Organic photosensitive devices comprising aryl squaraines and methods of making the same

Abstract

There is disclosed squaraine compounds of formula I: wherein each of Y 1 and Y 2 is independently chosen from an optionally substituted amino group and an optionally substituted aryl group. Also described are organic optoelectronic devices comprising a Donor-Acceptor heterojunction that is formed from one or more of the squaraine compounds. A method of making the disclosed device, which may include one or more sublimation step for depositing said squaraine compound, is also disclosed.

1 . A squaraine compound of formula I: 
       
         
           
           
               
               
           
         
         wherein, 
         Y 1  and Y 2  are independently selected from a an optionally substituted amino group or an optionally substituted aryl group. 
       
     
     
         2 . The compound of  claim 1 , wherein Y 1  and Y 2  are independently selected from —NR 3 R 4  and a group of formula II: 
       
         
           
           
               
               
           
         
         wherein X for each occurrence is independently selected from hydrogen and hydroxyl; 
         R 1  and R 2  are independently selected from optionally substituted alkyl, optionally substituted aryl, and optionally substituted heteroaryl, or 
         R 1  and R 2  are taken together with any intervening atoms to form a group selected from optionally substituted heteroaryl and optionally substituted heterocyclyl; and 
         R 3  and R 4  are independently selected from optionally substituted alkyl, optionally substituted aryl, and optionally substituted heteroaryl, or 
         R 3  and R 4  are taken together with any intervening atoms to form a group selected from optionally substituted heteroaryl and optionally substituted heterocyclyl. 
       
     
     
         3 . The compound of  claim 2 , wherein said optionally substituted heteroaryl and said optionally substituted heterocyclyl are independently selected from monocyclic and multicyclic groups. 
     
     
         4 . The compound of  claim 3 , wherein the multicyclic group comprises two or more fused rings. 
     
     
         5 . The compound of  claim 2 , wherein
 at least one of R 3  and R 4  are aryl;   at least one of Y 1  and Y 2  is a group of formula II; and   R 1  and R 2  are taken together with any intervening atoms to form a group selected from optionally substituted heteroaryl and optionally substituted heterocyclyl.   
     
     
         6 . The compound of  claim 2 , wherein the group of formula II is chosen from a group of formula III: 
       
         
           
           
               
               
           
         
         wherein 
         W is selected from S, O, Se, and Te; 
         n is an integer selected from 0 and 1; and 
         R 5  and R 6  are independently selected from optionally substituted amino, cyano, halo, mercapto, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted alkyl, optionally substituted aryl, and optionally substituted heteroaryl, optionally substituted heterocyclyl, and optionally substituted carbocyclyl, or 
         R 5  and R 6  attached to adjacent atoms are taken together with any intervening atoms to form a group selected from optionally substituted aryl, optionally substituted heteroaryl, optionally substituted carbocyclyl, and optionally substituted heterocyclyl. 
       
     
     
         7 . The compound of  claim 2 , wherein
 Y 1  is —NR 3 R 4 ; and   Y 2  is   
       
         
           
           
               
               
           
         
       
       and at least one X is hydroxyl. 
     
     
         8 . The compound of  claim 1 , wherein
 Y 1  is —NR 3 R 4 ;   Y 2  is optionally substituted aryl; and   R 3  and R 4  are independently selected from optionally substituted alkyl, optionally substituted aryl, and optionally substituted heteroaryl, or   R 3  and R 4  are taken together with any intervening atoms to form a group selected from optionally substituted heteroaryl and optionally substituted heterocyclyl.   
     
     
         9 . The compound of  claim 1 , wherein
 Y 1  is an optionally substituted aryl;   Y 2  is   
       
         
           
           
               
               
           
         
         X for each occurrence is independently selected from hydrogen and hydroxyl; and 
       
       R 1  and R 2  are independently selected from optionally substituted alkyl, optionally substituted aryl, and optionally substituted heteroaryl, or
 R 1  and R 2  are taken together with any intervening atoms to form a group selected from optionally substituted heteroaryl and optionally substituted heterocyclyl. 
 
     
     
         10 . The compound of  claim 1 , wherein said compound is amorphous. 
     
     
         11 . The compound of  claim 1 , wherein said compound is asymmetric. 
     
     
         12 . The compound of  claim 1 , wherein said compound of formula I is selected from:
 2,4-bis[4-N-carbazolo-2,6-dihydroxyphenyl] squaraine (CBZSQ);   2,4-bis[4-N-phenothiazino-2,6-dihydroxyphenyl] squaraine (PTSQ);   2,4-bis[4-(N,N-diphenylamino)-2,6-dihydroxyphenyl] squaraine (DPSQ);   2,4-bis[4-(N-Phenyl-1-naphthylamino)-2,6-dihydroxyphenyl] squaraine (1NPSQ);   2,4-bis[4-(N-Phenyl-2-naphthylamino)-2,6-dihydroxyphenyl] squaraine (2NPSQ);   {2-[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl]-4-diphenylamino} squaraine (USSQ);   {2-[4-(N,N-diphenylamino)-2,6-dihydroxyphenyl]-4-diphenylamino} squaraine (DPUSQ); and   diphenylamino-squarate (YSQ).   
     
     
         13 . An organic photosensitive optoelectronic device comprising at least one compound of  claim 1 , wherein said device comprises at least one donor-acceptor heterojunction selected from a mixed or bulk heterojunction. 
     
     
         14 . The organic photosensitive optoelectronic device of  claim 13 , wherein said device is a solar cell or photodetector. 
     
     
         15 . The organic photosensitive optoelectronic device of  claim 14 , wherein the device is a solar cell and the donor-acceptor heterojunction is formed at an interface of a donor material comprising the at least one compound of  claim 1  and an acceptor material comprising at least one compound selected from perylenes, phthalocyanines, porphyrins, napthalenes, fullerenes, and nanotubules. 
     
