Absolute quantum yield measurements of colloidal NaYF4: Er~(3+), Yb~(3+) upconverting nanoparticles

摘要

In this communication we describe a technique for measuring the absolute quantum yields (QYs) of upconverting nanomaterials based on the use of a commercially available fluorimeter and an integrating sphere. Using this setup, we have successfully acquired luminescence efficiency data (pump laser, absorbed pump, and visible emitted intensities) for lanthanide-doped upconverting nanoparticles. QYs in the range of 0.005% to 0.3% were measured for several NaYF4: 2% Er~(3+), 20% Yb~(3+) nanoparticles with particle sizes ranging from 10 to 100 nm while a QY of 3% was measured for a bulk sample.