Tailoring The Luminescence Intensity of 808 NM Responsive Core-Shell Upconversion Nanomaterials by The Introduction of Non-Lanthanide Ion Li

Abstract

Lanthanide-doped Upconversion nanoparticles are able to tune NIR light to visible or even to ultraviolet. In recent times, 980 nm-responsive NIR-upconverting crystalline nanoparticles have been used extensively in biological applications. However, due to the strong water absorption profile of 980 nm excitation, the concerned upconverting nanoparticle (UCNP) suffers from heating effect and poorer tissue penetration. 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. In the proposed plan, a pathway for developing 808 nm-responsive core-shell UCNP with an intense and diversified emission profile is described. In the beginning, the reason and challenges for developing such a particular type of UCNPs is discussed. Subsequently, a rational methodology to fabricate core-shell based UCNP with 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