Patent Publication Number: US-10312448-B2

Title: Process of manufacturing an electron transport material

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Non-Provisional application which claims the benefit of and priority to U.S. Provisional Application Ser. No. 62/235,844 filed Oct. 1, 2015, entitled “Process of Manufacturing an Electron Transport Material,” which is hereby incorporated by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     None. 
     FIELD OF THE INVENTION 
     This invention relates to a method of manufacturing an interfacial material used in organic bulk heterojunction devices. 
     BACKGROUND OF THE INVENTION 
     Solar energy using photovoltaic effect requires active semiconducting materials to convert light into electricity. Currently, solar cells based on silicon are the dominating technology due to their high conversion efficiency. Recently, solar cells based on organic materials showed interesting features, especially on the potential of low cost in materials and processing. Judging from the recent success in organic light emitting diodes based on a reverse effect of photovoltaic effect, organic solar cells are very promising. 
     Polymeric solar cells are promising approach to photovoltaic applications as they are cost-effective, flexible, lightweight and potentially disposable. [6,6]-phenyl-C 60 -butyric acid-2-hydroxyethyl ester has been found to be capable of being used in organic photovoltaics, however it lacks in exhibiting high short-circuit current density and fill factor. There exists a need to produce a polar fullerene derivative yielding high photovoltaic performances by exhibiting higher short-circuit current density and fill factor. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     A process of dissolving 
                         
in a solvent to produce a first mixture. To the first mixture a reagent is added to produce a second mixture. A H—N—R′-R″ is then added to the second mixture to produce a third mixture. The third mixture is then refluxed to produce
 
     
       
         
         
             
             
         
       
     
     Another process is taught of dissolving [6,6]-phenyl-C 60 -butyric acid methyl ester in 1,2-dichlorobenzene, under an oxygen free environment, to produce a first mixture. Dibutyltin(IV) oxide can then be added to the first mixture to produce a second mixture. To the second mixture ethylenediamine can be added to produce a third mixture. The third mixture can then be refluxed to produce a [6,6]-phenyl-C 60 -butyric-N-(2-aminoethyl)acetamide. 
     Another process can be taught of dissolving [6,6]-phenyl-C 60 -butyric acid methyl ester in 1,2-dichlorobenzene, under an oxygen free environment, to produce a first mixture. Dibutyltin(IV) oxide can then be added to the first mixture to produce a second mixture. To the second mixture 1-ethanol-2-amine can be added to produce a third mixture. The third mixture can then be refluxed to produce a [6,6]-phenyl-C 60 -butyric-N-(2-hydroxyethyl)acetamide. 
     An electron transport material is also taught comprising of either [6,6]-phenyl-C 60 -butyric-N-(2-aminoethyl)acetamide, or [6,6]-phenyl-C 60 -butyric-N-(2-hydroxy ethyl)acetamide. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present invention and benefits thereof may be acquired by referring to the follow description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  depicts the process to produce 
       
         
           
           
               
               
           
         
       
         FIG. 2  depicts the [6,6]-phenyl-C 60 -butyric-N-(2-hydroxyethyl)acetamide  1 H NMR spectrum. 
         FIG. 3  depicts the [6,6]-phenyl-C 60 -butyric-N-(2-hydroxyethyl)acetamide  1 H- 1 H correlation spectrum. 
         FIG. 4  depicts the [6,6]-phenyl-C 60 -butyric-N-(2-hydroxyethyl)acetamide  1 H- 13 C heteronuclear single-quantum correlation spectrum overlaid with the  1 H- 13 C heteronuclear multiple-bond correlation spectrum. 
     
    
    
     DETAILED DESCRIPTION 
     Turning now to the detailed description of the preferred arrangement or arrangements of the present invention, it should be understood that the inventive features and concepts may be manifested in other arrangements and that the scope of the invention is not limited to the embodiments described or illustrated. The scope of the invention is intended only to be limited by the scope of the claims that follow. 
     The present embodiment describes a process to produce 
                         
As shown in  FIG. 1 , the process begins by dissolving
 
                         
in a solvent to produce a first mixture, step  101 . To the first mixture a reagent is added to produce a second mixture, step  103 . A H—N—R′—R″ is then added to the second mixture to produce a third mixture, step  105 . The third mixture is then refluxed to produce
 
                         
step  107 .
 
     In one embodiment R can be selected from groups such as H, CH 3 , carbonate, SH, F, Cl, Br, I, CN, OH, Si, NH 2 , and any alkyl chains 
     As described above step  101  begins by dissolving 
                         
in a solvent to produce a first mixture. Any conventionally known solvent capable of dissolving
 
                         
can be used. In one example the solvent used can be any conventionally known organic solvent. Examples of organic solvents can include dichlorobenzene, chlorobenzene, xylene, toluene, chloroform, tetrahydronaphthalene, carbon disulfide, dichloromethane, ethyl acetate, ethanol, hexane, cyclohexane, tetrahydrofuran and isopropanol. Any conventionally known method of dissolving
 
                         
in the solvent can be used. These methods include mixing, stirring and heating and sonicating.
 
     In step  103 , a reagent can be added to the first mixture to produce a second mixture. These reagents used can be any agent able to cleave R from 
                         
The addition of the reagent to the first mixture is ideally done in an oxygen-free environment but not required. In one embodiment the agent is a metal oxide. In another embodiment the reagent is an acid. In another embodiment the reagent is dibutyltin (IV) oxide, hydrochloric acid, sulfuric acid, nitric acid, or acetic acid. In another embodiment a combination of the mentioned reagents is used.
 
