Microstructural, chemical and electrical characteristics of Au/magnetite (Fe3O4)/n-GaN MIS junction with a magnetite interlayer

Magnetite (Fe3O4) layers were prepared on n-type GaN surface by the e-beam method and its microstructural and compositional characteristics were evaluated by XRD, XPS and TEM techniques. The XRD, XPS and TEM evaluations confirmed the formation of the Fe3O4 layer on the n-GaN surface. Then, the Au/Fe3O4/n-GaN metal/interlayer/semiconductor (MIS) junction was fabricated and its electrical properties investigated with the I-V and C-V approaches. The MIS junction showed a good rectification nature with a high barrier height (0.83 eV) compared to the SE (0.71 eV). This implies that the barrier height was markedly affected by the Fe3O4 layer. Further, the barrier height was extracted by means of Cheung's, Norde and psi(s)-V plot and it was found that the values are nearly matched with one another, indicating that the methods used were consistent and valid. The frequency-dependent properties of the MIS and SE junctions have also been discussed. The interface state density (N-ss) of the MIS junction was found to be lower than the SE, indicating that the Fe3O4 layer plays a vital role in the decreased N-ss. Based on the analysis, it can be concluded that the Fe3O4 layer is an apt material for the fabrication of new electronic device applications.