Structural properties and dopant-modified bandgap energies of Ba0.5 Sr 0.5 TiO 3 thin films grown on LaAlO 3 substrates

Abstract

Ba 0.5 Sr 0.5 TiO 3 thin films doped with different concentration of Ti, Mg and Al dopants were prepared by pulsed laser deposition technique on LaAlO 3 substrates. The crystalline properties of these doped thin films were studied using X-ray diffraction, micro-Raman scattering, atomic force microscopy, and transmission electron microscopy. The bandgap energies of BST thin films are determined from the transmission and absorption measurements by the ultraviolet-visible spectrophotometer. It was found out that the bandgap energies of the doped BST thin films depend strongly on the dopant concentration.

Properties of TiO2/LaxTi1-xOy/TiO2Stacked Thin Films

“…1,2) On the other hand, TiO 2 and BST have high dielectric constants but have narrow band gaps. [3][4][5][6] Since La 2 O 3 is highly absorbent and La(OH) 3 is formed in moisture, which deteriorates the dielectric constant and leakage current characteristics, 7,8) a mixed film of La x Ti 1Àx O y (LTO) is investigated to eliminate absorbency. In this study, stacked structures of LTO and TiO 2 are investigated to increase the dielectric constant while maintaining conduction band offset and suppressing leakage current.…”

Temperature dependence of broadband near-infrared luminescence from Ni2+-doped Ba0.5Sr0.5TiO3

“…It is known that LAO can be widely utilized as substrate to fabricate dielectric and ferroelectric thin films. 23 BST thin film is highly oriented grown on (100) LAO substrate. Figure 5(b) presents the NIR PL spectrum of Ni 2þdoped BST(1200 nm)/LAO sample at room temperature, under 350 nm excitation.…”