Direct Quantum Yield Measurements of Unknown Luminescent Samples
Quantum yield is one of the most important parameters that characterize photoluminescence of materials. Photoluminescence Quantum Yield (PLQY) measurements are critical for a broad range of applications, including new material development, photovoltaics and the development of new fluorescence probes. With thousands of PLQY citations around the world, ֱ has long been recognized for its superior quality of PLQY performance for the most demanding applications.
The QuantaPhi-2 is a new internal photoluminescence quantum yield (PLQY) and CIE measurement accessory for compatible ֱ fluorescence spectrometers. Compatible ֱ fluorescence systems include the following:
- Fluorolog-QM modular research spectrofluorometer
- Nanolog modular research spectrofluorometer
- FluoroMax Plus bench top research spectrofluorometer
This sample tray accessory includes an all-reflective sphere into which a sample is placed. The measurement of the sample, and of a non-fluorescent blank, allows for the direct measurement of the quantum yield of a solid, powder or solution sample.
Combined with our highest sensitivity and flexible spectrofluorometers, and their simple-to-use, dedicated QY and colorimetry software, the QuantaPhi-2 provides a high quality, simple and absolute PLQY solution. The quantum yield of a molecule or material is defined as the number of photons emitted as a fraction of the number of photons absorbed. This characteristic property of a fluorophore or fluorescent molecule, is very important for understanding molecular behavior and optimization for many key materials.
Materials and Applications for which PLQY are Important Parameters
- Photovoltaics (PV) and solar cells
- Novel nanomaterials
- Nanoparticles
- Quantum dots
- Graphene/single walled carbon nanotubes
- New fluorescent probes
- Biomarkers and biosensors
- Lighting and display materials (OLED, LED and phosphors)
- Thin films and coatings
- Light emitting devices
- Cured/doped polymers, gels, hydrogels
- Paints, coatings,
- Rare earth materials
Characterize Light-emitting Devices
Electroluminescent quantum yield (ELQY) measurements of light-emitting devices, such as LEDs, OLEDs, and other luminescent sources, are fully accommodated by the QuantaPhi-2. Electrical connections to the device are facilitated by a dedicated wiring port in the bottom loading drawer, allowing a customer to feed wires to their custom modified sample cup holder. Shown below are the CIE values and total luminous intensity plots of a simple LED measured using the QuantaPhi-2.

ֱ FluorEssence software interface for the Fluoromax and Nanolog spectrofluorometers.
Software That Makes PLQY Simple and Accurate
The QuantaPhi-2 integrating sphere accessory is compatible with a number of ֱ fluorescence spectrometers, and all of these systems have a PLQY App, that simplifies the process of acquiring an accurate QY value for an unknown sample.

FelixFL software on the Fluorolog-QM modular research spectrofluorometer incorporates a quantum yield calculator which, when coupled with an integrating sphere, allows you to calculate the quantum yield with ease.