Based on a developed theory, we show that introducing a meta-grid of sub-wavelength-sized plasmonic nanoparticles (NPs) into existing semiconductor light-emitting-devices (LEDs) can lead to enhanced transmission of light across the LED-chip/encapsulant interface. This results from destructive interference between light reflected from the chip/encapsulant interface and light reflected by the NP meta-grid, which conspicuously increase the efficiency of light extraction from LEDs. The “meta-grid”, should be inserted on top of a conventional LED chip within its usual encapsulating packaging. As described by the theory, the nanoparticle composition, size, interparticle spacing, and distance from the LED-chip surface can be tailored to facilitate maximal transmission of light emitted from the chip into its encapsulating layer by reducing the Fresnel loss. The analysis shows that transmission across a typical LED-chip/encapsulant interface at the peak emission wavelength can be boosted up to ~99%, which is otherwise mere ~84% at normal incidence. The scheme could provide improved transmission within the photon escape cone over the entire emission spectrum of an LED. This would benefit energy saving, in addition to increasing the lifetime of LEDs by reducing heating. Potentially, the scheme will be easy to implement and adopt into existing semiconductor-device technologies, and it can be used separately or in conjunction with other methods for mitigating the critical angle loss in LEDs.

基于已发展的理论，我们表明，将亚波长尺寸的等离子体纳米粒子 (NP) 的元网格引入现有的半导体发光器件 (LED) 可以增强 LED 芯片/密封剂的光传输界面。这是由芯片/密封剂界面反射的光与 NP 元网格反射的光之间的相消干涉造成的，这显着提高了 LED 的光提取效率。“元网格”应插入常规 LED 芯片顶部的常规封装内。正如该理论所描述的，纳米颗粒的成分、尺寸、颗粒间距和距 LED 芯片表面的距离可以进行定制，以通过减少菲涅耳损耗，促进从芯片发出的光最大程度地传输到其封装层中。分析表明，峰值发射波长下典型 LED 芯片/密封剂界面的透射率可提高至约 99%，而在法向入射时仅为约 84%。该方案可以在 LED 的整个发射光谱上改善光子逃逸锥内的传输。除了通过减少热量来延长 LED 的使用寿命之外，这还有利于节能。该方案可能很容易实施并采用现有的半导体器件技术，并且可以单独使用或与其他方法结合使用，以减轻 LED 的临界角损耗。