Migration-based energy storage and luminescence

Does energy migration facilitate energy transport over a long distance?

Unlike energy transfer, energy migration is able to facilitate energy transport over a long distance (Fig. 1b) 20. The manipulation of energy migration among Yb sublattice can produce color-switchable emissions 20, 21, 22, 23 and tunable lifetimes across a wide range 24, 25.

Why is energy migration important?

Energy migration is an essential process in numerous systems, such as natural photosynthetic proteins, artificial polymers, and inorganic optical materials 1, 2, 3.

Does energy migration occur simultaneously with energy transfer in a sensitizer-activator system?

We show that energy migration indeed occurs simultaneously with energy transfer in a sensitizer-activator system and the competition between them can be quantified by proposing a characteristic ratio parameter. Moreover, this model is also able to realize the color-switchable photochromic upconversion by temporal control of up-transition processes.

Does topological arrangement enhance upconversion luminescence?

Here, we report an inorganic optical nanosystem composed of NaErF 4 and NaYbF 4, in which topological arrangement enhanced upconversion luminescence. Three architectures are designed for considerations pertaining to energy migration and energy transfer within nanoparticles: outside-in, inside-out, and local energy transfer.

Which structure produces maximum upconversion luminescence?

The outside-in architecture produces the maximum upconversion luminescence, around 6-times brighter than that of the inside-out at the single-particle level. Monte Carlo simulation suggests a topology-dependent energy migration favoring the upconversion luminescence of outside-in structure.

Which energy transfer pathways were added in the simulation?

The energy transfer pathways from sensitizer (Yb 3+) to activator (Er 3+) in the interlayer were added in the simulation, leading to high non-radiative and radiative recombination rates from Er 3+ and a decline of upconverted emission from Tm 3+ in the core region. The details are provided in the Supplementary Information.