Investigation of Ga2 O3-based deep ultraviolet photodetectors using plasma-enhanced atomic layer deposition system

Shao Yu Chu, Meng Xian Shen, Tsung Han Yeh, Chia Hsun Chen, Ching Ting Lee, Hsin Ying Lee

Research output: Contribution to journalLetterpeer-review

Abstract

In this work, Ga2 O3 films were deposited on sapphire substrates using a plasma-enhanced atomic layer deposition system with trimethylgallium precursor and oxygen (O2) plasma. To improve the quality of Ga2 O3 films, they were annealed in an O2 ambient furnace system for 15 min at 700, 800, and 900 C, respectively. The performance improvement was verified from the measurement results of X-ray diffraction, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The optical bandgap energy of the Ga2 O3 films decreased with an increase of annealing temperatures. Metal-semiconductor-metal ultraviolet C photodetectors (MSM UVC-PDs) with various Ga2 O3 active layers were fabricated and studied in this work. The cut-off wavelength of the MSM UVC-PDs with the Ga2 O3 active layers annealed at 800 C was 250 nm. Compared with the performance of the MSM UVC-PDs with the as-grown Ga2 O3 active layers, the MSM UVC-PDs with the 800 C-annealed Ga2 O3 active layers under a bias voltage of 5 V exhibited better performances including photoresponsivity of 22.19 A/W, UV/visible rejection ratio of 5.98 × 104, and detectivity of 8.74 × 1012 cmHz1/2 W−1 .

Original languageEnglish
Article number6159
Pages (from-to)1-10
Number of pages10
JournalSensors (Switzerland)
Volume20
Issue number21
DOIs
Publication statusPublished - 2020 Nov 1

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Biochemistry
  • Atomic and Molecular Physics, and Optics
  • Instrumentation
  • Electrical and Electronic Engineering

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