분자 자기 집합체 현상에 의한 폴리 페닐렌 비닐렌 다층 박막의 광전자적 특성

김두식; 차국헌; 홍종달; 유승한; 진정일

Polymer(Korea), Vol.20, No.6, 915-924, November, 1996

Export Citation

분자 자기 집합체 현상에 의한 폴리 페닐렌 비닐렌 다층 박막의 광전자적 특성

Photoelectronic Characteristics of Poly(p-phenylene vinylene) in Self-Assembled Multilayer Films

김두식, 차국헌, 홍종달, 유승한, 진정일

초록

양이온과 음이온 고분자 전해질 사이의 정전기적 인력을 이용한 분자 자기 집합체 (self-as-sembly, SA) 방법으로 고분자를 적절한 다층 박막으로 가공할 수가 있었다. Poly(p-phenylenevinylene) (PPV) 선구체 (precursor)와 poly(sodium 4-styrenesulfonate) (PSS)의 SA 박막을 만들어 그 성장 양상과 열전환 후 공액 길이 및 photoluminescence (PL) 스펙트럼 변화를 spin-coating한 PPV 박막과의 비교를 통해 알아보았다. PPV 선구체/PSS 다충 박막은 적층된 층수에 비례하는, 안정된 박막 성장을 보여 주었다. 공액 구조로의 열전환이 spin-coating한 박막과는 매우 다르게 관찰되어, SA 과정에서 PPV 선구체에 부여된 사슬 구조상의 제한 요소가 공액 길이 및 그 분포를 제한함을 알 수 있었다. 또한 SA 박막은 그 공액 길이에 관계없이 거의 일정한 PL 스펙트럼을 나타내었으며, 그 방출 파장 및 모양도 spin-coating한 PPV 박막과는 큰 차이가 있었다. 이러한 SA 박닥의 PL 특성은 박막내 PPV 사슬간의 exciton 이송이 PSS에 의해 방해받기 때문인 것으로 추정되었다.

Self-assembly (SA) technique based on the electrostatic interactions between cationic and anionic polyelectrolytes provided a viable means to fabricate polymers into multilayer thin films. The self-assembled films made from poly(p-phenylene vinylene) (PPV) precursor and poly(sodium 4-styrenesulfonate) (PSS) were prepared, and their layer-by-layer growth and the changes of the conjugation lengths and the photoluminescence (PL) spectra after annealing were compared with those of spin-coated bulk PPV films. PPV precursor/PSS multilayer thin films showed stable growth behavior proportional to the number of deposition. The observed thermal conversion behavior toward the conjugated structure in the self-assembled films which was quite different from that of spin-coated films suggests that the conformational constraint on PPV precursor chains imposed by self-assembling process imparts limitation of conjugation length and its distribution. The self-assembled films with different conjugation lengths were also found to demonstrate almost the same PL spectra, whose, emission wavelength and shape were quite different from those of the spin-coated PPV films. It is believed that such PL spectral characteristics of the self-assembled films are due to the hindrance on exciton migrations between PPV chains (or layers) which is caused by PSS chains (or layers).

Keywords:self-assembly(SA) technique;poly(p-phenylene vinylene) (PPV);conjugation length;photoluminescence;conformational constraint;exciton migration

[References]

Heeger AJ, Kivelson S, Schrieffer JR, Su WP, Rev. Mod. Phys., 60, 781 (1988)
Bredas JL, Chance RR, "Conjugated Polymeric Materials: Opportunities in Electronics, Optoelectronics and Molecular Electronics," Klewer Academics, Dordrecht (1990)
Salaneck WR, Lundstrom I, Ranby B, "Conjugated Polymers and Related Materials," Oxford, New York (1993)
Burroughes JH, Bradley DDC, Brown AR, Marks RN, Mackay K, Friend RH, Burn PL, Holms AB, Nature, 347, 477 (1990)
Gustafsson G, Cao Y, Treacy GM, Klavettler F, Colaneri N, Heeger AJ, Nature, 357, 477 (1992)
Sheats JR, Antoniadis H, Hueschen M, Leonard W, Miller J, Moon R, Roitman D, Stocking A, Science, 273(5277), 884 (1996)
Swalen JD, Allara DL, Andrade JD, Chandross EA, Garoff S, Israelachivili J, McCarthy TJ, Murray R, Pease RF, Rabolt JF, Wynne KJ, Yu H, Langmuir(3), 932 (1987)
Ulman A, "An Introduction to Ultrathin Organic Films from Langmuir-Blodgett to Self-Assembly," Academic, San Diego (1991)
Roberts G, "Langmuir-Blodgett Films," Plenum, New York (1990)
Lvov Y, Decher G, Mohwald H, Langmuir, 9, 481 (1993)
Hong JD, Decher G, Schmitt J, Thin Solid Films, 210-211, 831 (1992)
Fleer GJ, CohenStuart MA, Scheutjens JMHM, Consgrove T, Vincent B, "Polymers at Interfaces," Champman & Hall, London (1993)
Ferreira M, Rubner MF, Macromolecules, 28(21), 7107 (1995)
Hong H, Tarabia M, Chayet H, Davidov D, Faraggi EZ, Anvy Y, Neumann R, Kirstein S, J. Appl. Phys., 79, 3082 (1996)
Onoda M, Yoshino K, J. Appl. Phys., 78, 4456 (1995)
Lenz RW, Han CC, Stenger-Smith JD, Karasz FE, J. Polym. Sci. A: Polym. Chem., 26, 3241 (1988)
Gagnon DR, Gapistran JD, Karasz FE, Lenz RW, Antoun S, Polymer, 28, 570 (1987)
Lakowicz JR, "Principles of Fluorescence Spectroscopy," Plenum, New York (1984)
Turro NJ, "Modern Molecular Photochemistry," Benjamin/Cummings, Menlo Park (1978)
Gray RO, Baier U, Bubeck C, Mullen K, Adv. Mater., 5, 561 (1993)
Son S, Dodabalapur A, Lovinger AJ, Galvin ME, Science, 269(5222), 376 (1995)
Jacobs S, Eevers W, Verreyt G, Geise HJ, DeGroot A, Dommisse R, Synth. Met., 61, 189 (1993)
Heun S, Mahrt RF, Greiner A, Lemmer U, Bassler H, Halliday DA, Bradley DDC, Burn PL, Holms AB, J. Phys.: Condens. Matter, 5, 247 (1993)
Stegner-Smith JD, Lenz RW, Wegner G, Polymer, 30, 1048 (1989)
Pichler K, Halliday DA, Bradley DDC, Burn PL, Friend RH, Holms AB, J. Phys.: Condens. Matter, 5, 7155 (1993)
Bradley DDC, J. Phys. D: Appl. Phys., 20, 1389 (1987)
Burn PL, Holms AB, Kraft A, BradleyDDC, Brown AR, Friend RH, J. Chem. Soc.-Chem. Commun., 32 (1992)

