机构地区:[1]School of Energy and Power Engineering,Nanjing University of Science and Technology
出 处:《Chinese Science Bulletin》2013年第6期696-700,共5页
基 金:This work was supported by the National Natural Science Foundation of China(50936002).
摘 要:Microstructured metallic gratings can be used to enhance the light emission efficiency of LEDs,and the spectral radiation properties of the LEDs vary with the different metallic materials used,leading to variation of the light emission enhancement at the same wavelength for different metallic grating materials.In this paper,the finite difference time domain(FDTD) method has been used to investigate the light emission extraction enhancement of LEDs in which gratings with different metallic materials have been applied.Through analysis of the permittivity of the metals and the quality factors of the surface plasmons(SPs),we concluded that the larger the plasma frequency obtained for the metallic interband transition,then the more suitable the metals are for light emission extraction of photons with relatively short wavelengths.This is because of the abundance of free electrons in the metals with large plasma frequencies.We also found that the wavelength-dependent trends of the extraction enhancement resulting from the scattering mechanism for different metallic materials are similar to each other.For SP-induced enhancement,either the enhancement peak position or the peak value changes significantly with the different metals.Microstructured metallic gratings can be used to enhance the light emission efficiency of LEDs, and the spectral radiation proper- ties of the LEDs vary with the different metallic materials used, leading to variation of the light emission enhancement at the same wavelength for different metallic grating materials. In this paper, the finite difference time domain (FDTD) method has been used to investigate the light emission extraction enhancement of LEDs in which gratings with different metallic materials have been applied. Through analysis of the permittivity of the metals and the quality factors of the surface plasmons (SPs), we concluded that the larger the plasma frequency obtained for the metallic interband transition, then the more suitable the metals are for light emission extraction of photons with relatively short wavelengths. This is because of the abundance of free electrons in the metals with large plasma frequencies. We also found that the wavelength-dependent trends of the extraction enhancement resulting from the scattering mechanism for different metallic materials are similar to each other. For SP-induced enhancement, either the en- hancement peak position or the peak value changes significantly with the different metals.
关 键 词:金属光栅 发光效率 微结构 提取 应用 等离子体频率 金属材料 时域有限差分
分 类 号:TN312.8[电子电信—物理电子学]
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