Ultrasensitive Flexible κ-Phase Ga2O3Solar-Blind Photodetector

Yi Lu, Shibin Krishna, Xiao Tang, Wedyan Babatain, Mohamed Ben Hassine, Che Hao Liao, Na Xiao, Zhiyuan Liu, Xiaohang Li*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


Flexible Ga2O3photodetectors have attracted considerable interest owing to their potential use in the development of implantable, foldable, and wearable optoelectronics. In particular, β-phase Ga2O3has been most widely investigated due to the highest thermodynamic stability. However, high-quality β-phase Ga2O3relies on the ultrahigh crystallization temperature (usually ≥750 °C), beyond the thermal tolerance of most flexible substrates. In this work, we epitaxially grow a high-quality metastable κ-phase Ga2O3(002) thin film on a flexible mica (001) substrate under 680 °C and develop a flexible κ-Ga2O3thin film photodetector with ultrahigh performance. Epitaxial κ-Ga2O3and the mica substrate are maintained to be thermally stable up to 750 °C, suggesting their potential for harsh environment applications. The responsivity, on/off ratio, detectivity, and external quantum efficiency of the fabricated photodetector are 703 A/W, 1.66 × 107, 4.08 × 1014Jones, and 3.49 × 105%, respectively, for 250 nm incident light and a 20 V bias voltage. These values are record-high values reported to date for flexible Ga2O3photodetectors. Furthermore, the flexible photodetector shows robust flexibility for bending radii of 1, 2, and 3 cm. More importantly, it shows strong mechanical stability against 10,000 bending test cycles. These results reveal the significance of high-quality κ-phase Ga2O3grown heteroepitaxially on a flexible mica substrate, especially its potential for use in future flexible solar-blind detection systems.

Original languageEnglish (US)
Pages (from-to)34844-34854
Number of pages11
JournalACS Applied Materials and Interfaces
Issue number30
StatePublished - Aug 3 2022


  • flexible optoelectronic
  • photoresponsivity
  • robust flexibility
  • solar-blind photodetector
  • κ-phase GaO

ASJC Scopus subject areas

  • General Materials Science


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