近年来,表面等离激元(SP)增强的金属纳米结构中热载流子产生、传输和收集得到了广泛而深入的研究。其中,利用电子隧穿和热发射效应实现的全新光电转换机制,结合平面化制作和CMOS兼容集成等,有望成为硅基红外光电探测的备选方案。目前这类探测器主要为金属-半导体肖特基结的光伏型器件,其光电响应较弱。为此,报道了一种基于金属-硅复合无序纳米结构的光电导器件,得益于无序表面等离激元局域热点效应和多叉指金属-半导体-金属(MSM)结构的显著光电导增益,实验获得了硅亚带隙的宽带强光电响应。该热载流子介导的多叉指MSM器件在1310 nm波长处的光电流响应度高达2.50 A/W。

In recent years, the generation, transport, and harvesting of hot carriers in surface plasmon (SP) enhanced metal nanostructures have been extensively and deeply studied. Among them, a new photoelectric conversion mechanism based on electronic tunneling and thermal emission effect, combined with planarization manufacture and complementary metal oxide semiconductor (CMOS) compatible integration, is expected to be an alternative scheme for silicon-based infrared photoelectric detection. At present, these detectors are mainly used in metal-semiconductor Schottky junction photovoltaic devices, which have weak photoelectric response. In this paper, a novel photoconductive device based on metal-silicon composite disordered nanostructures is reported. Due to the localized hot spot effect of the disordered surface plasmon and the significant photoconductivity gain of the multiple interdigital metal semiconductor metal (MSM) structures, the broad-band strong photoelectric response of the silicon sub-band gap is obtained experimentally. Finally, the photocurrent responsivity of the hot carrier mediated multiple interdigital MSM devices is as high as 2.50 A/W at 1310 nm.