| AVS 54th International Symposium | |
| Thin Film | Tuesday Sessions |
| Session TF-TuP |
| Session: | Aspects of Thin Films Poster Session |
| Presenter: | J.T. Lim, Sungkyunkwan University, Korea |
| Authors: | G.Y. Yeom, Sungkyunkwan University, Korea J.T. Lim, Sungkyunkwan University, Korea |
| Correspondent: | Click to Email |
The top-emitting organic light-emitting diodes (TEOLEDs) have generated considerable interest in recent years, owing to their use in active matrix displays. Significant progress has been made in the development of thin semitransparent conducting cathodes (STCCs), semi-transparent conducting cathode (STCC) thin film composed of Ba (x nm)/Ag (10 nm)/ITO (100 nm) (x: 0,, 1, 2 and 3 nm) were fabricated by thermal evaporation. The optical properties of STCCs at the wavelength of 535 nm showed the transmittance of about 77 % and the reflectance of about 13 %, respectively. The TEOLED which is consisted of glass/Ag (100 nm)/tin-doped indium oxide (125 nm)/4,4’,4”-tris[2-naphthylphenyl-1- phenylamino]triphenylamine (2-TNATA, 30 nm)/ 4,4’-bis[N-(1-napthyl)-N-phenyl- amino]-biphenyl (NPB, 15 nm)/tris(8-quinolinolato) aluminum (III) (Alq3, 55 nm)/Ba (x nm)/Ag (20 nm)/ITO (100 nm) showed the highest driving performance when the deposition thickness of Ba is 1 nm. The effect reducing the barrier height for an electron-injection from Ba to Alq3 can explain a driving performance of these devices. We proved these results by measuring a built-in potential in the devices. Meanwhile, in the case of the top-emitting device with the Ba (1 nm)/Ag (20 nm)/ITO (100 nm) cathode, the maximum luminance was about 80,000 cd/m2 and an external quantum efficiency at about 100 cd/m2 was 1.5 %.