Quantum Dots

Quantum dots are synthesized nanoparticles that have many promising applications in medicine, photovoltaics, and LED’s. Determining the size distribution of quantum dots is important in helping determine synthesis routes.

The Fluorolog-QM fluorescence spectrometer with an integrating sphere option is an excellent choice for PLQY measurements in NIR. The K-Sphere is very convenient and easy to use, as it couples directly to the sample compartment optics and allows a use of external light sources, such as DPSS lasers, which can be attached to the front of the sample compartment. The sphere has holders for cuvettes, slides and powders that can be easily interchanged. The results demonstrate very good reproducibility and precision for NIR PLQY measurements spanning almost two orders of magnitude. Based on multiple measurements, the demonstrated PLQY standard deviations range from 1.3% for high QY value (77%) to 6.4% for the QY below 1%.

The new Fluorolog-QM spectrofluorometers, due to their modularity and advanced software and a universal interface, are an ideal choice for studying multiple aspects of upconversion. This technical note illustrates the use of Fluorolog-QM-75-21 for spectral and time-resolved characterization of these materials.

InGaAs/GaAs and InAs/GaAs quantum dots (QDs) have been identified as suitable candidates for various applications in the terahertz range by using their intraband carrier transitions.

This technical note serves as a guideline to selecting the best solid state detector with the Fluorolog-QM modular research spectrofluorometer for a given series of photoluminescence experiments.

During the last two decades, a great deal of attention has been focused on the optoelectronic properties of nanostructured semiconductors or Quantum Dots (QDs).

Quantum dots (QDs) are semiconducting spheres in the size typically in the range of 1 to 10nm. The size of these small spheres give quantum dots the semiconducting properties and resulting photoluminescence that would not necessarily occur for the same material on larger scales.

Quantum dots (QDs) have potential applications in optoelectronics, biosensing, biolabeling, memory devices, and sources of laser light.