Charge transport compositions and electronic devices made with such compositions

Abstract

The present invention is directed to a photoactive device comprising an anode, a cathode, and a photoactive layer, which device further comprises an electron transport and/or anti-quenching layer which minimizes both electron transfer quenching and energy transfer quenching of the photoactive layer.

1 . A photoactive electronic device comprising:
 (a) an anode;   (b) a cathode, said cathode having a work function energy level E 3 ;   (c) a photoactive layer positioned between said anode and said cathode, said photoactive layer comprising a cyclometalated complex of a transition metal, said cyclometalated complex having a LUMO energy level E 2  and a HOMO energy level E 4 ; and   (d) an electron transport and/or anti-quenching layer positioned between said cathode and said photoactive layer, said electron transport and/or anti-quenching layer having a LUMO energy level E 1  and a HOMO energy level E 5 ,   
       with the proviso that:
 (1) E 1 −E 3 <1V, 
 (2) E 1 −E 2 >−1V, and 
 (4) E 4 −E 5 >−1V. 
 
     
     
         2 . The device of  claim 1  wherein E 1 −E 2 >0. 
     
     
         3 . The device of  claim 1  wherein E 4 −E 5 >0. 
     
     
         4 . The device of  claim 1  wherein said electron transport and/or anti-quenching layer has an electron mobility of at least 10 −7  cm 2 /(V·sec). 
     
     
         5 . The device of  claim 1  wherein the electron transport and/or anti-quenching layer comprises a quinoxaline derivative. 
     
     
         6 . The device of  claim 5  wherein the quinoxaline derivative has Formula VI, wherein: 
       
         
           
           
               
               
           
         
         R 4  and R 5  are the same or different at each occurrence and are selected from H, F, Cl, Br, alkyl, heteroalkyl, alkenyl, alkynyl, aryl, heteroaryl, alkylenearyl, alkenylaryl, alkynylaryl, alkyleneheteroaryl, alkenylheteroaryl, alkynylheteroaryl, C n H a F b , OC n H a F b , C 6 H c F d , and OC 6 H c F d , or both of R 5  together may constitute an arylene or heteroarylene group; 
         R 3  is the same or different at each occurrence and is selected from a single bond and a group selected from alkylene, heteroalkylene, arylene, heteroarylene, arylenealkylene, and heteroarylenealkylene; 
         Q is selected from a single bond and a multivalent group; 
         a, b, c, and d are 0 or an integer such that a+b=2n+1, and c+d=5; 
         m is an integer equal to at least 2; 
         n is an integer; and 
         p is 0 or 1. 
       
     
     
         7 . The device of  claim 6 , wherein:
 m is an integer from 2 through 10;   n is an integer from 1 through 12; and   p is 0.   
     
     
         8 . The device of  claim 5  wherein the quinoxaline derivative is selected from Formulae VI(b) through VI(g) and VI(i) through VI(k) in  FIG. 11 . 
     
     
         9 . The device of  claim 5  wherein the quinoxaline derivative is selected from Formulae VI(a), VI(h), VI(l), and VI(m) in  FIG. 11 . 
     
     
         10 . The device of  claim 5 , wherein the quinoxaline derivative has Formula VI(m) shown in  FIG. 11 . 
     
     
         11 . The device of  claim 5 , wherein the quinoxaline derivative has FormulaVII, wherein: 
       
         
           
           
               
               
           
         
         R 4  and R 5  are the same or different at each occurrence and are selected from H, F, Cl, Br, alkyl, heteroalkyl, alkenyl, alkynyl, aryl, heteroaryl, alkylenearyl, alkenylaryl, alkynylaryl, alkyleneheteroaryl, alkenylheteroaryl, alkynylheteroaryl, C n H a F b , OC n H a F b , C 6 H c F d , and OC 6 H c F d , or both of R 5  together may constitute an arylene or heteroarylene group; 
         R 3  is the same or different at each occurrence and is selected from a single bond and a group selected from alkylene, heteroalkylene, arylene, heteroarylene, arylenealkylene, and heteroarylenealkylene; 
         Q is selected from a single bond and a multivalent group; 
         a, b, c, and d are 0 or an integer such that a+b=2n+1, and c+d=5; 
         m is an integer equal to at least 2; 
         n is an integer; and 
         p is 0 or 1. 
       
     
     
         12 . The device of  claim 5 , wherein the device is a light-emitting diode, a light-emitting electrochemical cell, or a photodetector.