Microstructure and the boson peak in thermally treated ${\mathrm{In}}_{x}\mathrm{O}$ films

Microstructure and the boson peak in thermally treated ${In}_{x} O$ films

Itai Zbeda, Ilana Bar, and Z. Ovadyahu

Phys. Rev. Materials 5, 085602 – Published 26 August 2021

Abstract

We report on the correlation between the boson peak and the structural changes associated with thermally treating amorphous indium-oxide films. In this process, the resistance of a given sample may decrease by a considerable margin whereas its amorphous structure is preserved. In the present paper, we focus on the changes that result from the heat treatment by employing electron-microscopy, x-ray, and Raman spectroscopy. These techniques were used on films with different stoichiometry and, thus, different carrier concentrations. The main effect of heat treatment is material densification, which presumably results from elimination of microvoids. The densified system presents better wave-function overlap and more efficient connectivity for the current flow. X-ray and electron-beam diffraction experiments indicate that the heat-treated samples show significantly less spatial heterogeneity with only a moderate change in the radial-distribution function metrics. These results are consistent with the changes that occur in the boson-peak characteristics due to annealing as observed in their Raman spectra.

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Received 18 March 2021
Accepted 6 August 2021

DOI:https://doi.org/10.1103/PhysRevMaterials.5.085602

Physics Subject Headings (PhySH)

Structural properties

Disordered systems Semiconductor compounds Thin films

Raman spectroscopy X-ray diffraction

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Itai Zbeda ¹, Ilana Bar ¹, and Z. Ovadyahu ²

¹Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
²Racah Institute of Physics, The Hebrew University, Jerusalem 9190401, Israel