多孔硅负载银纳米颗粒提高硅基MSM光电探测器性能的研究

Porous silicon distributed by silver nanoparticles for performance enhancement of silicon-based MSM photodetectors

利用金属辅助刻蚀的方法在单晶硅片表面制备了多孔硅,结果表明多孔硅表面纳米结构的陷光作用在宽光谱范围内大幅提高了硅片的光吸收率。将银纳米颗粒负载到多孔硅表面,研究了其对硅基金属-半导体-金属型光电探测器(MSM-PDs)性能的影响。与基于硅片和多孔硅结构的MSM-PDs相比,基于多孔硅负载银纳米颗粒制备的MSM-PDs在420 nm入射光照射条件下的光暗电导比以及光响应度都有显著提高,这主要得益于表面纳米结构对暗电导的降低及光场中银纳米颗粒的LSPR效应对光电导的提升作用。

Porous silicon （PS） was prepared by metal-assistedly etching the single crystal silicon surface. Light absorbance in the prepared PS is significantly increased in a broad spectral range due to light trapping effect by the surface nanostructures. Effects of Ag nanoparticles on the performance of porous silicon based metal-semiconductor-metal photodetectors （MSM-PDs） were investigated. It is found that both the ratio of photo current to dark current and the responsivity of MSM-PD prepared from Ag dispersed porous silicon （APS） are effectively enhanced under irradiation at the wavelength of 420 nm, as compared with those of MSM-PDs prepared from silicon and porous silicon. Performance enhancement of APS based MSM-PD can be attributed to reduction in dark current caused by surface nanostructures and enhancement of photo current resulted from LSPR effects of silver nanoparticles in the light field.