Solar cell and fabricating method thereof

Abstract

A method for fabricating a solar cell includes the steps of providing a substrate, forming a transparent conductive layer on a surface of the substrate, forming a plurality of photoresist patterns on the transparent conductive layer, forming a dielectric layer on the photoresist patterns and the transparent conductive layer, in which a part of a sidewall of the photoresist pattern is exposed from the dielectric layer, removing the photoresist patterns and a part of the dielectric layer covering the photoresist pattern so that a plurality of openings are defined in the remaining part of the dielectric layer, and forming plural electrodes in the openings respectively. A solar cell fabricated by the method is also disclosed.

What is claimed is: 
     
         1 . A fabricating method for solar cells, comprising:
 providing a substrate;   forming a transparent conductive layer on a surface of the substrate;   forming a plurality of photoresist patterns on the transparent conductive layer;   forming a dielectric layer on the photoresist patterns and the transparent conductive layer, in which a part of a sidewall of the photoresist pattern is exposed from the dielectric layer;   removing the photoresist patterns and a part of the dielectric layer covering the photoresist pattern so that a plurality of openings are defined in the remaining part of the dielectric layer; and   forming a plurality of electrodes in the openings respectively.   
     
     
         2 . The fabricating method of  claim 1 , further comprising the step of forming a seed conductive layer on the transparent conductive layer before the photoresist patterns are formed, wherein the electrodes are formed on the seed conductive layer. 
     
     
         3 . The fabricating method of  claim 1 , wherein sidewalls of the electrodes are substantially perpendicular to the transparent conductive layer. 
     
     
         4 . The fabricating method of  claim 1 , further comprising:
 removing the dielectric layer after the electrodes are formed.   
     
     
         5 . The fabricating method of  claim 1 , wherein the electrodes are formed in the openings by an electroplating process in the step of forming the electrodes. 
     
     
         6 . The fabricating method of  claim 1 , wherein the substrate comprises:
 an N-type single crystal silicon layer;   a first heterogeneous interlayer and a second heterogeneous interlayer formed on two opposite surfaces of the N-type single crystal silicon layer;   a P-type amorphous silicon layer formed on the first heterogeneous interlayer; and   an N-type amorphous silicon layer formed on the second heterogeneous interlayer.   
     
     
         7 . The fabricating method of  claim 6 , wherein the transparent conductive layer is formed on the P-type amorphous silicon layer or the N-type amorphous silicon layer. 
     
     
         8 . A solar cell, comprising:
 a substrate;   a transparent conductive layer formed on a surface of the substrate;   a dielectric layer formed on the transparent conductive layer and having a plurality of openings and a plurality of protrusions surrounding the openings; and   a plurality of electrodes respectively formed in the openings, wherein the height of each of the protrusions is gradually and outwardly decreased from the electrodes to the dielectric layer.   
     
     
         9 . The solar cell of  claim 8 , wherein sidewalls of the electrodes are substantially perpendicular to the transparent conductive layer. 
     
     
         10 . The solar cell of  claim 8 , wherein the substrate comprises an N-type single crystal silicon layer;
 a first heterogeneous interlayer and a second heterogeneous interlayer formed on two opposite surfaces of the N-type single crystal silicon layer;   a P-type amorphous silicon layer formed on the first heterogeneous interlayer; and   an N-type amorphous silicon layer formed on the second heterogeneous interlayer.   
     
     
         11 . The solar cell of  claim 10 , wherein the transparent conductive layer is formed on the P-type amorphous silicon layer or the N-type amorphous silicon layer. 
     
     
         12 . The solar cell of  claim 8 , wherein the electrodes are made of copper, and a height of the electrodes is about 5 micrometers (μm). 
     
     
         13 . The solar cell of  claim 8 , further comprising a plurality of seed conductive patterns respectively formed between the electrodes and the substrate. 
     
     
         14 . The solar cell of  claim 13 , wherein the seed conductive patterns are made of copper, and a height of the seed conductive patterns is about 0.1 micrometers(μm).