【International Papers】Structure-property correlation of europium doped β-Ga₂O₃: an experimental and first-principle study

      Researchers from the School of Mechanical Engineering, KIIT Deemed to be University of India have published a dissertation titled " Structure-property correlation of europium doped β-Ga₂O₃: an experimental and first-principle study " in Journal of Materials Science: Materials in Electronics.

Abstract

      In this work, the structure-properties correlation of Eu-doped β-gallium oxides was studied by both experimental as well as first-principle studies. The thin films were grown by the PVD co-sputtering method on a quartz substrate and analyzed further. The results showed that thin film fabricated were nanocrystalline structures with an average grain size of ∼ 0.029 ± 0.005 μm, and preferably oriented towards the (-201) plane. The band gap energy (Eg) of intrinsic β-Ga₂O₃ measured from the Tauc plot shows a decreasing trend, as the band energy gap decreases from 3.98 to 3.88 eV on Eu doping, while the optical transmittance doesn’t show any effect. Further, a first-principal study was conducted, and the simulated result of the band structure of β-Ga₂O₃ on Eu doping also follows the same decreasing trend as the experimental results. The electronic band structure of intrinsic β-Ga₂O₃ reduces to 3.41 eV from 4.9 eV on Eu doping. The total and partial density of states (DOS) results suggested that the reason behind the decreasing trend of the band structure of β-Ga₂O₃ may be due to the dominance of the 4f states orbital in the lower conduction band on Eu doping in the tetrahedral site. The reflectance and energy loss function shows a reduction due to Eu doping, although the transmittance and absorption edge remains unaffected. There was a redshift in the absorption spectra observed of intrinsic β-Ga₂O₃ on Eu doping, which improves the visible light absorption. It is suggested that co-doping with other rare earth metals may be able to tune the Eg and make it useful for monolithic and phosphor-free LEDs applications.

Paper Link：https://doi.org/10.1007/s10854-023-11455-x