전면 유기발광 다이오드 제작시 Mg:Ag 캐소드 최적화 및 LiF 전자주입층 유무에 따른 소자 특성에 관한 연구

Abstract

For the process simplification in the fabrication of organic light emitting diode(OLED), top emission OLED(TEOLED) was fabricated without lithium fluoride(LiF) used as an electron injection layer (EIL). After co-deposition of Mg and Ag with a different process conditions, a cathode material adjacent to EIL was optimized when Mg and Ag have a ratio of 1:9 considering sheet resistance and transmittance. From the energy band diagram of TEOLED, band gap difference between Trisaluminium (Alq3) and Mg:Ag cathode show the difference of 0.4 eV according to the usage of LiF The fabricated TEOLED without LiF showed the improvement of 5.2 % and 2.7 % in the luminance and the current density comparing that with LiF. The results show there is no significant difference in OLED characteristics regardless of LIF layer in the TEOLED structures.