Method for manufacturing solar cell

Abstract

Disclosed are a relatively high-efficiency solar cell and a method for fabricating the same using a micro-heater array. The solar cell may include first and second micro-heaters intersecting each other or being parallel to each other on a substrate, and a plurality of In x Ga 1-x N p-n junction layers formed using the first and second micro-heaters. The solar cell has improved efficiency because sunlight with various wavelengths may be effectively absorbed by the plurality of In x Ga 1-x N p-n junction layers. Furthermore, relatively large-sized solar cells may be fabricated, because the plurality of In x Ga 1-x N p-n junction layers may be formed on a glass substrate using a micro-heater array.

1 .- 17 . (canceled) 
     
     
         18 . A method for fabricating a solar cell, comprising:
 applying a first voltage to a micro-heater array in the presence of source and doping gases, the micro-heater array having a first heating portion extending in a first direction and a second heating portion extending in a second direction so as to traverse the first heating portion; and   forming a first plurality of In x Ga 1-x N p-n junction layers at a juncture of the first and second heating portions, x being a number from 0 to 1 and each of the first plurality of In x Ga 1-x N p-n junction layers having a different value for x.   
     
     
         19 . The method of  claim 18 , wherein:
 the micro-heater array is provided in a chamber,   the first voltage is applied to heat one of the first or second heating portions of the micro-heater array,   a p-type doping gas is injected into the chamber to grow a p-type In x Ga 1-x N layer on the first heating portion or the second heating portion heated by the first voltage, and   an n-type doping gas is injected into the chamber to grow an n-type In x Ga 1-x N layer on the first heating portion or the second heating portion heated by the first voltage, the p-type and n-type doping gases being injected sequentially for one or more cycles to form the first plurality of In x Ga 1-x N p-n junction layers, the first plurality of In x Ga 1-x N p-n junction layers having alternating p-type and n-type In x Ga 1-x N layers.   
     
     
         20 . The method of  claim 19 , further comprising:
 applying a second voltage to another of the first or second heating portions; and   injecting p-type or n-type doping gases into the chamber to grow a second p-type or n-type In x Ga 1-x N layer on the first heating portion or the second heating portion heated by the second voltage,   wherein the second p-type or n-type In x Ga 1-x N layer contacts the outermost layer of the first plurality of In x Ga 1-x N p-n junction layers, the second p-type or n-type In x Ga 1-x N layer and the outermost layer of the first plurality of In x Ga 1-x N p-n junction layer being In x Ga 1-x N layers of different types.   
     
     
         21 . The method of  claim 19 , further comprising:
 applying a second voltage to another of the first or second heating portions; and   sequentially injecting p-type and n-type doping gases into the chamber for one or more cycles to form a second plurality of In x Ga 1-x N p-n junction layers on the first or second heating portion heated by the second voltage,   wherein the outermost layer of the second plurality of In x Ga 1-x N p-n junction layers contacts the outermost layer of the first plurality of In x Ga 1-x N p-n junction layers, the outermost layers being In x Ga 1-x N layers of different types.   
     
     
         22 . A method for fabricating a solar cell, comprising:
 applying a first voltage to a micro-heater array in the presence of source and doping gases, the micro-heater array having first and second heating portions extending in parallel; and   forming a first plurality of In x Ga 1-x N p-n junction layers on one of the first or second heating portions, x being a number from 0 to 1 and each of the first plurality of In x Ga 1-x N p-n junction layers having a different value for x.   
     
     
         23 . The method of  claim 22 , wherein:
 the micro-heater array is provided in a chamber,   the first voltage is applied to heat one of the first or second heating portions of the micro-heater array,   a p-type doping gas is injected into the chamber to grow a p-type In x Ga 1-x N layer on the first heating portion or the second heating portion heated by the first voltage, and   an n-type doping gas is injected into the chamber to grow an n-type In x Ga 1-x N layer on the first heating portion or the second heating portion heated by the first voltage, the p-type and n-type doping gases being injected sequentially for one or more cycles to form the first plurality of In x Ga 1-x N p-n junction layers, the first plurality of In x Ga 1-x N p-n junction layers having alternating p-type and n-type In x Ga 1-x N layers.   
     
     
         24 . The method of  claim 23 , further comprising:
 applying a second voltage to another of the first or second heating portions; and   injecting p-type or n-type doping gases into the chamber to grow a second p-type or n-type In x Ga 1-x N layer on the first heating portion or the second heating portion heated by the second voltage,   wherein the second p-type or n-type In x Ga 1-x N layer contacts the outermost layer of the first plurality of In x Ga 1-x N p-n junction layers, the second p-type or n-type In x Ga 1-x N layer and the outermost layer of the first plurality of In x Ga 1-x N p-n junction layer being In x Ga 1-x N layers of different types.   
     
     
         25 . The method of  claim 23 , further comprising:
 applying a second voltage to another of the first or second heating portions; and   sequentially injecting p-type and n-type doping gases into the chamber for one or more cycles to form a second plurality of In x Ga 1-x N p-n junction layers on the first or second heating portion heated by the second voltage,   wherein the outermost layer of the second plurality of In x Ga 1-x N p-n junction layers contacts the outermost layer of the first plurality of In x Ga 1-x N p-n junction layers, the outermost layers being In x Ga 1-x N layers of different types.   
     
     
         26 . A method for fabricating a solar cell, comprising:
 applying a first voltage to a micro-heater array in the presence of source and doping gases, the micro-heater array having a first heating portion extending along a first line and a second heating portion extending along a second line, the second line being spaced from the first line; and   forming a first plurality of In x Ga 1-x N p-n junction layers on one of the first and second heating portions, x being a number from 0 to 1 and each of the first plurality of In x Ga 1-x N p-n junction layers having a different value for x.   
     
     
         27 . The method of  claim 26 , wherein the first and second lines are orthogonal and forming the first plurality of In x Ga 1-x N p-n junction layers is at a juncture of the first and second heating portions. 
     
     
         28 . The method of  claim 26 , wherein the first and second lines are parallel.