This paper presents modeling results of Mie-type GaAs nanopillar array resonant structures and the design of negative electron affinity photocathodes based on Spicer's three-step model. For direct-bandgap GaAs with high intrinsic absorption coefficient in the 500 ∼ 850 nm spectral range, photoelectrons were found to be highly localized inside the nanopillars near the top and side surfaces where electrons can be efficiently transported and emitted into vacuum, and the light reflectance can be reduced to ∼1% level at resonance wavelengths. Predictions of spectrally resolved photoemission indicate that these nanophotonics resonators, when properly optimized, can increase the photo-electron emission quantum efficiency at resonance wavelengths to levels limited only by the surface-electron escape probability, significantly outperforming traditional flat wafer photocathodes. Ultrafast photoelectric response is also expected from these nanostructured photocathodes due to the much shorter photoelectron transport distance in nanopillars compared to flat wafers. Given these unique optoelectronic properties, GaAs nanophotonic resonance structured photocathodes represent a very promising alternative to photocathodes with flat surfaces that are widely used in many applications today.

中文翻译：

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用于负电子亲和力阴极的Mie型GaAs纳米柱阵列谐振器。

本文介绍了Mie型GaAs纳米柱阵列共振结构的建模结果以及基于Spicer的三步模型设计的负电子亲和性光电阴极的设计。对于在500〜850 nm光谱范围内具有高本征吸收系数的直接带隙GaAs，发现光电子高度集中在纳米柱内部，靠近顶面和侧面，可以有效地传输电子并将其发射到真空中，并且光反射率高。在共振波长下可以降低到〜1％的水平。光谱分辨光发射的预测表明，如果适当优化，这些纳米光子共振器可以将共振波长处的光电子发射量子效率提高到仅受表面电子逸出概率限制的水平，大大优于传统的平面晶圆光电阴极。这些纳米结构的光电阴极也有望实现超快的光电响应，这是因为与平板晶圆相比，纳米柱中的光电子传输距离要短得多。鉴于这些独特的光电特性，GaAs纳米光子共振结构的光电阴极代表了如今已广泛用于许多领域的具有平坦表面的光电阴极的非常有希望的替代品。