Photovoltaic device and manufacturing method thereof

Abstract

A photovoltaic device capable of improving an output characteristic is provided. The photovoltaic device includes an n-type single-crystal silicon substrate, a p-type amorphous silicon substrate, and a substantially intrinsic i-type amorphous silicon layer disposed between the n-type single-crystal silicon substrate and the p-type amorphous silicon layer. The i-type amorphous silicon layer includes: a first section which is located on the n-type single-crystal silicon substrate side, and which has an oxygen concentration equal to or below 10 20 cm −3 ; and a second section which is located on the p-type amorphous silicon layer side, and which has an oxygen concentration equal to or above 10 20 cm −3 .

1 - 14 . (canceled) 
     
     
         15 . A method of manufacturing a photovoltaic device comprising the steps of:
 preparing a silicon substrate;   forming a first amorphous silicon layer on a first surface of the silicon substrate by introducing a first gas containing silane and carbon dioxide;   forming a second amorphous silicon layer on the first amorphous silicon layer by introducing a second gas containing silane and boron;   forming a third amorphous silicon layer on a second surface of the silicon substrate by introducing a third gas containing silane;   forming a fourth amorphous silicon layer on the third amorphous silicon layer formed on the second surface of the silicon substrate by introducing a second gas containing silane and phosphorous.   
     
     
         16 . The method according to  claim 15 ,
 wherein the first surface of the silicon substrate is treated with hydrogen gas before introducing the first gas.   
     
     
         17 . The method according to  claim 16 ,
 wherein the silicon substrate is treated by heat before treating with hydrogen gas.   
     
     
         18 . The method according to  claim 15 ,
 wherein the third gas does not contain carbon dioxide.   
     
     
         19 . The method according to  claim 16 ,
 wherein the third gas does not contain carbon dioxide.   
     
     
         20 . The method according to  claim 17 ,
 wherein the third gas does not contain carbon dioxide.   
     
     
         21 . The method according to  claim 15 ,
 wherein the first gas is introduced while a flow rate of carbon dioxide is continuously changed.   
     
     
         22 . The method according to  claim 16 ,
 wherein the first gas is introduced while a flow rate of carbon dioxide is continuously changed.   
     
     
         23 . The method according to  claim 17 ,
 wherein the first gas is introduced while a flow rate of carbon dioxide is continuously changed.   
     
     
         24 . The method according to  claim 18 ,
 wherein the first gas is introduced while a flow rate of carbon dioxide is continuously changed.