Transparent, Thermally Stable Light-Emitting Component Having Organic Layers

Abstract

The presently described subject matter relates to transparent and thermally stable light-emitting components having organic layers, and in particular to a transparent organic light-emitting diode having a charge carrier transport layer which is electrically doped with an organic dopant.

1 . A transparent, thermally stable light-emitting component having organic layers, comprising:
 a transparent substrate;   a transparent anode;   a hole transport layer adjacent to the anode;   at least one light-emitting layer;   a charge-carrier transport layer for electrons; and   a transparent cathode,   wherein the transparency in the visible spectral region is at least 75%,   wherein the hole transport layer is p-doped with an acceptor organic material and the electron transport layer is n-doped with a donor organic material, and the molecular masses of the dopants are each greater than 200 g/mole, and   wherein the transparent, thermally stable light-emitting component having organic layers is an organic light-emitting diode.   
     
     
         2 . A light-emitting component according to  claim 1 , further comprising:
 at least one of a hole-side blocking layer located between the doped hole transport layer and the light-emitting layer or an electron-side blocking layer located between the doped electron transport layer and the light-emitting layer.   
     
     
         3 . A light-emitting component according to  claim 1 , further comprising:
 a electrode layer located between the anode and the hole transport layer and a electrode layer located between the charge-carrier transport layer and the cathode.   
     
     
         4 . A light-emitting component according to  claim 1 , wherein the doping concentration of the organic dopants is such that an ohmic injection takes place from the anode into the charge-carrier transport layer or from the cathode into the hole transport layer. 
     
     
         5 . A light-emitting component according to  claim 3 , wherein the electrode layers comprise indium tin oxide (ITO) or a degenerate oxide other than ITO. 
     
     
         6 . A light-emitting component according to  claim 1 , wherein the cathode includes a metallic intermediate layer adjacent to the subjacent doped, charge-carrier transport layer when the cathode is located on top or the anode includes a metallic intermediate layer adjacent to the subjacent doped, hole transport layer when the anode is located on top and wherein the metallic layer has a nominal thickness between 0.1 nm and 3 nm. 
     
     
         7 . A light-emitting component according to  claim 1 , wherein no metal layer is located between the doped hole transport layer and the anode when the anode is on top or between the doped electron transport layer and the cathode when the cathode is on top. 
     
     
         8 . A light-emitting component according to  claim 1 , where the anode and cathode are located between the substrate and encapsulation cover and the transparency is at least 70% for each wavelength between at least 400 nm and 800 nm. 
     
     
         9 . A light-emitting component according to  claim 1 , wherein the molar concentration of admixture in the hole transport layer or in the electron transport layer or in both the hole transport layer and the electron transport layer is in the range of 1:100,000 to 1:10, calculated on the ratio of doping molecules to main-substance molecules. 
     
     
         10 . A light-emitting component according to  claim 1 , wherein the molar concentration of admixture in the hole transport layer or in the electron transport layer, or in both the hole transport layer and the electron transport layer, is at least 1 wt %, calculated on the ratio of doping molecules to main-substance molecules. 
     
     
         11 . A light-emitting component according to  claim 2 , wherein the thickness of each of the hole transport layer or the electron transport layer, of the light-emitting layer and of the at least one of a hole-side blocking layer or an electron-side blocking layer lies in the range of 0.1 nm to 50 μm. 
     
     
         12 . A light-emitting component according to  claim 1 , wherein the cathode is in direct contact with a doped transport layer and is facing away from the substrate when the cathode is on top or the anode is in direct contact with a doped transport layer and is facing away from the substrate when the anode is on top and wherein the doped transport layer is a hole transport layer or an electron transport layer. 
     
     
         13 . A light-emitting component according to  claim 1 , wherein the organic n-dopant material is selected from the group consisting of heterocyclic radicals, diradicals, dimers, an oligomer, a polymer, a dispiro compound, and a polycycle thereof, having the structure according to one of the following formulae: 
       
         
           
           
               
               
           
         
       
       wherein structures 3 and 4 have one or more cyclic linkages A and/or A1 and/or A2,
 wherein A, A1 and A2 are selected from the group consisting of carbocyclic, heterocyclic, polycyclic ring systems, and any combination thereof, which may be substituted or unsubstituted, 
 
       
         
           
           
               
               
           
         
       
       wherein A1 and A2 are present individually or together and A1 and A2 are selected as in structures 3 and 4 and T=CR22, CR22R23, N, NR21, O or S, and 
       
         
           
           
               
               
           
         
       
       wherein structure 7 has one or more bridge bonds Z and Z1, Z or Z1, Z1 and Z2, or Z1 or Z2, and Z, Z1 and Z2 are independently selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, sililyl, alkylsililyl, diazo, disulphide, heterocycloalkyl, heterocyclyl, piperazinyl, dialkyl ether, polyether, primary alkylamine, arylamine, polyamine, aryl, and heteroaryl. 
     
