Capacitive β-Ga2O3solar-blind photodetector with graphene electrode

Ayeong Kim, Geonyeop Lee, Jihyun Kim

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Conventional solar-blind photodetectors based on the conduction of photoexcited carriers are energy inefficient owing to the power dissipation caused by a resistive sensing mechanism and the narrow bandgap energy of the photon-absorbing layer. Herein, we demonstrate the energy-efficient capacitive sensing of deep-UV wavelengths by integrating an intrinsically solar-blind ultrawide bandgap (UWBG) β-Ga2O3 semiconductor with UV-transparent and conductive graphene electrode. A UWBG β-Ga2O3 eliminates the requirement of a solar-blind deep-UV bandpass filter. The high optical transmittance of the graphene enables UV-C light to be absorbed in the underlying β-Ga2O3, thereby facilitating carrier transport between the graphene electrode and β-Ga2O3. A capacitance change under UV-C excitation is observed, along with excellent reproductivity and spectral selectivity at various frequencies and bias conditions; the sensing performance improves with an increase in frequency. The average power dissipation of the fabricated photodetector in the stand-by (dark) and active (UV-C illumination) modes is 37.7 and 53.3 μW, respectively. Overall, this work introduces a new strategy for developing next-generation compact and energy-efficient solar-blind photodetectors.

Original languageEnglish
Article number053412
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Issue number5
Publication statusPublished - 2021 Sept 1

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation (NRF) of Korea funded by the Ministry of Science and ICT (Nos. 2018R1D1A1A09083917 and 2020M3H4A3081799) and the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration and Ministry of Trade, Industry, and Energy of Korea.

Publisher Copyright:
© 2021 Author(s).

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films


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