• Electron Injection Mechanisms Varied by Conjugated Polyelectrolyte Electron Transporting Layers in Polymer Light-Emitting Diodes
  • Um SS, Park J
  • 고분자 발광다이오드에서 공액고분자 전해질 전자수송층에 의해 변화되는 전자주입 메카니즘
  • 엄성수, 박주현
Abstract
Capacitance measurements of the polymer light-emitting diodes (PLEDs) with conjugated polyelectrolyte (CPE) electron transporting layers (ETLs) provide important information of device physics for understanding the function of CPEs as ETLs, together with current density-voltage-luminescence measurements. We investigated the counteriondependent capacitance behaviors that present a highly negative or positive capacitance at the low frequency, and suggested different carrier injection mechanisms. Capacitance model study reveals that the electron injection mechanism can be described either by the dipole alignment scheme or by electronic charge carrier accumulation at the cathode/ETL/emission layer interfaces.

공액고분자 전해질 전자수송층을 이용하는 고분자 발광소자의 정전용량을 측정하는 것은 전류밀도-전압-발광 특성을 측정하는 방법과 더불어 전자수송층으로서 공액고분자 전해질의 기능을 이해하기 위한 소자물리 연구에서 중요한 정보를 제공해준다. 본 연구에서는 고분자 전해질의 반대 이온의 종류에 따라 저주파수 영역에서 정전용량의 거동이 변화하는 것으로부터 전하 주입의 메카니즘에서 차이점이 있음을 분석하였다. 정전용량 모델을 이용한 분석은 전자주입 메카니즘이 음극/전자수송층/발광층 사이의 계면에서 발생하는 쌍극자 배열 또는 전하수송체의 축적에 의한 것임을 나타내었다.

Keywords: conjugated polyelectrolyte; polymer light-emitting diode; electron injection; device capacitance.

References
  • 1. Parker ID, J. Appl. Phys., 75, 1665 (1994)
  •  
  • 2. Kim S, Jackiw J, Robinson E, Schanze KS, Reynolds JR, Baur J, Rubner MF, Boils D, Macromolecules, 31(4), 964 (1998)
  •  
  • 3. Park KN, Kang HS, Senthilkumar N, Park DW, Choe Y, Polym.(Korea), 33(5), 407 (2009)
  •  
  • 4. Lee CH, Kim SW, Oh SY, Polym.(Korea), 26(4), 543 (2002)
  •  
  • 5. Oh SY, Kim HM, Lee CH, Choi JW, Rhee HW, Kim HS, Polym.(Korea), 24(1), 90 (2000)
  •  
  • 6. Park LS, Shin KS, Kim SJ, Shin DS, Polym.(Korea), 21(4), 590 (1997)
  •  
  • 7. Park J, Kwon Y, Lee TW, Macromol. Rapid Commun., 28(12), 1366 (2007)
  •  
  • 8. Huang F, Hou LT, Wu HB, Wang XH, Shen HL, Cao W, Yang W, Cao Y, J. Am. Chem. Soc., 126(31), 9845 (2004)
  •  
  • 9. Ishii H, Sugiyama K, Ito E, Seki K, Adv. Mater., 11(8), 605 (1999)
  •  
  • 10. Campbell IH, Smith DL, Ferraris JP, Appl. Phys. Lett., 66, 3030 (1995)
  •  
  • 11. Yu G, Cao Y, Zhang C, Li Y, Gao J, Heeger AJ, Appl.Phys. Lett., 73, 111 (1998)
  •  
  • 12. Yang RQ, Wu HB, Cao Y, Bazan GC, J. Am. Chem. Soc., 128(45), 14422 (2006)
  •  
  • 13. Ershov M, Liu HC, Li L, Buchanan M, Wasilewski ZR, Jonscher AK, IEEE T. Electron Dev., 45, 2196 (1998)
  •  
  • 14. Bisquert J, Garcia-Belmonte G, Pitarch A, Bolink HJ, Chem. Phys. Lett., 422(1-3), 184 (2006)
  •  
  • 15. Ehrenfreund E, Lungenschmied C, Dennler G, Neugebauer H, Sariciftci NS, Appl. Phys. Lett., 91, 012112 (2007)
  •  
  • 16. Pei QB, Yu G, Zhang C, Yang Y, Heeger AJ, Science, 269(5227), 1086 (1995)
  •  
  • 17. Smith DL, J. Appl. Phys., 81, 2869 (1997)
  •  
  • 18. Hoven C, Yang R, Garcia A, Heeger AJ, Nguyen TQ, Bazan GC, J. Am. Chem. Soc., 129(36), 10976 (2007)
  •  
  • 19. Park J, Yang RQ, Hoven CV, Garcia A, Fischer DA, Nguyen TQ, Bazan GC, DeLongchamp DM, Adv. Mater., 20(13), 2491 (2008)
  •  
  • 20. Park J, Hoven CV, Yang R, Cho N, Wu H, Nguyen TQ, Bazan GC, J. Mater. Chem., 19, 211 (2009)
  •  
  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2024 Impact Factor : 0.6
  • Indexed in SCIE

This Article

  • 2012; 36(4): 519-524

    Published online Jul 25, 2012

  • Received on Jan 18, 2012
  • Accepted on Mar 6, 2012