     
         16 . The organic photosensitive optoelectronic device of  claim 13 , wherein the acceptor material comprises at least one compound selected from C 60 , C 70 , C 84 , 3,4,9,10-perylenetracarboxylic dianhydride (PTCDA), 3,4,9,10-perylenetracarboxylic diimide (PTCDI), 3,4,9,10-perylenetetracarboxylic-bis-benzimidazole (PTCBI), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA), copper pthalocyanine (CuPc), and copper-hexadecafluoro-phthalocyanine (F 16 —CuPc). 
     
     
         17 . The organic photosensitive optoelectronic device of  claim 13 , wherein said donor-acceptor heterojunction comprises at least two different squaraines to provide more efficient light harvesting at wavelengths ranging from 500 to 850 nm, when compared to a donor-acceptor heterojunction comprising, at most, one squaraine. 
     
     
         18 . A method of preparing an organic photosensitive optoelectronic device, said method comprising:
 depositing over a substantially transparent material at least one donor material comprising at least one compound of formula I:   
       
         
           
           
               
               
           
         
       
       wherein:
 Y 1  and Y 2  are independently selected from an optionally substituted amino group or optionally substituted aryl group, 
 
       wherein said method forms at least one donor-acceptor heterojunction at the interface of said donor material and an acceptor material. 
     
     
         19 . The method of  claim 18 , wherein Y 1  and Y 2  are independently selected from —NR 3 R 4  and a group of formula II: 
       
         
           
           
               
               
           
         
         wherein 
         X for each occurrence is independently selected from hydrogen and hydroxyl; 
         R 1  and R 2  are independently selected from optionally substituted alkyl, optionally substituted aryl, and optionally substituted heteroaryl, 
         or R 1  and R 2  are taken together with any intervening atoms to form a group selected from optionally substituted heteroaryl and optionally substituted heterocyclyl; and 
         R 3  and R 4  are independently selected from optionally substituted alkyl, optionally substituted aryl, and optionally substituted heteroaryl, or 
         R 3  and R 4  are taken together with any intervening atoms to form a group selected from optionally substituted heteroaryl and optionally substituted heterocyclyl. 
       
     
     
         20 . The method of  claim 18 , wherein the acceptor material comprises at least one compound selected from C 60 , C 70 , C 84 , 3,4,9,10-perylenetracarboxylic dianhydride (PTCDA), 3,4,9,10-perylenetracarboxylic diimide (PTCDI), 3,4,9,10-perylenetetracarboxylic-bis-benzimidazole (PTCBI), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA), copper pthalocyanine (CuPc), and copper-hexadecafluoro-phthalocyanine (F 16 —CuPc). 
     
     
         21 . The method of  claim 18 , wherein the substrate comprises at least one material selected from indium tin oxide (ITO), tin oxide (TO), gallium indium tin oxide (GITO), zinc oxide (ZO), and zinc indium tin oxide (ZITO), glass polymers, and transparent conductive polymers comprising polyaniline (PANI). 
     
     
         22 . The method of  claim 18 , wherein said depositing comprises one or more processes selected from vacuum deposition and solution processing. 
     
     
         23 . The method of  claim 22 , wherein said solution processing comprises one or more techniques selected from spin coating, spray coating, dip coating, or doctor's blading. 
     
     
         24 . The method of  claim 22 , wherein the at least one compound of formula I is sublimed during vacuum deposition one or more times. 
     
     
         25 . The method of  claim 18 , wherein the donor-acceptor heterojunction is formed by depositing the acceptor material over the donor material. 
     
     
         26 . The method of  claim 25 , further comprising depositing at least one electron or exciton blocking material over the donor-acceptor heterojunction. 
     
     
         27 . The method of  claim 26 , wherein said electron or exciton blocking material is chosen from bathocuproine (BCP), bathophenanthroline (BPhen), 3,4,9,10-perylenetetracarboxylicbis-benzimidazole (PTCBI), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi), tris(acetylacetonato) ruthenium(III) (RuAcaca 3 ), and aluminum(III)phenolate (Alq 2  OPH). 
     
     
         28 . The method of  claim 18 , further comprising depositing at least one metal contact over the donor-acceptor heterojunction. 
     
     
         29 . The method of  claim 28 , wherein the at least one metal contact comprises a metal substitute, a non-metallic material or a metallic material chosen from Ag, Au, and Al. 
     
     
         30 . The method of  claim 18 , further comprising depositing at least one second compound of formula Ito form said donor-acceptor heterojunction. 
     
     
         31 . The method of  claim 18 , wherein the at least one compound of formula I is selected from:
 2,4-bis[4-N-carbazolo-2,6-dihydroxyphenyl] squaraine (CBZSQ);   2,4-bis[4-N-phenothiazino-2,6-dihydroxyphenyl] squaraine (PTSQ);   2,4-bis[4-(N,N-diphenylamino)-2,6-dihydroxyphenyl] squaraine (DPSQ);   2,4-bis[4-(N-Phenyl-1-naphthylamino)-2,6-dihydroxyphenyl] squaraine (1NPSQ);   2,4-bis[4-(N-Phenyl-2-naphthylamino)-2,6-dihydroxyphenyl] squaraine (2NPSQ);   {2-[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl]-4-diphenylamino} squaraine (USSQ);   {2-[4-(N,N-diphenylamino)-2,6-dihydroxyphenyl]-4-diphenylamino} squaraine (DPUSQ); and   diphenylamino-squarate (YSQ).   
     
     
         32 . The method of  claim 18 , wherein said compound is asymmetric.