Advancements in multicolor control of lanthanide-doped upconversion nanoparticles for red/green/blue luminescence

Abstract

Lanthanide-doped upconversion nanoparticles (UCNPs) are increasingly enabling multicolor emission control for cutting-edge applications in bioimaging and high-resolution displays. This review presents a comprehensive exploration of the strategies employed to modulate emission colors. We begin by dissecting fundamental energy transfer mechanisms highlighting their role in defining color control. Structural engineering, compositional approaches, and modulation techniques are examined for their impact on multicolor control. Special focus is placed on recent advances in orthogonal core/multi-shell architectures that enable red-green-blue emission under distinct near-infrared wavelengths via controlling energy migration pathways and temporal modulations. By consolidating recent progress and addressing ongoing challenges, this review outlines the excitation-selective color tuning in UCNPs for next-generation luminescent materials.