Heterocyclic compounds and their use in electro-optical or opto-electronic devices

Abstract

In further embodiments there are provided OLEDs or other devices e.g. electrostatic latent image forming members in which improved efficiency is obtained by using as electron transport layers, electron injectors, hosts and emitters (dopants) ambipolar or electron-transmitting compounds in which thianthrene is bonded to aryl e.g. 1-anthracenyl-9-yl-thianthrene, 1-biphenyl-4-yl-thianthrene and 9,10-Bis(1-thianthrenyl) anthracene.

What is claimed is: 
     
         1 . Any of the following compounds:
 (a) 4,4′-Di-(thianthren-2-yl)-triphenylamine useful as a hole transport material, having a highest occupied molecular orbital at −5.7 eV, a lowest unoccupied molecular orbital of −2.4 eV and a glass transition temperature of 122° C.;   (b) 2,8-Bis(1-thianthrenyl)-dibenzothiophene useful as a hole transport material, having a highest occupied molecular orbital at −6.1 eV, a lowest unoccupied molecular orbital of −2.2 eV and a glass transition temperature of 133° C.;   (c) the compound   
       
         
           
           
               
               
           
         
       
       useful as a hole transport material, having a highest occupied molecular orbital at −5.2 eV, a lowest unoccupied molecular orbital of −2.2 eV and a glass transition temperature of 142° C.; or
 (d) 4-(1-thianthrenyl)-bis(triphenyl amine) useful as a hole transport material, having an optical band gap of 3.1 eV and a glass transition temperature of 107° C. 
 
     
     
         2 . A hole transport material comprising a compound according to  claim 1  and a p-dopant which is an acceptor-type organic molecule. 
     
     
         3 . The material of  claim 2 , wherein the dopant is present in an amount such that when the material is deposited to form a layer the dopant contributes about 10-40% to layer thickness. 
     
     
         4 . The material of  claim 2 , wherein:
 (a) the dopant comprises tetracyanoquinodimethane or tetrafluorotetracyano-quinodimethane.   (b) the dopant comprises a compound of any of the general formulae (i)-(vii) below:   
       
         
           
           
               
               
           
         
         wherein the groups R in any of the formulae in (i) to (vii) can be the same or different and are selected from hydrogen; substituted and unsubstituted aliphatic groups; substituted and unsubstituted aromatic, heterocyclic and polycyclic ring structures; halogens; and thiophenyl groups; and wherein 
         in formula (i) the methyl groups may be replaced by C 1 -C 4  alkyl or monocyclic or polyclic aryl or heteroraryl which may be further substituted e.g. with alkyl, aryl or arylamino, or of the formula viii or ix 
       
       
         
           
           
               
               
           
         
         wherein the groups R 1 -R 4  when appearing in either of the above formulae can be the same or different and are selected from hydrogen; substituted and unsubstituted aliphatic groups; substituted and unsubstituted aromatic, heterocyclic and polycyclic ring structures; halogens; and thiophenyl groups. 
         (c) the dopant comprises a tertiary amine which is α-NPB or β-NBP. 
       
     
     
         5 . An optical light-emitting diode having first and second electrodes and between said electrodes a layer comprising a compound as claimed in  claim 1 . 
     
     
         6 . The diode of  claim 5 , wherein said layer is a hole transport layer. 
     
     
         7 . The diode of  claim 6 , having an emissive layer comprising an emitter selected from:
 (a) a fluorescent emitter;   (b) a phosphorescent emitter;   (c) an ion fluorescent (rare earth based) emitter;   (d) quantum dots; and   (e) thermally activated fluorescent (TADF) materials.   
     
     
         8 . The diode of  claim 5 , having a hole injection layer comprising CuPC, ZnTpTP, 2-TNATA or 
       
         
           
           
               
               
           
         
       
     
     
         9 . The diode of  claim 5 , which forms part of a flat panel display, a lighting panel, or an organic photovoltaic device. 
     
     
         10 . An imaging member for forming an electrostatic latent image, an organic thin film transistor, a dye-sensitised solar cell, a printed device or a quantum dot based electroluminescent device comprising a compound as claimed in  claim 1 . 
     
     
         11 . An OLED device used as a light source to print conductive, resistive, dielectric, piezoelectric or pyroelectric films or lines or grids, said device comprising a compound as claimed in  claim 1 . 
     
     
         12 . An OLED lighting panel comprising a compound as claimed in  claim 1 .