[1] Heeger AJ, Kivelson S, Schrieffer JR, Su WP, Rev. Mod. Phys., 60, 781 (1988)

[2] Bredas JL, Chance RR, "Conjugated Polymeric Materials: Opportunities in Electronics, Optoelectronics and Molecular Electronics," Klewer Academics, Dordrecht (1990)

[3] Salaneck WR, Lundstrom I, Ranby B, "Conjugated Polymers and Related Materials," Oxford, New York (1993)

[4] Burroughes JH, Bradley DDC, Brown AR, Marks RN, Mackay K, Friend RH, Burn PL, Holms AB, Nature, 347, 477 (1990)

[5] Gustafsson G, Cao Y, Treacy GM, Klavettler F, Colaneri N, Heeger AJ, Nature, 357, 477 (1992)

[6] Sheats JR, Antoniadis H, Hueschen M, Leonard W, Miller J, Moon R, Roitman D, Stocking A, Science, 273(5277), 884 (1996)

[7] Swalen JD, Allara DL, Andrade JD, Chandross EA, Garoff S, Israelachivili J, McCarthy TJ, Murray R, Pease RF, Rabolt JF, Wynne KJ, Yu H, Langmuir(3), 932 (1987)

[8] Ulman A, "An Introduction to Ultrathin Organic Films from Langmuir-Blodgett to Self-Assembly," Academic, San Diego (1991)

[9] Roberts G, "Langmuir-Blodgett Films," Plenum, New York (1990)

[10] Lvov Y, Decher G, Mohwald H, Langmuir, 9, 481 (1993)

[11] Hong JD, Decher G, Schmitt J, Thin Solid Films, 210-211, 831 (1992)

[12] Fleer GJ, CohenStuart MA, Scheutjens JMHM, Consgrove T, Vincent B, "Polymers at Interfaces," Champman & Hall, London (1993)

[13] Ferreira M, Rubner MF, Macromolecules, 28(21), 7107 (1995)

[14] Hong H, Tarabia M, Chayet H, Davidov D, Faraggi EZ, Anvy Y, Neumann R, Kirstein S, J. Appl. Phys., 79, 3082 (1996)

[15] Onoda M, Yoshino K, J. Appl. Phys., 78, 4456 (1995)

[16] Lenz RW, Han CC, Stenger-Smith JD, Karasz FE, J. Polym. Sci. A: Polym. Chem., 26, 3241 (1988)

[17] Gagnon DR, Gapistran JD, Karasz FE, Lenz RW, Antoun S, Polymer, 28, 570 (1987)

[18] Lakowicz JR, "Principles of Fluorescence Spectroscopy," Plenum, New York (1984)

[19] Turro NJ, "Modern Molecular Photochemistry," Benjamin/Cummings, Menlo Park (1978)

[20] Gray RO, Baier U, Bubeck C, Mullen K, Adv. Mater., 5, 561 (1993)

[21] Son S, Dodabalapur A, Lovinger AJ, Galvin ME, Science, 269(5222), 376 (1995)

[22] Jacobs S, Eevers W, Verreyt G, Geise HJ, DeGroot A, Dommisse R, Synth. Met., 61, 189 (1993)

[23] Heun S, Mahrt RF, Greiner A, Lemmer U, Bassler H, Halliday DA, Bradley DDC, Burn PL, Holms AB, J. Phys.: Condens. Matter, 5, 247 (1993)

[24] Stegner-Smith JD, Lenz RW, Wegner G, Polymer, 30, 1048 (1989)

[25] Pichler K, Halliday DA, Bradley DDC, Burn PL, Friend RH, Holms AB, J. Phys.: Condens. Matter, 5, 7155 (1993)

[26] Bradley DDC, J. Phys. D: Appl. Phys., 20, 1389 (1987)

[27] Burn PL, Holms AB, Kraft A, BradleyDDC, Brown AR, Friend RH, J. Chem. Soc.-Chem. Commun., 32 (1992)