Scalable hot carrier–assisted silicon photodetector array based on ultrathin gold film

Geunpil Kim, Hyebi Kim, Young Uk Jeon, In Soo Kim, Soo Jin Kim, Sangsik Kim, Jongbum Kim

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Silicon (Si) offers cost-effective production and convenient on-chip integration for photodetection due to its well-established CMOS technology. However, the indirect bandgap of Si inherently limits its detection efficiency in the near-infrared (NIR) regime. Here, we propose a strategy to achieve high NIR photoresponse in Si by introducing a strong light-absorbing ultrathin gold (Au) film to generate hot carriers. Using a 4.6 nm thick-Au film deposited on Si, we achieved photoresponsivity of 1.6 mA/W at 1310 nm under zero-bias conditions, and rapid temporal responses of 7.5 and 8 μs for rise and fall times, respectively, comparable to germanium (Ge) photodiodes. By utilizing an ultrathin (<6 nm) Au film as the light-detecting layer and thicker (>100 nm) Au film as electrodes, we introduce a unique approach to design a photodiode array based on a single metal (Au) platform. Comparative analysis with a commercial beam profiler image validates the performance of our designed array. This work presents an efficient strategy for manufacturing cost-effective and scalable NIR photodetector arrays, which eliminates the need for additional insulator layers.

Original languageEnglish
Pages (from-to)1049-1057
Number of pages9
Issue number7
Publication statusPublished - 2024 Mar 3

Bibliographical note

Publisher Copyright:
© 2023 the author(s), published by De Gruyter.


  • NIR photodetection
  • extinction coefficient
  • gold film
  • hot carrier
  • photodetector array

ASJC Scopus subject areas

  • Biotechnology
  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering


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