     
         14 . A light-emitting component according to  claim 1 , wherein the organic acceptor organic material is a quiniode derivative or a triylidene derivative, with a reduction potential in the range of 0V vs. Fc/Fc+ to 0.4V vs. Fc/Fc + . 
     
     
         15 . A light-emitting component according to  claim 12  or  13 , wherein the n-doped, donor organic material is an asymmetrically substituted phenanthroline with the following structure 
       
         
           
           
               
               
           
         
       
       wherein:
 R1 and R2 are selected from the group consisting of substituted or unsubstituted Aryl, Heteroaryl, and Alkyl; and 
 R3 is selected from the group consisting of H, CN, substituted or unsubstituted Aryl, Heteroaryl, and Alkyl; 
 R4 is selected from the group consisting of H, CN, COOR with R=Alkyl, Heteroalkyl, Aryl or Heteroaryl, substituted or unsubstituted Aryl, Heteroaryl, Alkyl mit C1-C20, and Cycloalkyl mit C3-C20. 
 
     
     
         16 . A light-emitting component according to  claim 12  or  13 , wherein the n-doped, donor organic material has the structure: 
       
         
           
           
               
               
           
         
       
       wherein M is selected from the group consisting of Ti, Zr, Hf. Nb, Re, Sn and Ge, each R is independently selected from the group consisting of hydrogen, C 1 -C 20 -Alkyl, C 1 -C 20 -Alkenyl, C 1 -C 20 -Alkinyl, Aryl, Heteroaryl, Oligoaryl, Oligoheteroaryl, Oligoarylheteroaryl, —OR x , 
       —NR x R y , —SR x , —NO 2 , —CHO, —COOR x , —F, —Cl, —Br, —I, —CN, —NC, —SCN, —OCN, —SOR x , SO 2 R x , and where R x  and R y  are selected from the group consisting of C 1 -C 20 -Alkyl, C 1 -C 20 -Alkenyl, and C 1 -C 20 -Alkinyl. 
     
     
         17 . A light-emitting component according to  claim 12  or  13 , wherein the n-doped, donor organic material has the structure: 
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2 , R 3 , and R 4  are independently selected from the group consisting of H, halogen, CN, substituted or unsubstituted aryl, heteroaryl, alkyl, heteroalkyl, alkoxy, and aryloxy. 
     
     
         18 . A light-emitting component according to  claim 1 , wherein the anode is between the substrate and the at least one light-emitting layer. 
     
     
         19 . A light-emitting component according to  claim 1 , wherein the cathode is between the substrate and the at least one light-emitting layer. 
     
     
         20 . A light-emitting component according to  claim 3 , wherein the electrode layers include different transparent contact materials. 
     
     
         21 . A light-emitting component according to  claim 1 , further comprising a contact-improving layer located between the electron transport layer and cathode and a contact-improving layer located between the anode and the hole transport layer, wherein the contact-improving layers are configured not to prevent charge from passing through. 
     
     
         22 . A light-emitting component according to  claim 1 , further comprising a contact-improving layer located between the electron transport layer and cathode or a contact-improving layer located between the anode and the hole transport layer, wherein the contact-improving layers are configured not to prevent charge from passing through. 
     
     
         23 . A light-emitting component according to  claim 1 , wherein the light-emitting layer includes a mixed layer of several materials. 
     
     
         24 . A light-emitting component according to  claim 1 , wherein the p-doped hole transport layer includes a mixture of an organic main substance and an acceptor doping substance and an acceptor doping substance and the molecular mass of the dopants is greater than 200 g/mole. 
     
     
         25 . A light-emitting component according to  claim 1 , wherein the electron transport layer includes a mixture of an organic main substance and a donor doping substance and an acceptor doping substance and the molecular mass of the dopants is greater than 200 g/mole. 
     
     
         26 . A light-emitting component according to  claim 1 , wherein when the transparent cathode is on top, the transparent cathode includes a transparent protective layer or when the transparent anode is on top, the transparent anode includes a transparent protective layer. 
     
     
         27 . A light-emitting component according to  claim 1 , wherein when the transparent cathode is on top, the transparent cathode includes a metallic intermediate layer adjacent to the subjacent doped charge-carrier transport layer or when the transparent anode is on top, the transparent anode includes a metallic intermediate layer adjacent to the subjacent doped hole transport layer,
 wherein the transparency of the metal intermediate layer in the visible spectral region is at least 75% and the thickness of the metal intermediate layer is between 0.3 nm and 3 nm.   
     
     
         28 . A light-emitting component according to  claim 1 , wherein the sequence of p-doped hole transport layer and transparent anode is repeated. 
     
     
         29 . A light-emitting component according to  claim 1 , wherein the sequence of n-doped electron transport layer and transparent cathode is repeated. 
     
     
         30 . A light-emitting component according to  claim 2 , further comprising a metallic electron-injection-promoting layer located between the doped electron transport layer and either the electron-side blocking layer or the light-emitting layer, wherein the transparency of the metallic electron-injection-promoting layer in the visible spectral region is at least 75%.