Monoclinic Zirconium Oxide Nanostructures Having Tunable Band Gap Synthesized under Extremely Non-Equilibrium Plasma Conditions

Abstract

Zirconium oxide (ZrO2) is a wide and direct band gap semiconductor used for the fabrication of optoelectronic devices. ZrO2 based optoelectronic devices span a wide optical range depending on the band gap of ZrO2 material. The band gap of ZrO2 can be tuned by fabricating it to the nanoscale. In this paper, we synthesized the ZrO2 nanostructures on quartz substrate using ZrO2 ions produced by the ablation of ZrO2 pellet due to high temperature, high density, and extremely non-equilibrium argon plasma in a modified dense plasma focus device. Uniformly distributed monoclinic ZrO2 nanostructures with an average dimension of ~14 nm were obtained through X-ray diffraction and scanning electron microscopy studies. The monoclinic phase of ZrO2 nanostructures is further confirmed from photoluminescence (PL) and Raman spectra. PL spectra show peaks in ultra-violet (UV), near-UV, and visible regions with tunable band gap of nanostructures. A similar tunability of band gap was observed from absorption spectra. The obtained structural, morphological, and optical properties are compared to investigate the potential applications of ZrO2 nanostructures in optoelectronic devices.