Photosensitive ink compositions and transparent conductors and method of using the same

Abstract

This disclosure is related to photosensitive ink compositions comprising conductive nanostructures and a photosensitive compound, and method of using the same.

1 . A method comprising:
 forming a thin film of interconnecting conductive nanostructures on a substrate, wherein the forming comprises:
 depositing an ink composition on the substrate, wherein the ink composition comprises a plurality of conductive nanostructures, a binding material, a heat-activatable photosensitive compound, and a polar solvent; and 
 removing the polar solvent; 
   placing a mask above the thin film, wherein the mask comprises an opening and defines the thin film into a masked region and an unmasked region, wherein the unmasked region underlies the opening;   exposing the thin film to an ultra violet (UV) light source through the opening of the mask at a first temperature to cause photo-degradation of the heat-activatable photosensitive compound in the unmasked region; and   exposing the thin film to a heat source in a dark environment at a second temperature to cause thermal-degradation of the heat-activatable photosensitive compound in the masked region.   
     
     
         2 . The method of  claim 1 , wherein the second temperature is higher than the first temperature. 
     
     
         3 . The method of  claim 1 , wherein a difference between haze of the masked region and haze of the unmasked region after exposing the thin film to the heat source is no more than 10%. 
     
     
         4 . The method of  claim 1 , wherein a difference between light transmission of the masked region and light transmission of the unmasked region after exposing the thin film to the heat source is no more than 10%. 
     
     
         5 . The method of  claim 1 , wherein:
 a difference between haze of the masked region and haze of the unmasked region after exposing the thin film to the heat source is no more than 10%, and   a difference between light transmission of the masked region and light transmission of the unmasked region after exposing the thin film to the heat source is no more than 10%.   
     
     
         6 . The method of  claim 1 , wherein a subset of the plurality of conductive nanostructures in the masked region remain present after exposing the thin film to the heat source. 
     
     
         7 . The method of  claim 1 , wherein the photo-degradation of the heat-activatable photosensitive compound does not cause structural damage to a subset of the plurality of conductive nanostructures in the unmasked region. 
     
     
         8 . The method of  claim 7 , wherein the thermal-degradation of the heat-activatable photosensitive compound causes structural damage to a subset of the plurality of conductive nanostructures in the masked region but not to the subset of the plurality of conductive nanostructures in the unmasked region. 
     
     
         9 . The method of  claim 1 , wherein the thermal-degradation of the heat-activatable photosensitive compound causes structural damage to a subset of the plurality of conductive nanostructures in the masked region. 
     
     
         10 . The method of  claim 1 , wherein, after exposing the thin film to the UV light source and exposing the thin film to the heat source, the unmasked region is more conductive than the masked region. 
     
     
         11 . The method of  claim 1 , wherein the heat-activatable photosensitive compound is a photo acid generator. 
     
     
         12 . The method of  claim 1 , wherein the heat-activatable photosensitive compound comprises at least one of a diaryl iodonium salt, a triaryl sulfonium salt, or a diazonium salt. 
     
     
         13 . The method of  claim 1 , wherein:
 the heat-activatable photosensitive compound comprises a diphenyliodonium salt, and   a counter ion of the diphenyliodonium salt is chloride, nitrate, tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate, or hexafluoroantimonate.   
     
     
         14 . The method of  claim 1 , wherein the heat-activatable photosensitive compound comprises at least one of 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, N-hydroxynaphthalimide triflate, or N-hydroxy-5-norbornene-2,3-dicarboximide perfluoro-1-butanesulfonate. 
     
     
         15 . A method comprising:
 forming a thin film of interconnecting conductive nanostructures on a substrate, wherein the forming comprises:
 depositing an ink composition on the substrate, wherein the ink composition comprises a plurality of conductive nanostructures, a binding material, a heat-activatable photosensitive compound, and a polar solvent; and 
 removing the polar solvent; 
   placing a mask above the thin film, wherein the mask comprises an opening and defines the thin film into a masked region and an unmasked region, wherein the unmasked region underlies the opening;   destroying the heat-activatable photosensitive compound in the unmasked region; and   degrading the heat-activatable photosensitive compound in the masked region after destroying the heat-activatable photosensitive compound in the unmasked region, wherein degradation of the heat-activatable photosensitive compound causes a change in a conductivity of a subset of the plurality of conductive nanostructures in the masked region such that the subset of the plurality of conductive nanostructure in the masked region has a first conductivity prior to degrading the heat-activatable photosensitive compound and has a second conductivity after degrading the heat-activatable photosensitive compound, wherein the second conductivity is different than the first conductivity.   
     
     
         16 . The method of  claim 15 , wherein the second conductivity is less than the first conductivity. 
     
     
         17 . The method of  claim 15 , wherein:
 destroying the heat-activatable photosensitive compound comprises exposing the unmasked region to ultra violet (UV) light; and   degrading the heat-activatable photosensitive compound in the masked region comprises exposing the thin film to a heat source.   
     
     
         18 . The method of  claim 17 , wherein exposing the thin film to the heat source comprises exposing the thin film to the heat source in a dark environment. 
     
     
         19 . A method comprising:
 forming a thin film of interconnecting conductive nanostructures on a substrate, wherein the thin film comprises a plurality of conductive nanostructures, a binding material, and a heat-activatable photosensitive compound;   concealing a portion of the thin film to define a masked region, wherein a portion of the thin film that is not concealed is defined as an unmasked region;   performing a first operation on the heat-activatable photosensitive compound in the unmasked region but not on the heat-activatable photosensitive compound in the masked region; and   performing a second operation on the heat-activatable photosensitive compound after performing the first operation, wherein a response to the second operation of the heat-activatable photosensitive compound in the masked region is different than a response to the second operation of the heat-activatable photosensitive compound in the unmasked region due to the first operation being performed on the heat-activatable photosensitive compound in the unmasked region.   
     
     
         20 . The method of  claim 19 , wherein the first operation is performed using a light source and the second operation is performed using a heat source.