https://scholars.lib.ntu.edu.tw/handle/123456789/333795
標題: | Efficient white OLEDs employing phosphorescent sensitization | 作者: | C.-H. Chang Y.-J. Lu Z.-Z. Liu CHUNG-CHIH WU |
關鍵字: | Phosphorescent sensitization; Solid-state lighting; White organic light-emitting devices (WOLEDs) | 公開日期: | 六月-2007 | 卷: | 3 | 期: | 2 | 起(迄)頁: | 193-199 | 來源出版物: | IEEE Journal of Selected Topics in Quantum Electronics/Journal of Display Technology | 摘要: | We have investigated white-emitting organic light-emitting devices (WOLEDs) making use of both blue-phosphorsensitized orange-red fluorescence and the residual blue phosphorescence. By carefully adjusting the concentrations the phosphor and the fluorophore in the emitting layer and choosing the carrier-transport layers in the device structure, WOLEDs containing a single phosphor-sensitized emitting layer (type-I devices) can give colors close to the equal-energy white (0.33,0.33), CRI up to 75, and efficiencies up to (10%, 23 cd/A, 13.4 lm/W). Furthermore, by doping a green phosphor into the poorly emitting electron-transport layer (type-II devices) to recycle excitons formed there, the EL efficiencies can be further enhanced up to (12.1%, 35.3 cd/A, 23.9 lm/W). In both types of devices, the phosphor sensitization reduces population of triplet excitons in the emitting region and substantially mitigates the efficiency roll-off with the driving current or brightness that is often observed in all-phosphor OLEDs. At the brightness of 1000 cd/m2, both types of devices retain quantum and cadmium per ampere (cd/A) efficiencies similar to their peak values. © 2007 IEEE. |
URI: | http://scholars.lib.ntu.edu.tw/handle/123456789/333795 https://www.scopus.com/inward/record.uri?eid=2-s2.0-34249277089&doi=10.1109%2fJDT.2007.895354&partnerID=40&md5=7c0b4977723e2d1952b169fa9e6ec832 |
DOI: | 10.1109/JDT.2007.895354 | SDG/關鍵字: | Carrier transport; Concentration (process); Fluorophores; Light emission; Phosphorescence; Phosphors; Semiconductor doping; Carrier transport layers; Phosphorescent sensitization; Solid state lighting; Organic light emitting diodes (OLED) |
顯示於: | 電機工程學系 |
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