基于石墨烯/硅微米孔阵列异质结的高性能近红外光探测器

本文报道了一种由石墨烯和硅微米孔阵列构筑的异质结探测器，具备高性能近红外光探测能力。通过光刻和反应离子刻蚀技术制备的硅微米孔阵列具有整齐光滑的表面，保证了较低的表面载流子复合速率。同时，孔阵列结构能有效地抑制入射光的反射，增加了有效光照面积，提高了石墨烯/硅异质结的吸收效率，从而提高了器件的光响应度。器件在±3 V偏压下表现出明显的电流整流特性，整流比为4.30×105，在功率密度为4.25 mW/cm2的810 nm入射光照射下器件的开关比达到了9.20×105。在入射光强为118.00 μW/cm2的810 nm光照下，光探测器的电流响应度可达到679.70 mA/W，探测率为3.40×1012 Jones；入射光强为7.00 μW/cm2电压响应度为1.79×106 V/W。更重要的是，该器件具有20.00/21.30 μs的升/降响应速度。相比于商业化硅光电二极管，石墨烯/硅微米孔阵列光电探测器结构简单、制备工艺简便，有望大幅降低制备成本。研究结果显示了石墨烯/硅微米孔阵列异质结探测器在未来低成本、稳定和高效近红外光探测应用方面的巨大潜力。

High-Performance Near-Infrared Photodetector Based on a Graphene/Silicon Microholes Array Heterojunction

This paper reports a heterojunction photodetector constructed from a graphene and silicon microhole array that possesses high-performance near-infrared light detection capabilities. The silicon microhole array constructed by photolithography and reactive ion etching has a smooth surface, which ensures a low surface carrier recombination rate. Meanwhile, the hole-array structure can effectively suppress the reflection of incident light, increase the effective illumination area, and improve the photoabsorption efficiency of the graphene/silicon heterojunction, thereby improving the responsivity of the device. The device exhibits evident current rectification characteristics under a ±3 V bias, with a rectification ratio of 4.30 ×105, and a current on-off ratio of 9.20×105 under irradiation with 810 nm incident light with a power density of 4.25 mW/cm2. Under the illumination of 810 nm with the power intensity of 118 μW/cm2, the current responsivity of the photodetector can reach 679.70 mA/W, and the specific detectivity is 3.40×1012 Jones. The voltage responsivity reaches 1.79×106 V/W at an incident power intensity of 7 μW/cm2. More importantly, the device exhibited a swift response speed with rise/decay times of 20/21.3 μs. Compared with commercial Si-based photodiodes, the graphene/silicon microhole array photodetector has features, including a simple device geometry and simplified fabrication processes, that may significantly reduce the fabrication cost. The results demonstrate the substantial potential of graphene/silicon microhole array heterojunction photodetectors for low-cost, stable, and efficient near-infrared light detection applications in the future.