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NOGUCHI Yutaka
Department Undergraduate School , School of Science and Technology Position Professor |
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| Language | English |
| Publication Date | 2015/06 |
| Type | Academic Journal |
| Peer Review | Peer reviewed |
| Title | Analyzing degradation effects of organic light-emitting diodes via transient optical and electrical measurements |
| Contribution Type | Co-authored (other than first author) |
| Journal | Journal of Applied Physics |
| Journal Type | Another Country |
| Publisher | AIP publishing |
| Volume, Issue, Page | 117(21),pp.215502 |
| International coauthorship | International coauthorship |
| Author and coauthor | Tobias D. Schmidt, Lars Jäger, Yutaka Noguchi, Hisao Ishii, Wolfgang Brütting |
| Details | We present a comprehensive degradation study of an OLED structure comprising the well-known green phosphorescent emitter Ir(ppy)3. We use transient methods to analyze both electrical and optical changes during an accelerated aging protocol. Combining the results of displacement current measurements with time-resolved investigation of the excited states lifetimes of the emitter allows for a correlation of electrical (e.g., increase of the driving voltage due to trap formation) and optical (e.g., decrease of light-output) changes induced by degradation. Therewith, it is possible to identify two mechanisms resulting in the drop of the luminance: a decrease of the radiative quantum efficiency of the emitting system due to triplet-polaron-quenching at trapped charge carriers and a modified charge carrier injection and transport, as well as trap-assisted non-radiative recombination resulting in a deterioration of the charge carrier balance of the device. |
| DOI | http://dx.doi.org/10.1063/1.4921829 |