[20a-B204-1~11] 6.3 Oxide electronics

△ [20a-B204-8] Hydrogen gas sensing using oxide semiconductor films (3)
Gas sensing by Al: ZnO films loaded with Pt or Pd nanoparticles

〇Masayuki Endo¹, Hiroki Sone¹, Makoto Kashiwagi¹, Junjun Jia², Yuki Oguchi¹, Akira Nakamura³, Yuzo Shigesato¹ (1.AGU, 2.Waseda Univ., 3.MinebeaMitsumi Inc.)

Keywords:H2 gas sensing

As the thin film H₂ gas sensors, Al-doped ZnO (AZO) films loaded with Pt or Pd nano-particles were fabricated by sputtering. The AZO films were deposited on glass substrates heated at 300℃ by rf magnetron sputtering. Pt or Pd were deposited by dc magnetron sputtering on the unheated AZO films. For the Pt or Pd depositions, a three-dimensional growth mode (the Volmer-Weber-type) is expected. The surface coverages of Pt or Pd were analyzed quantitatively by X-ray photoelectron spectroscopy, where the atomic ratios of Pt/(Pt+Zn) or Pd/(Pd+Zn) were estimated using the integrated peak areas and atomic sensitive factors of Pt(4d), Pd(3d) and Zn(2p3/2). The surface coverage of Pt or Pd on the AZO films gradually increased with the increasing their deposition time. The coverage was about 50% at the deposition time of 5 or 9 sec for Pt or Pd, respectively. In the operation temperature range of 200-350℃, the gas sensitivity to H₂ gas was remarkably improved by loading Pt or Pd. The activation energies of gas sensing determined from the Arrhenius plot will be discussed in detail.