Dispersant compound and method for preparing the same

Abstract

Disclosed herein are a novel oligomeric compound with improved dispersion performance and a method for preparing the same. The oligomeric compound comprises a tail structure consisting of hydrophilic and hydrophobic blocks and an amine or imidazole head structure. The dye containing the compound can be used to prepare a paste composition for a semiconductor electrode of a solar cell. A semiconductor electrode produced using the paste composition and a solar cell fabricated using the semiconductor electrode exhibit greatly improved power conversion efficiency and superior processability.

1 . A compound represented by Formula 1 below: 
       
         
           
           
               
               
           
         
         wherein R 1  is an amine or imidazole group, 
         X 1 , X 2 , X 3  and X 4  are each independently H or methyl, 
         A is a substituted or unsubstituted C 6 -C 30  arylene group, a substituted or unsubstituted C 6 -C 30  arylalkylene group, or a substituted or unsubstituted C 6 -C 30  cycloalkylene group, 
         B is a substituted or unsubstituted C 1 -C 20  alkyl group, a substituted or unsubstituted C 1 -C 20  alkenyl group, or a substituted or unsubstituted C 1 -C 20  alkynyl group, wherein B has a linear or branched structure, 
         m is an integer from 1 to 20, and 
         n is 0 or 1. 
       
     
     
         2 . The compound according to  claim 1 , wherein the compound is a compound represented by Formula 2 below: 
       
         
           
           
               
               
           
         
         R 2 , R 3 , R 4 , R 5  and R 6  are each independently H or methyl, 
         k is an integer from 5 to 10, 
         l is 0 or 1, and 
         m is an integer from 4 to 10. 
       
     
     
         3 . The compound according to  claim 1 , wherein the compound is a compound represented by Formula 3 below: 
       
         
           
           
               
               
           
         
         R 2 , R 3 , R 4 , R 5  and R 6  are each independently H or methyl, 
         k is an integer from 5 to 10, 
         l is 0 or 1, and 
         m is an integer from 4 to 10. 
       
     
     
         4 . The compound according to  claim 2 , wherein the compound is the compound represented by Formula 4 below: 
       
         
           
           
               
               
           
         
       
     
     
         5 . The compound according to  claim 3 , wherein the compound is the compound represented by Formula 5 below: 
       
         
           
           
               
               
           
         
       
     
     
         6 . A paste composition comprising
 a metal oxide powder,   a dye containing a compound represented by Formula 1 below:   
       
         
           
           
               
               
           
         
         wherein R 1  is an amine or imidazole group, 
         X 1 , X 2 , X 3  and X 4  are each independently H or methyl, 
         A is a substituted or unsubstituted C 6 -C 30  arylene group, a substituted or unsubstituted C 6 -C 30  arylalkylene group, or a substituted or unsubstituted C 6 -C 30  cycloalkylene group, 
         B is a substituted or unsubstituted C 1 -C 20  alkyl group, a substituted or unsubstituted C 1 -C 20  alkenyl group, or a substituted or unsubstituted C 1 -C 20  alkynyl group, wherein B has a linear or branched structure, 
         m is an integer from 1 to 20, and 
         n is 0 or 1; and 
         a binder solution. 
       
     
     
         7 . The paste composition of  claim 6 , comprising
 20 to 50% by weight of the metal oxide powder,   0.1 to 10% by weight of the dye containing the compound of Formula 1 with respect to the weight of the metal oxide powder, and   wherein the balance of the paste composition comprises the binder solution.   
     
     
         8 . The paste composition of  claim 6 , wherein the dyes include ruthenium complexes; xanthene colorants; cyanine colorants; basic dyes; phenosafranine; Capri blue; thiosine; Methylene Blue; porphyrinoid compounds; azo colorants; phthalocyanine compounds; anthraquinone colorants; polycyclic quinone colorants; or a combination comprising two or more of the foregoing dyes. 
     
     
         9 . The paste composition of  claim 8 , wherein the dyes include ruthenium trisbipyridyl, Rhodamine B, Rose Bengal, eosin, erythrosine, quinocyanine cryptocyanine, chlorophyll, zinc porphyrin, magnesium porphyrin, or mixtures thereof. 
     
