• 文献标题:   High-Performance Graphene Nanowalls/Si Self-Powered Photodetectors with HfO2 as an Interfacial Layer
  • 文献类型:   Article
  • 作  者:   SHEN YH, LI YL, CHEN WC, JIANG SJ, LI C, CHENG QJ
  • 作者关键词:   hafnium oxide, graphene nanowall, plasmaenhanced chemical vapor deposition, photodetector
  • 出版物名称:   NANOMATERIALS
  • ISSN:  
  • 通讯作者地址:  
  • 被引频次:   0
  • DOI:   10.3390/nano13101681
  • 出版年:   2023

▎ 摘  要

Graphene/silicon (Si) heterojunction photodetectors are widely studied in detecting of optical signals from near-infrared to visible light. However, the performance of graphene/Si photodetectors is limited by defects created in the growth process and surface recombination at the interface. Herein, a remote plasma-enhanced chemical vapor deposition is introduced to directly grow graphene nanowalls (GNWs) at a low power of 300 W, which can effectively improve the growth rate and reduce defects. Moreover, hafnium oxide (HfO2) with thicknesses ranging from 1 to 5 nm grown by atomic layer deposition has been employed as an interfacial layer for the GNWs/Si heterojunction photodetector. It is shown that the high-k dielectric layer of HfO2 acts as an electron-blocking and hole transport layer, which minimizes the recombination and reduces the dark current. At an optimized thickness of 3 nm HfO2, a low dark current of 3.85 x 10(-10), with a responsivity of 0.19 AW(-1), a specific detectivity of 1.38 x 10(12) as well as an external quantum efficiency of 47.1% at zero bias, can be obtained for the fabricated GNWs/HfO2/Si photodetector. This work demonstrates a universal strategy to fabricate high-performance graphene/Si photodetectors.