Carrier-selective contact junction silicon solar cell and manufacturing method therefor

Abstract

In a carrier-selective contact junction silicon solar cell according to the present invention, a copper iodine thin film as a hole-selective contact layer is formed through low-temperature annealing so that excellent p-type semiconductor properties are maintained, and electrical conductivity and passivation properties become excellent, thereby improving photoelectric conversion efficiency.

1 . A carrier-selective contact junction silicon solar cell comprising:
 a conductive silicon substrate;   a first passivation layer and a second passivation layer positioned on a top surface and a bottom surface of the conductive silicon substrate, respectively;   a hole-selective contact layer formed on a top surface of the first passivation layer;   an upper transparent electrode formed on a top surface of the hole-selective contact layer;   an upper metal electrode formed on an upper portion of the upper transparent electrode;   an electron-selective contact layer formed on a bottom surface of the second passivation layer; and   a lower metal electrode formed on a bottom surface of the electron-selective contact layer,   wherein, in order to selectively move a hole, the hole-selective contact layer is a single-film copper iodide thin film formed by low-temperature annealing a sandwich-structured multilayer film having copper iodide thin films layered on a top surface and a bottom surface of an iodine thin film.   
     
     
         2 . The carrier-selective contact junction silicon solar cell of  claim 1 , wherein each of the copper iodide thin films of the sandwich-structured multilayer film is formed to have a thickness of 5 to 15 nm. 
     
     
         3 . The carrier-selective contact junction silicon solar cell of  claim 1 , wherein the iodine thin film of the sandwich-structured multilayer film is formed to have a thickness of 1 to 10 nm. 
     
     
         4 . The carrier-selective contact junction silicon solar cell of  claim 1 , wherein the single-film copper iodide thin film is formed to have a thickness of 20 nm. 
     
     
         5 . The carrier-selective contact junction silicon solar cell of  claim 1 , wherein the single-film copper iodide thin film has a composition ratio of Cu:I=1:1. 
     
     
         6 . The carrier-selective contact junction silicon solar cell of  claim 1 , wherein a process atmosphere temperature of the low-temperature annealing ranges from 100 to 200° C. 
     
     
         7 . The carrier-selective contact junction silicon solar cell of  claim 1 , wherein each of the first and second passivation layers includes an intrinsic amorphous silicon thin film (a-Si:H) in order to suppress electron-hole recombination. 
     
     
         8 . The carrier-selective contact junction silicon solar cell of  claim 1 , wherein
 the hole-selective contact layer is formed of a material having a work function (Φ>5.0 eV) higher than a work function of the conductive silicon substrate, and   the electron-selective contact layer is formed of a material having a work function (Φ<3.8 eV) lower than the work function of the conductive silicon substrate.   
     
     
         9 . A method of manufacturing a carrier-selective contact junction silicon solar cell, the method comprising:
 a conductive silicon substrate preparation operation of preparing a conductive silicon substrate including conductive impurities;   a passivation layer forming operation of forming a first passivation layer and a second passivation layer on a top surface and a bottom surface of the conductive silicon substrate, respectively;   an electron-selective contact layer forming operation of forming an electron-selective contact layer on a bottom surface of the second passivation layer;   a hole-selective contact layer forming operation of forming a hole-selective contact layer on a top surface of the first passivation layer;   an upper transparent electrode forming operation of forming an upper transparent electrode on a top surface of the hole-selective contact layer;   an upper metal electrode forming operation of forming an upper metal electrode on an upper portion of the upper transparent electrode; and   a lower metal electrode forming operation of forming a lower metal electrode on a bottom surface of the electron-selective contact layer,   wherein in the hole-selective contact layer forming operation, in order to selectively move a hole, a sandwich-structured multilayer film is formed by depositing a copper iodide thin film on a top surface and a bottom surface of an iodine thin film, and a single-film copper iodide thin film is formed by low-temperature annealing the sandwich-structured multilayer film.   
     
     
         10 . The method of  claim 9 , wherein in the hole-selective contact layer forming operation, the copper iodide thin film having p-type semiconductor properties is formed. 
     
     
         11 . The method of  claim 9 , wherein in the hole-selective contact layer forming operation, a process atmosphere temperature of the low-temperature annealing ranges from 100 to 200° C. 
     
     
         12 . The method of  claim 9 , wherein in the hole-selective contact layer forming operation, the single-film copper iodide thin film has a composition ratio of Cu:I=1:1.