removing a damaged layer of the emitter layer generated by the laser using a wet etching process.   
     
     
         23 . The method of  claim 19 , wherein the forming of the second electrode includes:
 printing a conductive paste obtained by mixing silver (Ag) with a glass fit on a surface of the second anti-reflection layer; and   drying and firing the conductive paste,   wherein the forming of the first electrode includes:
 forming a metal seed layer directly contacting the emitter layer; and 
 forming at least one conductive layer on the metal seed layer. 
   
     
     
         24 . A method for manufacturing a solar cell comprising:
 forming an emitter layer at a first surface of a substrate and forming a back surface field layer at a second surface of the substrate;   forming a first anti-reflection layer on a surface of the emitter layer and forming a second anti-reflection layer on a surface of the back surface field layer;   forming a plurality of first contact lines on the first anti-reflection layer and forming a plurality of second contact lines on the second anti-reflection layer; and   forming a first electrode on the emitter layer exposed through the plurality of first contact lines and forming a second electrode on the back surface field layer exposed through the plurality of second contact lines,   wherein the first electrode and the second electrode are formed of the same material.   
     
     
         25 . (canceled) 
     
     
         26 . (canceled) 
     
     
         27 . The method of  claim 24 , wherein the forming of the plurality of first and second contact lines includes:
 etching the first anti-reflection layer and the second anti-reflection layer using a dry etching process using a laser; and   removing a damaged layer of the emitter layer and a damaged layer of the back surface field layer, that are generated by the laser, using a wet etching process.   
     
     
         28 . The method of  claim 24 , wherein the forming of the first and second electrodes includes:
 forming a metal seed layer directly contacting the emitter layer or the back surface field layer; and   forming at least one conductive layer on the metal seed layer.   
     
     
         29 . (canceled)