Fluorosurfactant-Containing Ink Compositions for Inkjet Printing

Abstract

Ink compositions formulated for inkjet printing the hole injecting layer (HIL) or hole transporting layer (HTL) of an organic light emitting diode (OLED) are provided. The ink compositions comprise fluorosurfactants that prevent uncontrolled spreading of the printed ink compositions. Also provided are methods of inkjet printing the HILs or HTLs using the ink compositions.

What is claimed is: 
     
         1 . A method of forming a hole injecting layer or a hole transporting layer for an organic light emitting diode, the method comprising:
 inkjet printing a droplet of an ink composition over an electrode layer in a pixel cell of an organic light emitting diode pixel bank, the ink composition comprising:
 a hole injection material or a hole transporting material; 
 one or more organic solvents that solubilize the hole injection material or hole transporting material; and 
 a fluorosurfactant; 
 wherein the fluorosurfactant is present in an amount of no greater than 5 wt. %, based on the total weight of the ink composition; and 
   allowing the volatile components of the ink composition to evaporate, whereby the hole injecting layer or hole transporting layer is formed.   
     
     
         2 . The method of  claim 1 , wherein the fluorosurfactant is present in an amount of no greater than 1 wt. %, based on the total weight of the ink composition. 
     
     
         3 . The method of  claim 1 , wherein the fluorosurfactant is present in an amount of no greater than 0.15 wt. %, based on the total weight of the ink composition. 
     
     
         4 . The method of  claim 1 , wherein the fluorosurfactant is a fluorotelomer. 
     
     
         5 . The method of  claim 1 , wherein the ink composition comprises 95 to 99.8 wt. % organic solvent and 0.03 to 0.1 wt. % fluorosurfactant. 
     
     
         6 . The method of  claim 5 , wherein the fluorosurfactant is a fluorotelomer. 
     
     
         7 . The method of  claim 1 , wherein the ink composition comprises a hole injection material comprising an electrically conductive polythiophene. 
     
     
         8 . The method of  claim 7 , wherein the fluorosurfactant is a fluorotelomer. 
     
     
         9 . The method of  claim 8 , wherein the fluorotelomer is present in an amount of no greater than 0.15 wt. %, based on the total weight of the ink composition. 
     
     
         10 . The method of  claim 1 , wherein the ink composition comprises a hole transporting material selected from polyvinyl carbazoles or derivatives thereof, polysilanes or derivatives thereof, polysiloxane derivatives having an aromatic amine at the side chain or the main chain, pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives, polyaniline or derivatives thereof, polythiophene or derivatives thereof, polyarylamines or derivatives thereof, polypyrroles or derivatives thereof, poly(p-phenylenevinylene) or derivatives thereof, or poly(2,5 thienylene vinylene) or derivatives thereof. 
     
     
         11 . The method of  claim 10 , wherein the fluorosurfactant is a fluorotelomer. 
     
     
         12 . The method of  claim 11 , wherein the fluorotelomer is present in an amount of no greater than 0.15 wt. %, based on the total weight of the ink composition. 
     
     
         13 . The method of  claim 10 , wherein the ink composition further comprises methicone. 
     
     
         14 . The method of  claim 13 , wherein the one or more organic solvents comprises an aprotic solvent. 
     
     
         15 . The method of  claim 10 , wherein the one or more organic solvents comprises an aprotic solvent. 
     
     
         16 . A film comprising:
 a hole injection material or a hole transporting material; and
 a fluorosurfactant. 
   
     
     
         17 . The film of  claim 16 , wherein the fluorosurfactant is a fluorotelomer. 
     
     
         18 . The film of  claim 16  comprising the hole injection material, wherein the hole injection material is an electrically conductive polythiophene. 
     
     
         19 . An organic light emitting diode comprising a hole injection layer or a hole transporting layer, the hole injection layer or hole transporting layer comprising:
 a hole injection material or a hole transporting material; and   a fluorosurfactant.   
     
     
         20 . The organic light emitting diode of  claim 19 , wherein the fluorosurfactant is a fluorotelomer.