Solar cell upper electrode and manufacturing method therefor

Abstract

Provided in one embodiment of the present invention is a solar cell upper electrode which is positioned on a photoactive layer and which includes a conductive polymer layer, wherein ionic liquid comes in contact with the surface of the conductive polymer layer so as to the post-treated, and, due to the post-treatment, an ion-exchange reaction occurs only in the upper area of the conductive upper electrode according to an embodiment of the present invention is not gelated so as to improve electrode performance, and does not oxidize a photoactive layer positioned under the electrode so as to be usable as an upper electrode, and thus can improve the performance of a solar cell to which the electrode is applied.

1 . An upper electrode for a solar cell, which is located on a photoactive layer and comprises a conductive polymer layer,
 wherein an ionic liquid is in contact with a surface of the conductive polymer layer to be post-treated, and an ion exchange reaction occurs only in an upper area of the conductive polymer layer by the post-treatment, so that an ion pair generated by the ion exchange reaction does not penetrate into the photoactive layer.   
     
     
         2 . The upper electrode for a solar cell according to  claim 1 , wherein the photoactive layer includes a polythiophene-based polymer, a polyfluorene-based polymer, a polyaniline-based polymer, a polycarbazole-based polymer, a polyvinylcarbazole-based polymer, a polyphenylene-based polymer, a polyphenylvinylene-based polymer, a polysilane-based polymer, a polyisothianaphthanene-based polymer, a polythiazole-based polymer, a polybenzothiazole-based polymer, a polythiopheneoxide-based polymer, or a copolymer thereof. 
     
     
         3 . The upper electrode for a solar cell according to  claim 1 , wherein a conductive polymer of the conductive polymer layer is PEDOT:PSS. 
     
     
         4 . The upper electrode for a solar cell according to  claim 1 , wherein the ionic liquid contains 1-ethyl-3-methylimidazolium tetracyanoborate([EMIM +  TCB − ]) 
     
     
         5 . The upper electrode for a solar cell according to  claim 1 , wherein the upper area of the conductive polymer layer has higher electrical conductivity than that of a lower area of the conductive polymer layer. 
     
     
         6 . A solar cell comprising the upper electrode according to  claim 1 . 
     
     
         7 . A method for manufacturing an upper electrode for a solar cell, comprising the steps of:
 forming a conductive polymer layer with a solution containing a conductive polymer on a photoactive layer;   performing post-treatment with an ionic liquid on the conductive polymer layer; and   rinsing the post-treated conductive polymer layer.   
     
     
         8 . The method for manufacturing an upper electrode for a solar cell according to  claim 7 , wherein the photoactive layer includes a polythiophene-based polymer, a polyfluorene-based polymer, a polyaniline-based polymer, a polycarbazole-based polymer, a polyvinylcarbazole-based polymer, a polyphenylene-based polymer, a polyphenylvinylene-based polymer, a polysilane-based polymer, a polyisothianaphthanene-based polymer, a polythiazole-based polymer, a polybenzothiazole-based polymer, a polythiopheneoxide-based polymer, or a copolymer thereof. 
     
     
         9 . The method for manufacturing an upper electrode for a solar cell according to  claim 7 , wherein the conductive polymer is PEDOT:PSS. 
     
     
         10 . The method for manufacturing an upper electrode for a solar cell according to  claim 7 , wherein the ionic liquid contains 1-ethyl-3-methylimidazolium tetracyanoborate([EMIM +  TCB − ]). 
     
     
         11 . The method for manufacturing an upper electrode for a solar cell according to  claim 7 , wherein the step of performing post-treatment is performed by performing a printing process. 
     
     
         12 . The method for manufacturing an upper electrode for a solar cell according to  claim 7 , wherein in the step of performing post-treatment, the ionic liquid is in contact with a surface of the conductive polymer layer so that an ion exchange reaction occurs only in an upper area of the conductive polymer layer. 
     
     
         13 . The method for manufacturing an upper electrode for a solar cell according to  claim 7 , further comprising the step of drying the conductive polymer layer between the step of forming the conductive polymer layer and the step of performing post-treatment.