Structural and DC conduction studies on vacuum evaporated BaTiO3 thin films prepared from BaTiO3 nano particles synthesised by wet chemical method

Abstract

BaTiO3 nanoparticles prepared by wet chemical method were thermally grown onto well cleaned glass substrates under the vacuum of 2×10−5Torr, using 12A4 Hind Hivac coating unit. An Al–BaTiO3–Al sandwich structure has been used for electrical conduction properties in the temperature range 303–423K. The composition of nanoparticles and thin films were identified by EDS spectrum. The structural studies have been performed by the X-ray diffraction (XRD) technique. The X-ray analysis showed that the nano particle has a tetragonal structure and deposited films at a lower thickness amorphous in nature, whereas the crystallinity increases with increase of thickness. In the DC conduction studies, the current–voltage characteristics of the films showed ohmic conduction in the low voltage region. In the higher voltage region, a space charge limited conduction (SCLC) takes place due to the presence of the trapping level. The activation energy was estimated and the values found to decrease with increasing applied voltage. The zero field value of the activation energy is found to be 0.31eV. The free carrier mobility, carrier density and trap density values were calculated and reported in this paper.