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1Step 1
The first thing I do is take pieces of ITO (Indium-Tin Oxide) glass and figure out which side has the conductive coating. Then I apply a small piece of kapton tape to the edge. Each side will make up one cathode and one anode side for a given device. The kapton tape ensures both sides have an uncoated area for attaching an electrode to test the device.
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2Step 2
Each slide is then cleaned using solvent and dried off using nitrogen gas.
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3Step 3
This is my nitrogen gas gun, done on the cheap. It was built using a filtered pipette tip, a gas flow limit/monitor, and a momentary switch attached to a solenoid (not pictured) on the gas line.
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4Step 4
This N2 tank supplies both the gas gun and the spin coater.
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5Step 5
The slides are then heated at 140C for about 10 minutes.
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6Step 6
During some of these steps I wear an organic respirator, as well as chemical safety goggles. All of the work is done inside a fume hood with the fan on during all spin coating and some drying steps.
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7Step 7
The process I use to lay down most of the materials I use to make OLEDs is called spin coating. It is roughly what it sounds like - the substrate (the ITO glass) is spun at a high speed, in an atmosphere of nitrogen gas. The material to be deposited is dissolved in a solvent, and either dropped onto the glass before the spinning starts, or while spinning for a different coating effect. Most of the solvent evaporates during this process, and combines with the (inert) nitrogen gas to leave the fume hood.
I use Toluene. It's scary stuff, hence the fume hood and organic respirator. It's a trade off between being the safest solvent I could find, as well as being a solvent that leaves very little material behind after evaporation during spin coating. This is an important part of creating a successful device.
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8Step 8
When working with materials to be spin coated, and creating spin-coatable solutions, I use an auto-pipetter with a filtered pipette tip. It's real handy for getting the right amount, and I got these on ebay for cheap!
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9Step 9
This is the material I'm going to dissolve in Toluene - it is a red emitting polymer, Poly[{9,9-dihexyl-2,7-bis(1-cyanovinylene)fluorenylene}-alt-co-{2,5-bis(N,N'-diphenylamino)-1,4-phenylene}]. Unfortunately I don't know of a short name for it. Let's call it PFO-RED for short.
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10Step 10
Just an empty vial.
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I came across this wondering how OLEDs are made for brake lights. This is a pretty awesome write up. Thanks man.
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Hello and thanks . Did you measure the light intensity, driving voltage and the lifetime?
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