Enhanced structural and electrical properties of lead-free y-doped (K, Na) NbO3 thin films

Abstract

Yttrium- doped KNN thin films were grown on Si substrates using the sol-gel technique. The profound effects of Yttrium with different content element (mol % = 0, 0.1, 0.3, 0.5, 0.7 and 0.9) on the structural and electrical properties of KNN films were analyzed. The doped samples demonstrated a mainly uniform and homogenous microstructure with grain size less than 100 nm. The existence of Y Ka line shown in EDX spectrum confirmed the presence of Y-dopant in KNN based-compound. Small shift position of the Raman peaks indicated that Y incorporated on the interstitial A-site while broaden FWHM ascribed that Y preferably enters B-site lattice at high dopant concentration. The enhanced electrical resistivity at 0.5 mol % Y suggested that more conduction electrons were formed in KNN lattice structure.