A self-powered high-performance graphene/silicon ultraviolet photodetector with ultra-shallow junction: breaking the limit of silicon?

By X. Wan, Yang Xu, Hongwei Guo, Khurram Shehzad, Ayaz Ali, Yuan Liu, Jianyi Yang, Daoxin Dai, Cheng‐Te Lin, Liwei Liu and 15 more. npj 2D Materials and Applications, 2017

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We present a self-powered, high-performance graphene-enhanced ultraviolet silicon Schottky photodetector. Different from traditional transparent electrodes, such as indium tin oxides or ultra-thin metals, the unique ultraviolet absorption property of graphene leads to long carrier life time of hot electrons that can contribute to the photocurrent or potential carrier-multiplication. Our proposed structure boosts the internal quantum efficiency over 100%, approaching the upper-limit of silicon-based ultraviolet photodetector. In the near-ultraviolet and mid-ultraviolet spectral region, the proposed ultraviolet photodetector exhibits high performance at zero-biasing (self-powered) mode, including high photo-responsivity (0.2 A W−1), fast time response (5 ns), high specific detectivity (1.6 × 1013 Jones), and internal quantum efficiency greater than 100%. Further, the photo-responsivity is larger than 0.14 A W−1 in wavelength range from 200 to 400 nm, comparable to that of state-of-the-art Si, GaN, SiC Schottky photodetectors. The photodetectors exhibit stable operations in the ambient condition even 2 years after fabrication, showing great potential in practical applications, such as wearable devices, communication, and “dissipation-less” remote sensor networks.Optoelectronics: Graphene breaks limit of silicon-based UV detectionA high-performance graphene/silicon ultraviolet (UV) photodetector significantly increases the upper-limit of traditional silicon-based UV detectors. A team led by Yang Xu at China’s Zhejiang University fabricated silicon-based UV detectors using graphene with unique UV absorption property, leading to ultra-long lifetime of hot carriers that contribute to photocurrent, and even to carrier multiplication. In the near- and mid-UV regime, the improved performance parameters are photocurrent responsivity (0.20 A W−1), response time (<5 ns), specific detectivity (1.6 × 1013 Jones), and IQE (>100%). The key metrics of graphene/Si detector outperform those of UV detectors based on Si, GaN, SiC, etc. These results show great promise in applications such as wearable devices, secured mobile communication, and “dissipation-less” remote sensor networks.

Subfields: Biomedical Engineering, Electronic, Optical and Magnetic Materials, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/ba380c3c938e8b0b27f33579363245f6f829c2ef