Multi-variable compensated quantum yield measurements of upconverting nanoparticles with high dynamic range: a...

Area of Science:

• Nanotechnology
• Materials Science
• Photonics

Background:

• Upconverting nanoparticles (UCNPs) are advanced non-linear materials with diverse applications.
• Characterizing UCNP quantum yield (QY) is difficult due to power density dependence and distorting factors.
• Existing commercial QY systems struggle with the dynamic range and specific challenges of UCNPs.

Purpose of the Study:

• To develop and validate a multimodal system for accurate UCNP quantum yield (QY) measurement.
• To address the challenges of power density dependence and distorting parameters in UCNP characterization.
• To enable high-resolution QY measurements over a wide dynamic range.

Main Methods:

• A multimodal system was designed to measure QY across a 1:10^4 dynamic range.
• Beam shaping techniques were employed to create speckle-free beam profiles (530 µm or 106 µm).
• The system compensates for scattering, beam profile, inner filter effect, and emission bandwidth.

Main Results:

• The system achieved high-resolution quantum yield (QY) curves with low noise.
• A signal-to-noise ratio exceeding 50 was obtained at low power densities.
• A Tm-based core-shell UCNP was successfully investigated, demonstrating system capability.

Conclusions:

• The proposed multimodal system offers a robust solution for UCNP quantum yield (QY) characterization.
• Accurate QY measurement is crucial for optimizing UCNP applications.
• This technology advances the reliable assessment of non-linear optical materials.