Controlling Energy Distribution in Multilayer Nanostructures for Bioimaging and Photoelectric Conversion.

In recent years, Er3+-based luminescent nanomaterials have attracted significant attention, particularly due to their red and NIR-II emissions, which hold great potential for applications in biomedical imaging and new energy technologies. However, constructing efficient energy transfer pathways to enhance their emission intensity remains a challenge. This work presents a novel Er3+-based luminescent nanomaterial. By designing a passivated core and outer shell, energy is largely confined within the activated shells. Furthermore, through the construction of a Yb3+ sublattice shell and the introduction of Yb3+ and Tm3+ into the core, the material leverages Yb3+ energy migration, Yb3+-to-Er3+ energy back-transfer, and the role of Tm3+ as an energy-trapping center. Consequently, highly efficient Er3+ red and NIR-II emissions are achieved. Subsequently, biological experiments were conducted, applying this nanomaterial for red and NIR-II imaging in live mice, yielding favorable three-dimensional imaging results. Additionally, by establishing a photoelectric detection platform, the nanomaterial demonstrated promising photoelectric conversion performance. This work provides insights for exploring the applications of Er3+-based luminescent nanomaterials in bioimaging and solar cells.