Solar cell and method of manufacturing the same

Abstract

Disclosed is a solar cell including a semiconductor substrate, and a dopant layer disposed over one surface of the semiconductor substrate and having a crystalline structure different from that of the semiconductor substrate, the dopant layer including a dopant. The dopant layer includes a plurality of semiconductor layers stacked one above another in a thickness direction thereof, and an interface layer interposed therebetween. The interface layer is an oxide layer having a higher concentration of oxygen than that in each of the plurality of semiconductor layers.

1 - 23 . (canceled) 
     
     
         24 . A solar cell comprising:
 a single crystalline semiconductor substrate; and   a first conductive area formed on a first surface of the semiconductor substrate,   wherein the first conductive area comprises a first polycrystalline semiconductor layer, an interface layer, and a second polycrystalline semiconductor layer sequentially stacked in a thickness direction, wherein the interface layer is an oxide layer having a higher oxygen concentration than each of the first polycrystalline semiconductor layer and the second polycrystalline semiconductor layer, and wherein a thickness of the first polycrystalline semiconductor layer is greater than that of the second polycrystalline semiconductor layer.   
     
     
         25 . The solar cell according to  claim 24 , wherein the oxygen concentration of the interface layer is at least 1.5 times the oxygen concentration in each of the first polycrystalline semiconductor layer and the second polycrystalline semiconductor layer. 
     
     
         26 . The solar cell according to  claim 25 , wherein the oxygen concentration of the interface layer is within a range from 2 times to 10 times the oxygen concentration in each of the first polycrystalline semiconductor layer and the second polycrystalline semiconductor layer. 
     
     
         27 . The solar cell according to  claim 24 , wherein the interface layer is thinner than the second polycrystalline semiconductor layer. 
     
     
         28 . The solar cell according to  claim 24 , wherein the interface layer has a thickness of 1 nm or less. 
     
     
         29 . The solar cell according to  claim 24 , further comprising a tunneling layer formed between the single crystalline semiconductor substrate and the first conductive area. 
     
     
         30 . The solar cell according to  claim 29 , wherein a first surface of the tunneling layer is in contact with the first surface of the semiconductor substrate, and a second surface of the tunneling layer is in contact with the first polycrystalline semiconductor layer. 
     
     
         31 . The solar cell according to  claim 29 , wherein the tunneling layer is an oxide layer, and a thickness of the interface layer is equal to or less than a thickness of the tunneling layer. 
     
     
         32 . The solar cell according to  claim 31 , wherein a ratio of the thickness of the tunneling layer to the thickness of the interface layer is within a range from 1:0.1 to 1:0.8. 
     
     
         33 . The solar cell according to  claim 29 , wherein a thickness of the tunneling layer is within a range from 0.5 nm to 1.5 nm 
     
     
         34 . The solar cell according to  claim 29 , wherein the tunneling layer is an oxide layer, and the oxygen concentration of the interface layer is equal to or less than an oxygen concentration of the tunneling layer. 
     
     
         35 . The solar cell according to  claim 24 , wherein the interface layer is in contact with the first polycrystalline semiconductor layer and the second polycrystalline semiconductor layer. 
     
     
         36 . The solar cell according to  claim 24 , further comprising a second conductive area formed on a second surface of the single crystalline semiconductor substrate, wherein the first conductive area has a conductive type opposite to a conductive type of the second conductive area. 
     
     
         37 . The solar cell according to  claim 36 , wherein the second surface is a front surface of the single crystalline semiconductor substrate, and wherein the first surface is a back surface of the single crystalline semiconductor substrate. 
     
     
         38 . The solar cell according to  claim 36 , wherein the conductive type of the first conductive area is the same as a conductive type of the single crystalline semiconductor substrate. 
     
     
         39 . The solar cell according to  claim 38 , wherein a dopant included in the first conductive area has a higher doping concentration than that in the single crystalline semiconductor substrate. 
     
     
         40 . The solar cell according to  claim 36 , further comprising:
 a first passivation layer formed on the first conductive area and having a first opening;   a second passivation layer formed on the second conductive area and having a second opening;   a first electrode connected to the first conductive area through the first opening; and   a plurality of second electrode connected to the second conductive area through the second opening.   
     
     
         41 . The solar cell according to  claim 40 , wherein each of the first electrode and the second electrode comprises a finger electrode and a bus bar electrode. 
     
     
         42 . The solar cell according to  claim 40 , wherein the second passivation layer comprises an anti-reflection film. 
     
     
         43 . The solar cell according to  claim 24 , wherein the single crystalline semiconductor substrate is a single crystalline silicon substrate, the first polycrystalline semiconductor layer is a first polycrystalline silicon layer, the second polycrystalline semiconductor layer is a second polycrystalline silicon layer, and the interface layer is a silicon oxide layer.