Highly red luminescent Nb2O5:Eu3+ nanoparticles in silicate host for solid-state lighting and energy conversion

Abstract A high intrinsic quantum yield and color purity red-emitting nanostructured Eu3+-doped 1-xSiO2-xNb2O5 materials were prepared by a new sol-gel route at different Si:Nb molar ratio for solid-state lighting and energy conversion. It was evaluated how the composition and annealing temperature can affect the structure of the materials and their luminescence features. Eu3+ ions distribution into the different symmetry sites of nanoscaled orthorhombic or monoclinic Nb2O5 particles considerately influenced their emission profile and efficiency. A UV and blue to red downshifting were detected, and by using Judd-Ofelt theory, high quantum intrinsic quantum yield up to 65% is calculated for the Eu3+ doped Nb2O5 nanoparticles upon excitation at 463 nm. Additionally, the chromaticity diagram figured out a red color purity up to 90.1% is obtained, making them promising material for solid-state lighting. The particle size and doping control make them possible to explore the solid-state property of nanoscaled Nb2O5 particles as a host, with the advantage of their homogenous dispersion in a silicate network, opening the possibility of their use as planar waveguides for solar cell concentrators and energy conversion for enhancement of solar cell efficiency.