Capacitive β-Ga2O3solar-blind photodetector with graphene electrode

Ayeong Kim, Geonyeop Lee, Jihyun Kim

Research output: Contribution to journalArticlepeer-review

Abstract

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
Volume39
Issue number5
DOIs
Publication statusPublished - 2021 Sep 1

ASJC Scopus subject areas

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

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