Microestructura y propiedades eléctricas de bismuto y oxido de bismuto depositados por magnetrón sputtering UBM

Abstract

In this work, bismuth (Bi) and bismuth oxide (Bi$_2$O$_3$) thin films were prepared, at room temperature, by Sputtering Unbalanced Magnetron (UBM - Unbalance Magnetron) technique under glass substrates. Microstructural and electrical properties of the samples were studied by X-ray diffraction (XRD ) and System for Measuring Physical Properties - PPMS (Physical Property Measurement System). Dark resistivity of the material was measured for a temperature range between 100 and 400 K. From the XRD measurements it was observed a polycrystalline character of the Bi associated to the presence of phases above the main peak, 2$\theta$ = 26.42$^{\circ}$ and a growth governed by a rhombohedral structure. Crystal parameters were obtained for both compounds, Bi and Bi$_2$O$_3$. From the analysis of the spectra of the conductivity as a function of temperature, it was established that the transport mechanism that governs the region of high temperature (T$> $300 K ) is thermally activated carriers. From conductivity measurements the activation energies were obtained of 0.0094 eV and 0.015 eV for Bi$_2$O$_3$ and Bi, respectively.