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Environmentally Friendly Quantum Dots with >75% Quantum Yield

Copper Indium Disulfide/Zinc Sulfide QDs have Great Color-Emitting Properties

The industrial applications for quantum dots (QDs) in liquid-crystal displays continue to grow.  CdSe and related alloys of II-VI semiconductor QDs are of interest within academics due to their narrow band-edge emission derived from their properties as direct semiconductors.[1]  However, the high toxicity of cadmium QDs has driven the focus of research toward non-toxic QDs with similar or improved properties.

Previously, many researchers did not believe that I-III-VI group QD semiconductors could emit pure colors and that it would be impossible for these nanoparticles to ever emit pure colors.[2-6]   Quantum Dot start-up, UbiQD, has set out to prove this theory false.  UbiQD has patented a new technology that allows manufacturing of quantum dots composed of safe and low-cost semiconductors, specifically a core I-III-VI material coated with II–VI semiconductors.[7]

copper

Fig. 1 CuInS2/ZnS QDs with corresponding product numbers and a variety of peak emission levels

 

One of the most promising in this group of quaternary compounds is core/shell structured Copper Indium DiSulfide/Zinc Sulfide QDs.  Strem offers these products, in collaboration with UbiQD, sporting a variety of peak emissions with greater than 75% quantum yields. (Figure 1)

CuInS2/ZnS QDs are free of toxic and environmentally unfriendly heavy metals (e.g. Cd, Pb) and phosphines using a safe and scalable non-injection procedure.  Possessing low self-absorption due to a large Stokes shift observed at greater than 300 meV, these bright photoluminescent compounds are tunable from 550 to 950 nm and stable at elevated temperatures in the presence of air and moisture,  facilitating easy formation of composite materials.

Unlike to the conventional QD solutions, UbiQD products are available in a dry powder able to form evenly dispersed suspensions in non-polar solvents (e.g., toluene, chloroform).  Typical concentrations used fall between ~5 and 200 mg/mL in most applications. The dots have been purified by dissolution followed by precipitation three times to afford the dried powder.  We recommend that these products are best if used within 12 months of receipt.

References:

  1. Nat. Mater., 2013, 12, 445
  2. NPG Asia Materials, 2018, 10, 713.
  3. J. Am. Chem. Soc., 2007, 129, 12388.
  4. J. Am. Chem. Soc., 2008, 130, 9240.
  5. J. Appl. Phys., 2009, 105, 073106.
  6. J. Phys. Chem. Lett., 2014, 5, 336.
  7. US Patent No. US9748422, 2017.

 

Products mentioned in this blog and related literature:

29-8500: Copper Indium Disulfide/Zinc Sulfide Quantum Dots, Peak Emission 550nm ± 10nm, QY > 75%  [927198-36-5]

29-8510: Copper Indium Disulfide/Zinc Sulfide Quantum Dots, Peak Emission 590nm ± 10nm, QY > 75%  [927198-36-5]

29-8520: Copper Indium Disulfide/Zinc Sulfide Quantum Dots, Peak Emission 630nm ± 10nm, QY > 75%  [927198-36-5]

29-8530: Copper Indium Disulfide/Zinc Sulfide Quantum Dots, Peak Emission 680nm ± 10nm, QY > 75%  [927198-36-5]

29-8540: Copper Indium Disulfide/Zinc Sulfide Quantum Dots, Peak Emission 800nm ± 10nm, QY > 75%  [927198-36-5]

29-8550: Copper Indium Disulfide/Zinc Sulfide Quantum Dots, Peak Emission 950nm ± 10nm, QY > 75%  [927198-36-5]

Copper Indium Disulfide/ Zinc Sulfide Quantum Dots Literature Sheet

 

 

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