A hybrid treatment of Ba2LaV3O11:Eu3+ nanophosphor system: First-principal and experimental investigations into electronic, crystal and the optical structure

Abstract

A systematic computational analysis is integrated with the experimental records like Rietveld and Judd-Ofelt studies to have a deeper insight into the structural and optoelectronic characteristics of Eu3+-doped Ba2LaV3O11 system. The vanadates used were developed via solution combustion-synthesis (SCS) route, with all ab-initio calculations performed in the density functional framework. The Rietveld refinement over Ba2La0.65Eu0.35V3O11 lattice confirmed the phase purity and crystal structure prototype (monoclinic with P21/a space group). The first-principal routed structure-optimization of the pure host unveiled not only the total energy but also the atomic positions which were unknown till date. The experimental band-gap (3.724 eV) was found to be pretty much comparable to the value obtained computationally (3.482 eV). The partial density of states (PDOS) were analyzed orbital-as well as element-wise to understand the electronic structure in a more comprehensive manner. The calculation of dielectric function yielded the value of many important optical properties like refractive index, extinction-coefficient, optical-conductivity, and loss-function. The photoluminescent (PL) excitation-emission and decay analysis revealed a very efficient energy transfer from vanadate absorption of Ba2LaV3O11 to Eu3+; resulting in a significantly intense emission with blue-white-red color tunability. Furthermore, the density-functional assisted PL analysis also provided the Judd-Ofelt parameters (Ω2 = 3.3175 × 10−20 cm2 and Ω4 = 0.1197 × 10−20 cm2), radiative-lifetime (2.03 ms), emission cross-sections (10.80 × 10−22 cm2), quantum efficiencies and radiative rates for 5D0 term. All optoelectronic results of Ba2La0.65Eu0.35V3O11 phosphor suggest that it can be used in the nanocrystalline form for white light emitting diodes (WLEDs) while potentially the bulk crystal in laser devices. Moreover, the results of this report may find applications in designing novel material based upon Ba2LaV3O11 lattice.