Photoluminescence of Barium Titanate and Barium Zirconate in Multilayer Disordered Thin Films at Room temperature

Abstract

The emission of wide band photoluminescence showed a synergic effect on barium zirconate and barium titanate thin films in alternate multilayer system at room temperature by 488 nm exiting wavelength. The thin films obtained by spin-coating were annealed at 350, 450, and 550 degrees C for 2 h. The X-ray patterns revealed the complete separation among the BaTiO3 and BaZrO3 phases in the adjacent films. Visible and intense photoluminescence was governed by BaZrO3 thin films in the multilayer system. Quantum mechanics calculations were used in order to simulate ordered and disordered thin films structures. The disordered models, which were built by using the displacement of formers and modifier networks, showed a different symmetry in each system, which is in accordance with experimental photoluminescence emission, thus allowing to establish a correlation among the structural and optical properties of these multilayered systems.

A theoretical study on the photoluminescence of SrTiO3

“…Based on both experimental (such as most recent X-ray absorption studies EXAFS and XANES) of STO as well as theoretical calculations performed by our group, we have now reached a consensus that room temperature PL emission in perovskite based materials originates mainly from their structural disorder at short-range [6,[28][29][30]. Such structural disorder will result in a non-uniform band-gap structure in which electrons or holes may be trapped [29,31,32].…”

Synthesis and characterization of new phosphor based MTiO3

“…These values show good agreement with reference value of BaTiO 3 . BaTiO 3 has a tetragonal crystal system with a = 399.4 pm, c = 403.3 pm; V= 643x10 5 pm 3 [8]. Heat treatment at 1000 o C was applied to CaTiO 3 and CaTiO 3 : Eu 3+ (1% mol), Dy 3+ (1% mol) were applied before SEM analyses were performed.…”

“…Several titanates are also known to be promising host matrices. The PL investigations of barium titanate have been extensively discussed by Moreira et al [8]. In addition, the PL of several other titanate systems such as gadolinium titanate, zirconium titanate, strontium titanate, lead titanate and calcium titanate, and magnesium titanate are available in the literature [9][10][11][12].…”

Photoluminescence in Low-Dimensional Oxide Ferroelectric Materials

“…The remarkable room temperature PL effects observed are contributed to both metastable and energetically stabilized defect states formed inside the band gap. Moreira, et al [76] studied photoluminescence of barium titanate and barium zirconate in multilayer disordered thin films at room temperature. The thin films were prepared by spincoating and annealed at 350, 450, and 550 o C for 2 h. It was observed that the wide band emission showed a synergic effect on barium zirconate and barium titanate thin layers in alternate multilayer system at room temperature by 488 nm excitation.…”