Md. Shamim Ahsan, Md. Arif Istiaq Arafat, Tasmima Akter, I. Sohn, Hun-Kook Choi
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引用次数: 0
Abstract
We demonstrate the enhancement of light extraction efficiency of surface-emitting white Organic Light Emitting Diodes (OLEDs) by incorporating micro/nano-metric structures on the outer surface of the 3-layer substrate (SiO2-Si3N4-SiO2). To enhance light extraction efficiency of the OLEDs, various light scattering structures including plano-convex & plano-concave micro-lens array, flat-top & round-top nano-pillars array, and wavy structures were engraved on the outer surface of the substrate layer. For optimization, we varied the thickness of the internal layers of the OLEDs, and height, width, period, and radius of the micro/nano-scale structures. The performance of the micro/nano-structured OLEDs was simulated and analyzed using Lumerical FDTD and GPVDM simulators. We examined the far field light intensity, transmitted power, angular distribution of light, photon escape probability, photon density, internal & external quantum efficiency, and current-voltage curve of the designed OLEDs. We investigated the results in different locations, especially after the substrate layer: Far Field-1 (0 μm), and Far Field-2 (2.5 μm). Compared to conventional OLEDs, the micro/nano-structured OLEDs showed higher external quantum efficiency. The highest external quantum efficiency of 67.304% (Far Field-1) was detected in the round-top nano-pillars array engraved white OLED having structure period of 1.2 μm. We strongly believe that, the proposed micro/nano-structured white OLEDs are suitable for lighting applications.
期刊介绍:
Defect and Diffusion Forum (formerly Part A of ''''Diffusion and Defect Data'''') is designed for publication of up-to-date scientific research and applied aspects in the area of formation and dissemination of defects in solid materials, including the phenomena of diffusion. In addition to the traditional topic of mass diffusion, the journal is open to papers from the area of heat transfer in solids, liquids and gases, materials and substances. All papers are peer-reviewed and edited. Members of Editorial Boards and Associate Editors are invited to submit papers for publication in “Defect and Diffusion Forum” . Authors retain the right to publish an extended and significantly updated version in another periodical.