Enhanced energy storage property and dielectric tunability of Na0.5Bi0.5(Ti,W,Ni)O3 thin film on Bi(Fe,Mn)O3 buffered LaNiO3(100)/Si substrate

Abstract

Na0.5Bi0.5(Ti,W,Ni)O3 (NBTWN) thin films were fabricated on the pure and Bi(Fe,Mn)O3 buffered Pt/TiO2/SiO2/Si and LaNiO3(100)/Si substrates by chemical solution deposition, respectively. The crystallization, surface morphology, and electrical properties of the four films are mainly investigated. The films, which are grown on the Pt/TiO2/SiO2/Si substrates, exhibit similar polycrystalline structure. Whereas for films deposited on the LaNiO3 (100)/Si substrates, strong (l00) orientations are observed. Compared with the NBTWN film on pure Pt/TiO2/SiO2/Si, the introduction of Bi(Fe,Mn)O3 buffer layer and LaNiO3 oxide electrode can promote the grain growth of the NBTWN resulting in larger grain size. Large remanent polarization and breakdown strength can be observed in films with Bi(Fe,Mn)O3 buffer layers. Furthermore, the combination of low leakage current and good energy storage capacity, together with high dielectric tunability is achieved in NBTWN/Bi(Fe,Mn)O3/LaNiO3(100)/Si heterostructure. The enhancement in electrical properties may be attributed to the preferred crystalline orientation and optimized grain size depending on both the buffer layer and the electrode that are used.