Effect of Lattice Defect on Luminescence Intensity of 808 nm Responsive Core-Shell Upconversion Nanomaterials

Abstract

Lanthanide-doped inorganic nanocrystals are able conversion of NIR light to visible or even to ultraviolet through the upconversion process. In recent times, NIR-upconverting crystalline nanoparticles have been used extensively in clinical applications. 980 nm laser sources absorbed extensively by water present in animal tissue. Although a type of 808 nm-responsive core-shell-based UCNP has been proposed to overcome the above problem, such nanoparticles lack the diversity and intensity of the upconverted UV-visible emission required to perform any effective biological application. Herein, the proposed plan, a pathway for developing 808 nm-responsive core-shell UCNP through Nd3+-sensitization with an intense emission profile is described. In the beginning, the reason and challenges for developing such a particular type of UCNP is discussed. Subsequently, a rational methodology to fabricate core-shell-based UCNP with a well-thought-out crystal engineering approach will be discussed also. Apart from synthesizing the UCNP with an enhanced emission profile by incorporating non-lanthanide doping of Li+ in the core nominally, a thorough characterization of the crystalline structure and photoluminescence study is proposed. The detailed mechanism behind the intensification of the emission profile is to perturbation of crystal field symmetry of crystal lattice to be investigated by lattice strain analysis, phase purity was also confirmed by Rietveld refinement by using high energy Synchrotron X-ray radiation.