Anomalous change in dielectric constant of CaCu3Ti4O12 under violet-to-ultraviolet irradiation

C. Masingboon, T. Eknapakul, S. Suwanwong, P. Buaphet, H. Nakajima, S. -K. Mo, P. Thongbai, P. D. C. King, S. Maensiri, W. Meevasana*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)
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The influence of light illumination on the dielectric constant of CaCu3Ti4O12 (CCTO) polycrystals is studied in this work. When exposed to 405-nm laser light, a reversible enhancement in the room temperature capacitance as high as 22% was observed, suggesting application of light-sensitive capacitance devices. To uncover the microscopic mechanisms mediating this change, we performed electronic structure measurements, using photoemission spectroscopy, and measured the electrical conductivity of the CCTO samples under different conditions of light exposure and oxygen partial pressure. Together, these results suggest that the large capacitance enhancement is driven by oxygen vacancies induced by the irradiation.

Original languageEnglish
Article number202903
Number of pages5
JournalApplied Physics Letters
Issue number20
Publication statusPublished - 20 May 2013


  • Copper-titanate
  • SRTIO3
  • Capacitance
  • Dielectric constant
  • Vacancies
  • Photoemission


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