Effect of varying oxygen partial pressure on the properties of reactively evaporated zinc aluminate thin films

Abstract

Abstract Thin films of zinc aluminate are prepared by reactive evaporation. The composition of these films is varied by changing the oxygen partial pressure and by post-deposition annealing. It is observed that there is wide variation in the band gap values (2.34 – 4.54 eV) depending on the oxygen partial pressure. Further, there is a strong dependence of band gap values on the post-deposition annealing conditions. One of the films exhibits spinel (AB2O4) structure, whereas the rest are amorphous. A resistivity value of as low as 3.6 × 10– 3 ohm-cm has been measured. The compositional studies, using mass spectrometry, reported in this paper point towards novel transparent conducting oxides.