Organic Thin Film Ink Compositions and Methods

Abstract

The present teachings relate to various embodiments of an ink composition, which once printed and cured forms an organic thin film on a substrate such as, but not limited by, an OLED device substrate. Various embodiments of the ink can be printed using an industrial inkjet printing system that can be housed in a gas enclosure, which gas enclosure defines an interior that has a controlled environment maintained as an inert and substantially low-particle process environment. Patterned printing of an organic thin film on a substrate, for example, but not limited by, an OLED device substrate, in such a controlled environment can ensure a high-volume, high yield process for a variety of OLED devices.

What is claimed is: 
     
         1 . An organic light emitting device comprising:
 an optoelectronic device substrate; and   an encapsulation layer over the optoelectronic device substrate, the encapsulation layer comprising a polymeric film comprising:
 75-95 wt. % polymerized polyethylene glycol dimethacrylate monomer, polymerized polyethylene glycol diacrylate monomer, or a combination thereof; 
 4-10 wt. % polymerized pentaerythritol tetraacrylate, polymerized pentaerythritol tetramethacrylate, or a combination thereof; and 
 1-15 wt. % of a polymerized spreading modifier, the spreading modifier having a viscosity in the range from about 14 to about 18 cps at 22° C. and a surface tension in the range from about 35 to about 39 dynes/cm at 22° C. in its unpolymerized state. 
   
     
     
         2 . The device of  claim 1 , wherein the optoelectronic device substrate is an organic light emitting device substrate comprising: an anode, a cathode, and a light emissive layer. 
     
     
         3 . The device of  claim 1 , wherein the encapsulation layer further comprises a layer of inorganic material adjacent to the polymeric film. 
     
     
         4 . The device of  claim 3 , wherein the inorganic material is a metal oxide. 
     
     
         5 . The device of  claim 1 , wherein the spreading modifier has a viscosity in the range from about 14 to about 16 cps at 22° C. and a surface tension in the range from about 35 to about 38 dynes/cm at 22° C. in its unpolymerized state. 
     
     
         6 . The device of  claim 1 , wherein the polymerized spreading modifier comprises a polymerized alkoxylated aliphatic diacrylate monomer, a polymerized alkoxylated aliphatic dimethacrylate monomer, or a combination thereof. 
     
     
         7 . The device of  claim 5 , wherein the polymerized spreading modifier comprises a polymerized alkoxylated aliphatic diacrylate monomer, a polymerized alkoxylated aliphatic dimethacrylate monomer, or a combination thereof. 
     
     
         8 . The device of  claim 1 , wherein the polymeric film comprises 75-95 wt. % polymerized polyethylene glycol dimethacrylate monomer having a number average molecular weight of about 330 g/mole, and 4-10 wt. % polymerized pentaerythritol tetraacrylate. 
     
     
         9 . The device of  claim 8 , wherein the spreading modifier comprises polymerized alkoxylated aliphatic diacrylate monomer. 
     
     
         10 . The device of  claim 1 , wherein the polymeric film comprises 85-95 wt. % polymerized polyethylene glycol dimethacrylate monomer, polymerized the polyethylene glycol diacrylate monomer, or the combination thereof.