Rare Earth Nanocrystal NIR Conversion Efficiency

The patent employs a core-shell nanocrystal structure where the core contains multiple rare earth dopants (Yb3+, Tm3+, Nd3+) for efficient NIR absorption and wavelength conversion, while the shell provides protective and functional properties. This composite architecture achieves high conversion efficiency by combining multiple phosphorescent centers in a single nanocrystal, eliminating the need for multiple separate phosphor layers and reducing thermal quenching through the shell barrier.

The patent merges multiple phosphor materials into a single core-shell nanocrystal entity, combining NIR absorption, upconversion, and downconversion functions in one particle. This integration eliminates the need for separate phosphor packaging layers and complex assembly processes, while achieving ideal energy conversion efficiency and thermal management through the nanoscale core-shell design.

The patent uses a thin shell layer in the core-shell nanocrystal structure that provides thermal isolation and protection. This shell acts as a thermal barrier that prevents heat from the high-power operation from reaching the phosphorescent core, thereby preventing thermal quenching, color drive, and efficiency drop while allowing high power operation.

The patent optimizes the dopant concentrations and ratios (Yb3+, Tm3+, Nd3+) within the nanocrystal to maximize conversion efficiency and emission intensity. By precisely controlling these compositional parameters, the phosphor achieves high detection sensitivity for low concentration particles, while the nanocrystal formulation maintains relative manufacturing simplicity through a single-particle synthesis approach.