| 학회 | 한국고분자학회 |
| 학술대회 | 2004년 가을 (10/08 ~ 10/09, 경북대학교) |
| 권호 | 29권 2호, p.111 |
| 발표분야 | 분자전자 부문위원회 |
| 제목 | Current status of hole injection materials for PLED |
| 초록 | Polymer light-emitting diodes(PLEDs) have been the subject of intense research interests recently due to their applications in large-area flat panel displays. To achieve highly efficient PLED devices, charge (holes and electrons) injection and transport from both the anode and the cathode should be balanced at the junction of the emitting layer to yield the maximum exciton formation. In a multilayer PLED, it is highly desirable to develop a suitable hole-injection layer(HIL) that combines good mechanical properties and thermal and electrochemical stability. Metallic polymers such as polyaniline(PANI) in the emeraldine salt form and doped poly(ethylenedioxythiophene)(PEDOT) were introduced as bilayer electrodes for PLED with the idea of improving injection. Although the high conductivity of the metallic polymers was an initial motivation for their use in bilayer anodes, the high conductivity resulted in undesirable crosstalk between pixels in pixilated displays. As a result, low conductivity formulations of these polymers with (for example) polystyrene sulfonate(PSS) as polyanion [PANI:PSS and PEDOT:PSS] were developed and optimized for performance and lifetime. It has been shown, however, that PEDOT:PSS is not stable in the PLED architecture. Due to the strong acidic nature of PSS, the aqueous solution from which the PEDOT:PSS film cast can also be expected to etch the ITO. Since low-conductivity HILs are desirable, other materials should be seriously considered as alternatives. The principal criteria are the following: (1) The HIL must form a high quality film that is not soluble in the solvent used for the semiconducting polymer. (2) The highest occupied molecular orbital (HOMO) of the injection layer must be at an energy close to, or even below, that of the p-band of the semiconducting polymer. In this talk, the issues of hole injection materials, various anode modification and new hole injection materials for PLED will be discussed. |
| 저자 | 황진택, 임보규, 강석주, 박두진, 김동유 |
| 소속 | 광주과학기술원 |
| 키워드 | PLED; Hole injection material |