     
         10 . The paste composition of  claim 6 , wherein the binder composition comprises a solvent and t-butanol in a weight ratio (w/w) of 1:1 to 1:10. 
     
     
         11 . The paste composition of  claim 10 , wherein the solvent comprises water, glycols, glycerols, or an acetate-based solvent. 
     
     
         12 . The paste composition of  claim 6 , wherein the metal oxide comprises at least one metal oxide selected from the group consisting of titanium oxides, niobium oxides, hafnium oxides, indium oxides, tin oxides, zinc oxides, or a combination comprising at least one of the foregoing metal oxides. 
     
     
         13 . The paste composition of  claim 6 , wherein the metal oxide has a nanostructure selected from nanotubes, nanowires, nanobelts, and nanoparticles. 
     
     
         14 . A metal oxide layer prepared by coating the paste composition of  claim 6  on a substrate, and annealing the coated paste composition. 
     
     
         15 . A semiconductor electrode comprising a transparent electrode comprising a substrate and an electrically conductive material coated on a surface of the substrate,
 a metal oxide layer formed on a surface of the transparent electrode having the electrically conducting material, and a dye present in the metal oxide layer wherein the dye contains the compound of  claim 1 .   
     
     
         16 . A solar cell comprising the semiconductor electrode of  claim 15 . 
     
     
         17 . A method for preparing a compound represented by Formula 1 below: 
       
         
           
           
               
               
           
         
         wherein R 1  is an amine or imidazole group, 
         X 1 , X 2 , X 3  and X 4  are each independently H or methyl, 
         A is a substituted or unsubstituted C 6 -C 30  arylene group, a substituted or unsubstituted C 6 -C 30  arylalkylene group, or a substituted or unsubstituted C 6 -C 30  cycloalkylene group, 
         B is a substituted or unsubstituted C 1 -C 20  alkyl group, a substituted or unsubstituted C 1 -C 20  alkenyl group, or a substituted or unsubstituted C 1 -C 20  alkynyl group, wherein B has a linear or branched structure, 
         m is an integer from 1 to 20, and 
         n is 0 or 1, 
         the method comprising the steps of: 
         (1) adding organic solvents to a compound of Formula 6 below: 
       
       
         
           
           
               
               
           
         
         (wherein X 1 , X 2 , X 3 , X 4 , A, B, m and n are as defined in Formula 1), and reacting the compound of Formula 6 with methanesulfonyl chloride for a specified time to prepare a compound represented by Formula 7 below: 
       
       
         
           
           
               
               
           
         
         (wherein X 1 , X 2 , X 3 , X 4 , A, B, m and n are as defined in Formula 1); and 
         (2) adding an amine or imidazole compound to the compound of Formula 7 and allowing the mixture to react for a specified time to prepare the compound of Formula 1. 
       
     
     
         18 . The method according to  claim 17 , wherein the organic solvent is selected from the group consisting of: aliphatic hydrocarbon solvents, including hexane and heptane; aromatic hydrocarbon solvents, including toluene, pyridine, quinoline, anisole, mesitylene, and xylene; ketone-based solvents, including methyl isobutyl ketone, N-methyl-2-pyrrolidone (NMP), 1-methyl-2-pyrrolidinone, cyclohexanone, and acetone; ether-based solvents, including dimethoxy ether, tetrahydrofuran and isopropyl ether; alcohol-based solvents, including ethanol, isopropyl alcohol, butyl alcohol and t-butyl alcohol; amide-based solvents, including dimethylacetamide and dimethylformamide; silicon-based solvents; nitrile-based solvents, including acetonitrile; methanesulfonyl chloride; dichloromethane (CH 2 Cl 2 ); triethylamine; and mixtures thereof. 
     
     
         19 . The method according to  claim 17 , wherein the reaction of step (1) is carried out at room temperature for 2-4 hours. 
     
     
         20 . The method according to  claim 17 , wherein the reaction of step (2) is carried out at 150-200° C. for 2-24 hours.