- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
European Microscopy Congress 2016: Proceedings || Indexation of diffraction patterns for overlapping crystals in TEM thin foils - Application to orientation mappings
摘要： Application of diffraction gratings for overcoming limitations in organic light-emitting diodes (OLEDs) for displays. The study focuses on enhancing light extraction efficiency and managing color shifts in OLEDs using a novel grating design. The experimental approach involves fabricating and characterizing grating structures on OLED substrates, with results showing significant improvements in efficiency and color stability compared to conventional methods.
关键词： diffraction gratings,color shift,efficiency,OLEDs,light extraction
更新于2025-09-19 17:15:36
-
Red-shift effect in multi-color LEDs based visible light communication
摘要： Visible light communication (VLC) is a short range wireless optical communication system that provides lighting and data transmission, simultaneously. Besides lighting, in order to obtain high data rates, color-shift keying (CSK) which modulates the intensity of light using multi-color light emitting diodes (LEDs) has been introduced in IEEE 802.15.7 VLC standard. In CSK-based VLC (VLC-CSK) systems, some parameters of LEDs such as junction temperature is affected by physical and operation conditions. Junction temperature variations change the power spectral density (PSD) of LEDs, which is known as red-shift effect. In this study, the red-shift effect is examined for the first-time in VLC-CSK systems. The obtained numerical results show that the red-shift effect may dramatically reduce the performance of optical communication system. To eliminate the negative effect of red-shift, an effective solution based on the power normalization is proposed at the receiver side.
关键词： Visible light communication (VLC),red-shift effect,color shift keying (CSK),light-emitting diode (LED)
更新于2025-09-19 17:13:59
-
Suppression of viewing angle dependence of TEOLED devices with internal nano-wrinkle structure
摘要： In order to suppress the viewing angle dependence of top emission organic emitting diodes (TEOLEDs) with strong microcavity effect, we introduced randomly distributed nano-wrinkle structure beneath highly reflective anode. By applying such nano-wrinkle pattern, viewing angle dependence and color shift could be improved compared with that without nano-structure [e.g. Δ(u’, v’): 0.077 → 0.025]. However, current efficiency reduced more than half. To compensate this problem, we additionally introduced index matching epoxy filler between encapsulation glass and TEOLED device. By this approach, current efficiency drop of device with nano-wrinkle structure could be improved. For example, the efficiency dropped by 7.7% when we filled the epoxy filler between capping layer and glass lid while, it decreased by 30.8% if we don’t use epoxy filler. We found that index matching helps to extract more light confined inside TEOLED, so device performance degradation could be minimized. In addition, when we attached a circular polarizer film to these devices, depolarization was observed in most cases, but we were able to achieve a perfect black state from the devices with nano-wrinkle structure underneath reflective anode.
关键词： Black tint,Viewing angle dependence,Index matching,Nano structure,TEOLED,Color shift
更新于2025-09-11 14:15:04