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 max,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.