Luminescence and dielectric properties of Ni2+ ions added to calcio yttria borophosphate glasses for optoelectronic uses

Abstract

Glass materials of composition CaO–Y2O3–B2O3–P2O5 added with different concentrations of NiO (Ni2+:CYBP) are synthesized by conventional rapid melt quenching method. Various physical properties of these glasses such as polaron radius (rp), molar volume (Vm), optical basicity (Λth) and refractive index (μ) are studied. As an elastic characterization Young's modulus (Y), Poison ratio (σ) and micro hardness (H) of these glasses are studied. These grades suggest that the prepared materials are mechanically hard and exhibiting covalently interlinked structure. Further these samples are characterized by various techniques such as differential thermal analysis, thermoluminiscence, optical absorption, photoluminescence, Ionic conductivity and dielectric dispersion. The thermoluminiscence grades such as peak temperature maximum (Tm), shape symmetry factor (μsf) and activation energies (Eτ, Eδ and Eω) are studied at various UV irradiation levels. These results strongly recommended that the both electron and hole trap centers were created at the deeper trap levels and contribute higher orders of thermoluminiscence emission with in these glasses subjected to higher orders of temperature and UV irradiation. The various optical absorption and photoluminescence factor's such as, optical band gap (Eo), nephelauxetic ratio (β), emission cross section (Ω), branching ratio (ξ) and radiative life times (τ) are studied. These grades found to be maximum for the material which has 0.5 mol% of NiO concentration may be most suggestible for optoelectronic application. The dc and ac conductivity (σdc & σac) of these glasses are estimated. The various dielectric parameter's such as loss tangent (Tan (ϕ)), temperature region of relaxation (ΔT), density of states near Fermi level (N(Ef)), activation energies of both dipoles and conduction (Ed and Ec) are also calculated. These reports clearly disclose that the octahedrally located Ni2+ ions are increasing with increase NiO concentration with in present calcio yttria borophosphate glasses.