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**[http://www.sciencelab.com/msds.php?msdsId=9927329 ZnO]
**[http://www.sciencelab.com/msds.php?msdsId=9927329 ZnO]


== Project goals ==


Describe project goals here.
== Purification Methods/ Testing Process ==


To make a numbered list use the pound sign:
== Ink Properties ==
# Like this
# and like this
# See [[Help:Contents]] for more formatting code.


== Design ==
== In-Situ Applications ==


Describe your design here.
== Applications ==
 
The application of quantum dots in LED displays is still relatively new, therefore, the initial applications may begin with larger displays. Larger displays do not require as high of a resolution, making the precision less critical. Quantum dots could be included in billboards, sports arenas, traffic management, festivals, theaters, and scoreboards <ref>[http://www.leddisplays.ie/LED_applications.htm LED Displays-Applications] </ref>.


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=== Next level heading ===
You may need deeper level headings.  Just keep adding equal signs to get that.


== Costs ==
== Costs ==

Revision as of 22:23, 15 October 2013

Sample photo caption.
You can put an abstract (a brief description of your project) here.

Semiconducting Materials

For the manufacturing of quantum dot LED (QLED) displays, the quantum dots will have been created prior to 3D printing. The quantum dots will be made of the semiconductor, cadmium selenide/zinc sulfide (CdSe/ZnS), which consists of CdSe core and a ZnS shell. The ZnS shell on the quantum dot acts as a protective barrier between the core, which is responsible for optical emission, and the surrounding material [1]. Four sizes of quantum dots corresponding to four colors (red, yellow, orange, green) of emitted light will be purchased from mkNano. The smallest quantum dots will be purchased from ------ since mknano did not offer CdSe/ZnS quantum dots in the size range that will emit blue light.

The CdSe/ZnS quantum dots will be 3D printed on a crystalline ZnO wafer which will act as the electron injection layer. ZnO was chosen for its favorable band gap energy and work function [2]. The ZnO wafer substrate will be purchased from Precision Micro-Optics.

The quantum dot suspensions used in this project will use water as the solvent. Some success has been realized by Haverinen et al. [3] in inkjet printing "CdSe core and CdS/ZnS double shell" quantum dots on a "cross-linkable poly-TPD [poly(N,N′-bis(4-butylphenyl-N,N′-bis(phenyl)benzidine)]" hole injection layer using chlorobenzene as a solvent. Table 1 compares various properties of chlorobenzene and water to show why water was chosen as a solvent.

Solvent Vapor Pressure Surface Tension Density Viscosity
Chlorobenzene 8.8 Torr (20°C) 33.28 dyn/cm (20°C) 1.1 g/cm3 0.0008 Pa*s (20°C)
Water 17.54 Torr (20°C) 72.8 dyn/cm (20°C) 1.0 g/cm3 0.001 Pa*s (20°C)


3D Printing CdSe/ZnS Quantum Dots

The focus of this project is on the viability of 3D printing the quantum dot layer (CdSe/ZnS) on the electron injection layer (ZnO wafer). The other layers (cathode, hole injection layer, anode) are beyond the scope of this project. Steps involving the other layers are for clarity only.

Note: All the quantum dot colors could not be purchased from the same manufacturer. mkNano did not offer a small enough quantum dot to emit blue light.

Steps:

  • Acquire materials
  • 3D print the cathode layer to the desired size
  • 3D print the electron injection layer (ZnO crystalline wafer Precision Micro-Optics) on top of the cathode
    • The electron injection layer will be 20 mm x 20 mm
  • Package the 5 quantum dot colors onto a vehicle (much like an inkjet printer)
  • Print the quantum dots into a display array
  • 3D print a hole injection layer onto the quantum dot layer
  • Print the final transparent anode layer onto the hole injection layer

Materials Saftey Data Sheets

Chemicals & Compounds Used


Purification Methods/ Testing Process

Ink Properties

In-Situ Applications

Applications

The application of quantum dots in LED displays is still relatively new, therefore, the initial applications may begin with larger displays. Larger displays do not require as high of a resolution, making the precision less critical. Quantum dots could be included in billboards, sports arenas, traffic management, festivals, theaters, and scoreboards [4].


Costs

Material Unit Price Total Price
CdSe/ZnS* ..... .....
ZnO wafer ..... .....
.....

prepared in methanol*

Discussion

Your discussion.

Next steps

The next steps.

Conclusions

Your conclusions.

References

  1. http://onlinelibrary.wiley.com/doi/10.1002/smll.200800841/abstract;jsessionid=0CF7224BBDA4499616800CEBAAD19DD0.f02t02 Core/Shell Semiconductor Nanocrystals
  2. http://scitation.aip.org/content/aip/journal/apl/96/15/10.1063/1.3400224 Improvement of electron injection in inverted bottom-emission blue phosphorescent organic light emitting diodes using zinc oxide nanoparticles
  3. http://scitation.aip.org/content/aip/journal/apl/94/7/10.1063/1.3085771 Inkjet printing of light emitting quantum dots
  4. LED Displays-Applications

Contact details

Ajmcquar Kmwhalen Shaneamtu

Add your contact information.

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