Synthesis of Poly[2‐decyloxy‐5‐(4′‐tert‐butylphenyl)‐1,4‐phenylenevinylene] as a Light Emitting Material

Abstract

In this study, a new electroluminescent poly(2-decyloxy-5-(4 0 -tert-butylphenyl)-1,4-phenylene-vinylene) (designated as DBP-PPV) with no tolane-bis -benzyl (TBB) structure defect was prepared by dehydrohalogenation of 1,4-bisbromomethyl-2-decyloxy-5-(4 0 -tert-butylphenyl) benzene (as monomer). The monomer bearing decyloxy and 4 0 -tert-butylphenyl substituents was synthesized via alkylation, bromination and Suzuki coupling reactions. The two asymmetric substituents of the monomer can suppress the formation of TBB defect during polymerization process and make the resultant polymer be soluble in common organic solvents. The structure and properties of DBP-PPV were examined by 1 H-NMR, FT-IR, UV/Vis, TGA and photoluminescence (PL) analyses. Moreover, with the DBP-PPV acting as a lightemitting polymer, a device with sequential lamination of ITO/PEDOT/DBP-PPV/Ca/Ag was fabricated. The electroluminescence (EL) spectrum of the device showed a maximum emission at around 546 nm, corresponding to a yellowish-green light. The device showed a turn-on voltage of about 8.4 V and a maximum luminescence efficiency of 0.11 cd/A at an applied voltage of 12 V.