Solar cell

Abstract

A method for manufacturing a solar cell, includes providing a silicon substrate, forming an oxide layer on a first surface of the silicon substrate, forming a doped polycrystalline silicon layer on the oxide layer, forming a passivation layer on the doped polycrystalline silicon layer, printing a metal paste on the passivation layer, and forming a metal contact connected to the doped polycrystalline silicon layer by firing the metal paste to penetrate the passivation layer.

1 - 20 . (canceled) 
     
     
         21 . A solar cell comprising:
 a silicon substrate having a front doped region formed inside of a front surface of the silicon substrate;   a first tunneling layer formed on the front doped region; and   a first conductive type area formed on the first tunneling layer,   wherein the first tunneling layer has a thickness of 0.5 nm to 5 nm.   
     
     
         22 . The solar cell according to  claim 21 , wherein the first tunneling layer is formed of one of nitride, oxide and oxide nitride. 
     
     
         23 . The solar cell according to  claim 21 , further comprising a first passivation film formed on the first conductive type area. 
     
     
         24 . The solar cell according to  claim 23 , wherein the first passivation film comprises at least one of aluminum oxide, zirconium oxide, or hafnium oxide having a negative charge. 
     
     
         25 . The solar cell according to  claim 23 , wherein the first passivation film comprises at least one of silicon oxide or silicon nitride having a positive charge. 
     
     
         26 . The solar cell according to  claim 23 , further comprising a first anti-reflective film formed on the first passivation film. 
     
     
         27 . The solar cell according to  claim 21 , wherein the silicon substrate is a monocrystalline silicon substrate, and the first conductive type area is formed of one of a polycrystalline silicon, an amorphous silicon or a microcrystalline silicon. 
     
     
         28 . The solar cell according to  claim 21 , wherein the silicon substrate further has a base area, the base area is doped with a first conductive type dopant, the first conductive type area and the front doped region are both doped with a second conductive type dopant, and the front doped region forms a p-n junction along with base area. 
     
     
         29 . The solar cell according to  claim 28 , wherein the base area has a lower doping concentration than the front doped region. 
     
     
         30 . The solar cell according to  claim 21 , wherein a dopant in the first conductive type area and a dopant the front doped region have a same conductive type, and a doping concentration of the first conductive type area is higher than a doping concentration of the front doped region. 
     
     
         31 . The solar cell according to  claim 30 , wherein a ratio of the doping concentration of the first conductive type area to the doping concentration of the front doped region is 5 to 10. 
     
     
         32 . The solar cell according to  claim 30 , wherein the doping concentration of the first conductive type area is 5x10 19 /cm 3  to 5×10 20 /cm 3 , and the doping concentration of the front doped region is 5x10 18 /cm 3  to 5×10 19 /cm 3 . 
     
     
         33 . The solar cell according to  claim 30 , wherein a ratio of a thickness of the first conductive type area to a thickness of the front doped region is 10 to 50. 
     
     
         34 . The solar cell according to  claim 30 , wherein a thickness of the front doped region is 5 nm to 100 nm, and a thickness of the first conductive type area is 50 nm to 500 nm. 
     
     
         35 . The solar cell according to  claim 21 , further comprising a first electrode electrically connected to the first conductive type area. 
     
     
         36 . The solar cell according to  claim 35 , wherein the first tunneling layer is formed only on a portion of the front doped region below the first electrode. 
     
     
         37 . The solar cell according to  claim 35 , wherein the front doped region comprises a first region in contact with the first electrode and a second region not in contact with the first electrode, and wherein the first region has a higher dopant concentration than the second region. 
     
     
         38 . The solar cell according to  claim 35 , further comprising a first passivation film formed on the first conductive type area, wherein the first electrode contacts the first conductive type area through an opening formed in the first passivation film. 
     
     
         39 . The solar cell according to  claim 21 , further comprising: a second tunneling layer, a second conductive type area and a second electrode, wherein the second tunneling layer is interposed between a back surface of the silicon substrate and the second conductive type area, and the second electrode is electrically connected to the second conductive type area. 
     
     
         40 . The solar cell according to  claim 39 , wherein the silicon substrate further comprises a base area and a back doped region formed inside of the back surface of the silicon substrate, the base area and the back doped region are doped with a first conductive type dopant, and the first conductive type area and the front doped region are both doped with a second conductive type dopant.