     In step  105 , a H—N—R′—R″ can be added to the second mixture to produce a third mixture. In one embodiment R′ is selected from —(CH 2 ) n —, where n is any integer of one or greater. Also R″ is selected from either N, O, S, C, or B. In other embodiment R″ can be alkyl chains or substituted alkyl chains. Examples of substitutions for the substituted alkyl chains include halogens, NH 2 , Br, OH, Si, or S. In one example R′ is an ethyl group of the structure —(CH2CH2)- and R″ can be selected from NH 2  or OH. 
     In step  107 , the third mixture is then refluxed to produce 
                         
Dependent upon the selection of H—N—R′R″
 
                         
could be [6,6]-phenyl-C 60 -butyric-N-(2-aminoethyl)acetamide, or [6,6]-phenyl-C 60 -butyric-N-(2-hydroxyethyl)acetamide.
 
     The molar ratios of the chemical used can be. 
     
       
         
           
               
               
               
             
               
                   
               
               
                   
                 Chemical 
                 Molar Ratio 
               
               
                   
               
             
            
               
                   
                 
                   
                     
                     
                         
                         
                     
                   
                 
                   1 ± 0.9 
               
               
                   
               
               
                   
                 Reagent 
                 200 ± 199 
               
               
                   
                 H—R′—R″ 
                 200 ± 199 
               
               
                   
               
            
           
         
       
     
     The following examples of certain embodiments of the invention are given. Each example is provided by way of explanation of the invention, one of many embodiments of the invention, and the following examples should not be read to limit, or define, the scope of the invention. 
     Example 1 
     [6,6]-Phenyl-C 60 -butyric acid methyl ester (0.25 g, 0.274 mmol) was dissolved in 1,2-dichlorobenzene (12 mL) in a dry schlenk flask under argon. Dibutyltin(IV) oxide (0.068 g, 0.274 mmol) was added in one portion. Ethylenediamine (0.2 mL) was added in one portion and the solution heated to 180° C. for two hours. The brown precipitate was filtered, sonicated in methanol and centrifuged. The solid [6,6]-phenyl-C 60 -butyric-N-(2-aminoethyl)acetamide was sonicated in acetone and centrifuged to yield the product as a brown solid (0.21 g, 84% yield). 
     Example 2 
     [6,6]-Phenyl-C 60 -butyric acid methyl ester (2.0 g, 2.2 mmol) was dissolved in dry 1,2-dichlorobenzene (25 mL) in a dry Schlenk flask under argon. Dibutyltin(IV) oxide (0.548 g, 22 mmol) was added in one portion. Ethanolamine (0.134 g, 2.2 mmol) was added via syringe and the solution was heated to reflux for 18 hours. The solution was cooled and poured directly onto a column packed with toluene. The solvent was gradually changed to a 4:1 toluene/tetrahydrofuran mix and pure [6,6]-phenyl-C 60 -butyric-N-(2-hydroxyethyl)acetamide was isolated as a brown powder (0.12 g, 24% yield). 
     NMR Spectroscopy 
     Nuclear magnetic resonance spectroscopy was performed on a 400 NMR spectrometer, operating at 400.16 MHz for  1 H. 
       FIG. 2  depicts the [6,6]-phenyl-C 60 -butyric-N-(2-hydroxyethyl)acetamide  1 H NMR spectrum. 
       FIG. 3  depicts the [6,6]-phenyl-C 60 -butyric-N-(2-hydroxyethyl)acetamide  1 H- 1 H correlation spectrum. 
       FIG. 4  depicts the [6,6]-phenyl-C 60 -butyric-N-(2-hydroxyethyl)acetamide  1 H- 13 C heteronuclear single-quantum correlation spectrum overlaid with the  1 H- 13 C heteronuclear multiple-bond correlation spectrum. 
     Performance Data 
     Average performance data of different organic photovoltaic devices using different electron transport layers were done. 
     
       
         
           
               
               
               
               
               
             
               
                   
               
               
                   
                 Open-circuit 
                 Short-circuit 
                   
                   
               
               
                   
                 voltage 
                 current 
                 Fill 
                 Power 
               
               
                 Electronic 
                 Voc 
                 density Jsc 
                 Factor 
                 Conversion 
               
               
                 Transport layer 
                 (V) 
                 in mA/cm 2   
                 % 
                 Efficiency % 
               
               
                   
               
             
            
               
                 ZnO 
                 0.785 
                 15.9 
                 65.9 
                 8.24 
               
               
                 ZnO:[6,6]-phenyl- 
                 0.756 
                 16.0 
                 57.6 
                 6.99 
               
               
                 C 60 -butyric-N- 
               
               
                 (2-hydroxyethyl)- 
               
               
                 acetamide 
               
               
                   
               
            
           
         
       
     
     In closing, it should be noted that the discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. At the same time, each and every claim below is hereby incorporated into this detailed description or specification as an additional embodiment of the present invention. 
     Although the systems and processes described herein have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention as defined by the following claims. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described herein. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims while the description, abstract and drawings are not to be used to limit the scope of the invention. The invention is specifically intended to be as broad as the claims below and their equivalents.