QD Products
1、What is quantum dot?
A quantum dot (QD) is a semiconductor nanocrystal (sometimes referred to as “artificial atom”, “super lattice”, “super atom” or “quantum dots atom”) is small enough to exhibit quantum mechanical properties. Typically, QDs consist of II-VI group elements (such as CdS and CdSe, CdTe and ZnSe) and III-V group elements (such as InP, InAs) with single or core-shell structure with sizes of 1~10 nanometer (nm) in diameter.
Due to its excitons are confined in all three spatial dimensions, the properties of QDs are intermediate between those of bulk semiconductors and of discrete molecules.The application of QDs are expected to attract more and more attention and greatly influence nanometer electronics and optoelectronics, photon and quantum computing and even the life sciences.

2、What is FWHM?
The emission spectra of QDs is a typical Gaussian distribution curve. The full width at half maximum of the emission peak is also called (FWHM), which directly reflects the size distribution of the luminescent core of QDs. Small FWHM indicates narrow size distribution.
3、What is Quantum Yield?
The luminescent quantum yield (ΦF) is the ratio of the number of fluorescence photons emitted to the number of photons absorbed. In other words the quantum yield gives the probability of the excited state being deactivated by fluorescence rather than by another, nonradiative mechanism. 0 ≤ ΦF ≤ 1
4、Whether the size of ligands is included in the hydrodynamic size?
No. The size of ligands is ~1-2nm.
5、How to measure the size of QDs?
By TEM or laser particle size analyzers.
6、Do you provide special customized QDs to your customers?
Yes, we try our best to accommodate our customers’ needs.
7、Do you provide water-soluble QDs in solid states to your customers?
Yes. Upon customer’s request, we also provide water-soluble QDs in solid states, which can be simply dissolved by adding water or buffer.
8、What are the surface ligands of your synthetic oil-soluble QDs in general?
OLAM, OA, and ODA are commonly used as the ligands of oil-soluble QDs. In addition, we also provide samples with customer specified surface groups, solvent, concentration, and emission wavelength.
9、What are the surface groups of your synthetic water-soluble QDs in general?
PEG-COOH, PEG-NH2, and MPA-COOH are commonly used as the ligands of water-soluble QDs. In addition, we also provide samples with customer specified surface groups, solvent, concentration, and emission wavelength.
10、What is the storage condition for QDs?
Store in cool (10-20℃), dry, and dark place in tightly closed containers. Under an inert gas atmosphere (such as Ar) would be better.
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