Electroluminescence of organic light-emitting diodes with an ultra-thin layer of dopant
Li, W; Yu, J; Wang, Tao; Jiang, Y; Wei, B
| HERO ID | 3576500 |
|---|---|
| In Press | No |
| Year | 2008 |
| Title | Electroluminescence of organic light-emitting diodes with an ultra-thin layer of dopant |
| Authors | Li, W; Yu, J; Wang, Tao; Jiang, Y; Wei, B |
| Journal | Materials Science and Engineering B |
| Volume | 149 |
| Issue | 1 |
| Page Numbers | 77-81 |
| Abstract | Conventional fluorescent dyes, i.e., 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), 5,12-dihydro-5,12-dimethylquino [2,3-b]acridine-7,14-dione (DMQA) and 5,6,11,12-tetraphenylnaphthacene (Rubrene), were used to investigate the performance of organic light-emitting diodes (OLEDs) based on indium tin oxide (ITO)/N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB)/tris-(8-hydroxyquinolate)-aluminum(Alq(3))/MgAg. The dyes were either inserted into devices as an ultra-thin film at the NPB/Alq(3) interface by sequential evaporation, or doped into the Alq3 emission layer by co-evaporation with the doping ratio about 2%. Electroluminescence (EL) spectra of devices indicated that concentration quenching effect (CQE) of the dye-dopant was slightly bigger in the former than in the latter, while the degrees of CQE for three dopants are in the order of DMQA > DCJTB > Rubrene suggested by the difference in EL spectra and performances of devices. In addition, EL process of device with an ultra-thin layer of dopant is dominated by direct carrier trapping (DCT) process due to almost no holes recombine with electrons in Alq(3)-host layer. (C) 2007 Elsevier B.V. All rights reserved. |
| Doi | 10.1016/j.mseb.2007.11.027 |
| Wosid | WOS:000256342400013 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Keyword | organic light-emitting diodes; dopant; concentration quenching effect; direct carrier trapping |