Visibly transparent photoactive compounds for near-infrared-absorbing photovoltaic devices

Abstract

Visibly transparent photovoltaic devices are disclosed, such as those are transparent to visible light but absorb near-infrared light and/or ultraviolet light. The photovoltaic devices make use of transparent electrodes and near-infrared absorbing visibly transparent photoactive compounds, optical materials, and/or buffer materials.

What is claimed is: 
     
         1 . A photoactive compound having a formula according to: 
       
         
           
           
               
               
           
         
         wherein Z is H or a group having a formula: 
       
       
         
           
           
               
               
           
         
         wherein each Y is independently selected from the group consisting of H, F, Cl, Br, alkoxy, alkyl, and aryl, wherein each X is independently selected from the group consisting of C═C(CN) 2 , O, S, C═O, and SO 2 , and wherein “pi system” is a moiety selected from the group consisting of: 
       
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein R is H, F, Cl, CN, OCH 3 , CH 3 , C(CH 3 ) 3 , an alkyl group, an aromatic group, a heteroaromatic group, an alkylaryl group, a thiazolyl group, a phenyl group, a pyridinyl group, an imidazolyl group, a pyrrolyl group, a thiophenyl group, a naphthyl group, a pyrenyl group, an indolyl group, a benzothiophenyl group, a benzimidazolyl group, a benzothiazolyl group, or where R and R form a fused or unfused aromatic group or a fused or unfused heteroaromatic group, wherein R′ is H, F, Cl, CN, OCH 3 , CH 3 , C(CH 3 ) 3 , a C 1 -C 5  alkyl group, an aryl group, an alkylaryl group, a thiazolyl group, a phenyl group, a pyridinyl group, an imidazolyl group, a pyrrolyl group, a thiophenyl group, a naphthyl group, a pyrenyl group, an indolyl group, a benzothiophenyl group, a benzimidazolyl group, a benzothiazolyl group, or where R′ and R′ form a fused or unfused aromatic group or a fused or unfused heteroaromatic group. 
       
     
     
         2 . The photoactive compound of  claim 1 , exhibiting a first maximum near-infrared absorption strength and a first maximum visible absorption strength, and wherein the first maximum near-infrared absorption strength is greater than the first maximum visible absorption strength. 
     
     
         3 . The photoactive compound of  claim 1 , having a molecular weight of from 200 amu to 1036 amu or from 200 amu to 1000 amu. 
     
     
         4 . The photoactive compound of  claim 1 , wherein X is C═O. 
     
     
         5 . The photoactive compound of  claim 4 , having a formula selected from the group consisting of: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         6 . The photoactive compound of  claim 1 , wherein X is SO 2 . 
     
     
         7 . The photoactive compound of  claim 6 , having a formula selected from the group consisting of: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         8 . The photoactive compound of  claim 1 , wherein X is C═C(CN) 2 . 
     
     
         9 . The photoactive compound of  claim 1 , wherein X is O. 
     
     
         10 . The photoactive compound of  claim 1 , wherein X is S. 
     
     
         11 . A method comprising:
 reacting   
       
         
           
           
               
               
           
         
       
       to generate a photoactive compound, wherein Z′ is —H or —CHO, wherein each Y is independently selected from the group consisting of H, F, Cl, Br, alkoxy, alkyl, and aryl, wherein each X is independently selected from the group consisting of C═C(CN) 2 , O, S, C═O, and SO 2 , and wherein “pi system” is a moiety selected from the group consisting of: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein R is H, F, Cl, CN, OCH 3 , CH 3 , C(CH 3 ) 3 , an alkyl group, an aromatic group, a heteroaromatic group, an alkylaryl group, a thiazolyl group, a phenyl group, a pyridinyl group, an imidazolyl group, a pyrrolyl group, a thiophenyl group, a naphthyl group, a pyrenyl group, an indolyl group, a benzothiophenyl group, a benzimidazolyl group, a benzothiazolyl group, or where R and R form a fused or unfused aromatic group or a fused or unfused heteroaromatic group, wherein R′ is H, F, Cl, CN, OCH 3 , CH 3 , C(CH 3 ) 3 , a C 1 -C 5  alkyl group, an aryl group, an alkylaryl group, a thiazolyl group, a phenyl group, a pyridinyl group, an imidazolyl group, a pyrrolyl group, a thiophenyl group, a naphthyl group, a pyrenyl group, an indolyl group, a benzothiophenyl group, a benzimidazolyl group, a benzothiazolyl group, or where R′ and R′ form a fused or unfused aromatic group or a fused or unfused heteroaromatic group. 
     
     
         12 . The method  claim 11 , wherein the photoactive compound has a formula of: 
       
         
           
           
               
               
           
         
         wherein Z is H or a group having a formula: 
       
       
         
           
           
               
               
           
         
       
     
     
         13 . The method  claim 11 , wherein the photoactive compound exhibits a first maximum near-infrared absorption strength and a first maximum visible absorption strength, and wherein the first maximum near-infrared absorption strength is greater than the first maximum visible ab sorption strength. 
     
     
         14 . The method  claim 11 , wherein the photoactive compound has a molecular weight between 200 amu and 1036 amu. 
     
     
         15 . The method  claim 11 , wherein the photoactive compound has a molecular weight between 200 amu and 1000 amu. 
     
     
         16 . The method  claim 11 , wherein the reacting occurs in the presence of acetic anhydride. 
     
     
         17 . The method  claim 11 , wherein the reacting occurs at a temperature of 90° C. 
     
     
         18 . The method  claim 11 , further comprising purifying the photoactive compound using an evaporation or sublimation-based purification method. 
     
     
         19 . The method  claim 11 , further comprising depositing the photoactive compound onto a surface using a vacuum deposition technique or a thermal evaporation technique. 
     
     
         20 . The method  claim 11 , wherein X is C═O.