화학공학소재연구정보센터
Polymer(Korea), Vol.29, No.4, 357-362, July, 2005
주사슬에 설폰기를 함유하는 전기발광 공액 고분자의 합성과 특성분석
Synthesis and Characterizqation of Electroluminescent Conjugated Polymers Containing Sulfone Group in the Main Chain
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초록
중합체의 공액길이를 제어하고 이들이 갖는 에너지 준위를 조절하며, 발광성능향상과 발광파장을 조절하려는 목저긍로 설폰기가 포함된 페닐렌-비닐렌계의 새로운 전기발광 고분자들을 Wittig 중합을 통해 합성하였다. 합성된 고분자들은 일반 유기 용매에 좋은 용해성을 보였고 400 ℃ 정도의 초기분해온도와 200 ℃ 전후의 높은 유리전이온도를 가짐으로써 열적 안정성이 매우 높음을 확인하였다. 각각의 고분자는 용액과 필름상태에서 모두 설폰기의 꺾임에 의해 공액길이가 짧아질수록 UV 흡수와 발광 스펙트럼이 단파장으로 이동하였고 이를 통해 설폰기가 효율적으로 발광파장을 제어하는 것을 확인하였다. 또한 CV 측정과 이론적인 계산을 통해 전자친화도가 큰 설폰기에 의해서 합성된 고분자들의 HOMO 및 LUMO 에너지 준위가 상대적으로 낮아짐으로써 소자의 전기발광특성이 향상됨을 확인하였다.
As a new class of electroluminescent (EL) polymers, PPV-based polymers containing sulfone group in the main chain were synthesized through Witting polymerization reaction to control π-conjugation length and energy levels for predictable light emission and enhanced device performance. These EL polymers showed good solubility in common organic solvents and high thermal stability with initial decomposition temperature of ca. 400 ℃ and glass transition temperature around 200 ℃. Emission colors were tuned from green to deep blue by reducing π-conjugated length between sulfone groups. It was also noted from the cyclic voltammetry (CV) measurements and semiempirical calculations that sulfone group with high electron affinity effectively lowered HOMO-LUMO energy levels to enhance EL device performance.
  1. Saleh BEA, Teich MC, Fundamentals of Photonics, John Wiley & Sons, New York (1991)
  2. Mooney WJ, Optoelectric Devices and Principles, Prentice Hall, New Jersey (1991)
  3. Bhattacharya P, Semiconductor Optoelectronic Devices, Prentice Hall, new Jersey (1994)
  4. Burroughes JH, Bradley DDC, Brown AR, Marks RN, Mackay K, Friend RH, Burn PL, Holmes AB, Nature, 347, 539 (1990) 
  5. Tessler N, Denton GJ, Friend RH, Nature, 382(6593), 695 (1996) 
  6. Lu JP, Tao Y, D'iorio M, Li YN, Ding JF, Day M, Macromolecules, 37(7), 2442 (2004) 
  7. Kraft A, Grimsdale AC, Holmes AB, Angew. Chem.-Int. Edit., 37, 402 (1998) 
  8. Salbeck J, Ber. Bunsenges. Phys. Chem., 100, 1667 (1996)
  9. Killeen KA, Thomson ME, J. Appl. Phys., 91, 6717 (2002) 
  10. Antoniadis H, Abkowitz MA, Hsieh BR, Appl. Phys. Lett., 65, 2030 (1994) 
  11. Blom DWM, Dejong MJM, Vleggaar JJM, Appl. Phys. Lett., 68, 308 (1996) 
  12. Parker ID, J. Appl. Phys., 75, 1656 (1994) 
  13. Fou AC, Onitsuka O, Ferreira M, Rubner MF, Hsieh BR, J. Appl. Phys., 79, 7501 (1996) 
  14. Strukelj M, Jordan RH, Dodabalapur A, J. Am. Chem. Soc., 118(5), 1213 (1996) 
  15. Greenham NC, Moratil SC, Bradley DDC, Friend RH, Holmes AB, Nature, 365, 628 (1993) 
  16. Jin SH, Koo DS, Hwang CK, Do JY, Kim YI, Gal YS, Lee JW, Hwang JT, Macromol. Res., 13(2), 114 (2005)
  17. Parker ID, Pei Q, Marrocco M, Appl. Phys. Lett., 65, 1272 (1994) 
  18. Jin Y, Kim J, Park SH, Lee K, Suh H, Bull. Korean Chem. Soc., 26, 795 (2005)
  19. Kim JH, Lee H, Bull. Korean Chem. Soc., 25, 652 (2004)
  20. Zyung T, Jung S, Hwang DH, Synth. Met., 117, 223 (2001) 
  21. Klessinger M, Michl J, Excited States and Photochemistry of Organic Molecules, VCH (1995)
  22. Baigent DR, Holmes AB, Moratti SC, Friend RH, Synth. Met., 80, 199 (1996)
  23. Jenekhe SA, Adv. Mater., 7, 309 (1995) 
  24. Fox MA, Farid S, Science, 226, 917 (1984) 
  25. Zhang C, Braun D, Heeger AJ, J. Appl. Phys., 73, 5177 (1993) 
  26. Tasch S, Niko A, Leising G, Scherf U, Appl. Phys. Lett., 68, 1090 (1996) 
  27. Berggren M, Gustafsson G, Inganas O, Andersson MR, Wennerstrom O, Hjertberg T, Adv. Mater., 2, 488 (1994) 
  28. Hwang DH, Kang IN, Jang MS, Shim HK, Zyong T, Polym. Bull., 36(3), 383 (1996)