In an attempt to improve the Electroluminescence(EL) efficiency of an organic polymer, a copolymer of 3-octylthiophene and 3-(4-flurophenyl)thiophene was synthesized. The electrical and optical characteristics of the copolymer was investigated by measuring the Photolumine-scence(PL) and EL spectra as well as the I-V-L curves. The λ(max) (651 nm) in the PL spectrum of poly(3-octylthiophene-co-3-(4-fluorophenyl)thiophene) (2:1)[P(OT/FPT) (2:1)] film was red-chifted by 21 nm compared with that of the solution in chloroform which is smaller by 12 nm than the red-shift in poly(3-octylthiophene) (POT). This indicates that the excimer formation is less prominent in P(OT/FPT) (2:1) than in POT. It is believed that the color purity was improved due to the high hole transport capability of polythiophene and the electron withdrawing characteristics of 4-fluorophenyl group. This leads to the efficient injection of electrons and eventually to the lower operating voltage, i.e 6 V, and improvement of the intensity of theEL device using P(OT/FPT) (2:1).

3-Octylthiophene과 3-(4-fluorophenyl)thiophene을 공중합하여 발광 효율과 색순도가 우수한 유기 전기 발광 고분자를 개발하였다. 공중합한 고분자의 전기·광학적 특성을 Photoluminescence(PL), Electroluminescence(EL) 스펙트럼과 유기 전기 발광 소자의 I-V, V-L 곡선을 이용하여 조사하였다. poly(3-octylthiophene-co-3-(4-fluorophenyl)thiophene) (2:1)[P(OT/FPT) (2:1)]의 PL 필름 스펙트럼에서 최대 발광 파장 (651 nm)이 용액의 그것에 비하여 21 nm 만큼 적색 이동하였는데, 그 크기가 poly(3-octylthiophene) (POT)에 비해 12 nm 정도 적게 일어났다. 이는 p(OT/FPT) (2:1)에서 excimer complex의 영향이 적음을 의미한다. Polythiophene의 우수한 정공 전달 능력과 4-fluorophenyl 기의 전자 끌기에 의해 전자 주입이 용이해져 P(OT/FPT) (2:1)의 구동 전압이 6 V로 낮아지고 색순도가 개선되었으며 발광 세기가 증가된 것으로 믿어진다.