Solar cell

Abstract

A solar cell that capable of improving light utilization efficiency is disclosed. The solar cell comprises I-VII compound photovoltaic layer, silicon photovoltaic layer, first electrode and second electrode. The I-VII compound photovoltaic layer comprises first and second type I-VII compound layers. The first and second type I-VII compound layer have first and second type impurities, respectively. The second type I-VII compound layer is disposed under the first type I-VII compound layer. The silicon photovoltaic layer comprises first and second type silicon layers. The first and second type silicon layers have first and second type dopants, respectively. The first type and second type silicon layers are disposed under the second type I-VII compound layer and the first type silicon layer, respectively. The first and second electrodes are formed under the second type silicon layer and on a portion of the first type I-VII compound layer, respectively.

1 . A solar cell comprising:
 a I-VII compound photovoltaic layer including a first type I-VII compound layer and a second type I-VII compound layer, the first type I-VII compound layer having a first type impurities, the second type I-VII compound layer having a second type impurities of which polarity is opposite to a polarity of the first type impurities, and the second type I-VII compound layer being disposed under the first type I-VII compound layer;   a silicon photovoltaic layer including a first type silicon layer and a second type silicon layer, the first type silicon layer having first type dopants, the second type silicon layer having second type dopants of which polarity is opposite to a polarity of the first type dopants, the first type silicon layer being disposed under the second type I-VII compound layer, and the second type silicon layer being disposed under the first type silicon layer;   a first electrode formed under the second type silicon layer; and   a second electrode formed on a portion of the first type I-VII compound layer to expose remaining portion of the first type I-VII compound layer.   
     
     
         2 . The solar cell of  claim 1 , wherein the I-VII compounds include CuCl, CuBr, CuI, AgBr, AgI, CuF, AgF, AgCl, AuF, AuCl, AuBr, AuI, CuFCl, CuBrF, CuFI, CuClBr, CuClI, CuBrI, AgFCl, AgFBr, AgFI, AgClBr, AgClI, AgBrI, AuFCl, AuFBr, AuFI, AuClBr, AuClI, AuBrI, CuF-ClBr, CuFClI, CuFBrI, CuIBrCl, AgFClBr, AgFClI, AgFBrI, AgClBrI, AuFClBr, AuFClI or AuClBrI. 
     
     
         3 . The solar cell of  claim 1 , wherein the first type and the second type are p-type and n-type, or n-type or p-type, respectively. 
     
     
         4 . The solar cell of  claim 1 , further comprising:
 an undoped I-VII compound layer between the first type I-VII compound layer and the second type I-VII compound layer.   
     
     
         5 . The solar cell of  claim 1 , further comprising:
 an undoped silicon layer between the first type silicon layer and the second type silicon layer.