Quantum dot light enhancement substrate and lighting device including same
摘要
說(shuō)明書
OLED technology has been widely viewed as having great potential for SSL. Until recently, these devices utilized fluorescent emitter species which, due to their intrinsic, unmodified limitations, could theoretically emit at 5% external efficiency. This is due to the fact that fluorescent small molecule materials can create photons out of only 25% of the electricity they consume, and that in an unmodified device only ?20% of the generated photons escapes wave-guiding. The development of Phosphorescent OLEDs (Ph-OLEDs), first introduced by Prof. Marc Baldo, which can theoretically harvest 100% of consumed energy, has increased this efficiency potential substantially with recent devices exhibiting 40 lm/W with an EQE of 20% (unmodified by further out-coupling enhancements) (N. Ide et al., “Organic Light Emitting Diode (OLED) and its application to lighting devices,” SPIE Proceedings, 6333, 63330M (2005)). Similarly, advances in optical out-coupling have improved extraction efficiencies by up to 85% (Y.-C. Kim, S.-H. Cho, Y. W. Song, Y.-J. Lee, Y.-H. Lee, Y. R. Do, Appl. Phys. Lett. 2006, 89, 173502).
In certain embodiments, waveguide-mode dynamics are included with a film or layer comprising quantum dots to provide a low-complexity, low cost, and more effective means of out-coupling blue light (e.g., blue light emitted from a Ph-OLED light) while using QD technology to tune this emission into high CRI light. This can be accomplished by using a high index of refraction (n) QD film between the ITO and the substrate, effectively coupling the light specifically and predominantly into the film via its favorable location and n, as shown in
