Presentation Information
[10p-PB1-10]Effects of bismuth incorporation site and oxidation state of bismuth oxide on
threshold voltage and current non-linearity of thin-film Bi-doped ZnO varistors
〇Efi Dwi Indari1, Shinjiro Yagyu1, Naoki Ohashi1, Takahiro Nagata1 (1.NIMS)
Keywords:
zinc oxide,varistor,defect
We employed an RF sputtering combinatorial method to evaluate the correlations between crystallinity, defects induced, and the electrical properties of gradually Bi-doped (0-10%) ZnO thin film varistors (Bi-ZnO). The thin film depositions were conducted on Pt/Si substrates at several substrate temperatures and oxygen partial pressures (OPPs). The Bi-ZnO was characterized using two-dimensional XRD, XPS, and I-V measurements. We found that OPP affected the retention of the ZnO (0002) polycrystalline structure, bismuth incorporation sites, and bismuth oxide oxidation states upon doping. These factors strongly affected the current non-linearity and threshold voltage of Bi-ZnO. In addition, OPP led to trap state formation at different energy levels, shifted the Fermi energy, and thus modified the I-V characteristics.