Synthesis and Photoluminescent Properties of Red Phosphorescent Random Copolymers with Photopatternable Moiety

Abstract

Two types of photopatternable blue emitting random copolymers, poly(VK-ran-CEMA) ( 1 ) and poly(VK-ran-CEMA-ran-MAE) ( 2 ), containing UV curable cinnamoyl moieties capable of generating negative type patterned images were synthesized and characterized. In addition, their potential possibility to be used as a photopatternable polymeric host matrix for a red phosphorescent dopant was studied by using UV-Visible absorption and PL emission spectroscopy. The λmax,PL value of poly(VK-ran-CEMA) ( 1 ) doped with a red phosphorescent dopant, (bsn)2Ir(acac), was shifted from 343 nm of poly(VK-ran-CEMA) ( 1 ) to 610 nm, with increasing the content of (bsn)2Ir(acac). Poly(VK-ran-CEMA-ran-(bsn)2IrMAE) ( 3 ), prepared by the reaction of [(bsn)2IrCl]2 with poly(VK-ran-CEMA-ran-MAE) ( 2 ), exhibited λmax,PL at 610 nm in the range of red emission. These results implied efficient energy transfer from photopatternable blue emitting random copolymers to a red phosphorescent dopant. It was also found upon UV exposure on the synthesized copolymers that negative patterned images with high resolution were produced by standard photolithographic process.