In this paper, we use FDTD Solutions software to construct the light-absorption model of InGaAs/InP thin films modified by Au nanoparticles. And the effects of Au nanoparticles on the light-absorption performance of thin films in the near-infrared wavelengths are investigated in terms of nanoparticle position, array period, and particle radius. And for the 1064 nm wavelength band, we obtain the optimal structural model. It has been shown that nanoparticle modification on the front side of the emission layer is the most effective in promoting light absorption; the resonance peaks formed by the surface plasmon excitations can greatly affect the light-absorption rate of Au nanoparticles adsorbed on the film, and the position of the absorption peaks can be changed by altering the array period and particle radius to achieve the enhancement of the film's absorption of light in a specific wavelength band. For the 1064 nm band, we obtain the best model, when the radius of Au NPs in the emission layer is 25 nm, and the model absorption with an array period of 150 nm is up to 84.85%, and the quantum efficiency is improved by one-third compared with the thin film. It provides a certain reference for the design of photocathode in the near-infrared band.

在本文中，我们使用FDTD Solutions软件构建了Au纳米粒子修饰的InGaAs/InP薄膜的光吸收模型。并从纳米粒子位置、阵列周期和粒子半径等方面研究了Au纳米粒子对近红外波长薄膜光吸收性能的影响。对于1064 nm波段，我们得到了最优的结构模型。研究表明，发射层正面的纳米粒子修饰对于促进光吸收最有效；表面等离子体激元激发形成的共振峰可以极大地影响薄膜上吸附的Au纳米粒子的光吸收率，并且可以通过改变阵列周期和粒子半径来改变吸收峰的位置，从而实现薄膜光吸收的增强。特定波长范围内的光的吸收。对于1064 nm波段，我们得到了最好的模型，当发射层Au NPs的半径为25 nm时，阵列周期为150 nm的模型吸收高达84.85%，量子效率提高了与薄膜相比，减少了三分之一。为近红外波段光电阴极的设计提供了一定的参考。