Delivering organic powder to a vaporization zone
View Patent ↗A method for vaporizing organic materials and condensing them onto a surface to form a layer, comprising: providing a quantity of organic material in a powdered form in a first container; fluidizing the organic material in the first container and transferring such fluidized material to an auger structure; and rotating at least a portion of the auger structure to transfer fluidized powder from the first container along a feeding path to a vaporization zone where such powder is vaporized and delivered to the substrate to form the layer.
1. A method for forming an OLED device comprising:
a) providing a substrate and a first electrode over the substrate;
b) forming a first organic layer over the first electrode by:
i) providing first particulate organic material in a first feeding path; and
ii) mechanically transferring material consisting of the first particulate organic material along the first feeding path to a first vaporization zone using an auger structure, wherein the first vaporization zone is maintained at a constant temperature and the feed rate of the first particulate organic material to the first vaporization zone controls the deposition rate of the first vaporized organic particulate material; and
c) forming a second electrode over the first organic layer.
2. The method of claim 1 wherein the first organic layer is a light emitting layer.
3. The method of claim 2 wherein the first particulate organic material includes at least a host material and a dopant material.
4. The method of claim 1 wherein the temperature of the first particulate organic material in the first feeding path is maintained below the desired vaporization temperature.
5. The method of claim 1 further including metering, at a controlled volumetric rate or pressure, the first particulate organic into the vaporization zone.
6. The method of claim 1 further comprising
d) before forming the second electrode, forming a second organic layer over the first electrode by:
i) providing second particulate organic material in a second feeding path; and
ii) mechanically transferring organic material consisting of the particulate material along the second feeding path to a second vaporization zone using an auger structure, wherein the second vaporization zone is maintained at a constant temperature and the feed rate of the particulate organic material to the second vaporization zone controls the deposition rate of the second vaporized organic particulate material.
7. The method of claim 6 wherein the second organic layer is an electron-transport layer, an electron-injecting layer, a hole-transport layer or a hole-injecting layer.
8. The method of claim 1 further including selecting the first feeding path orientation and providing an auger structure along such first feeding path.
9. The method of claim 8 wherein mechanically transferring the first particulate organic material comprises rotating at least a portion of the auger structure.
10. The method of claim 9 wherein the auger structure extrudes the first particulate organic material in a solid form.
11. The method of claim 10 wherein the solid fonn has a tubular shape that is maintained after exiting the auger structure.
12. The method of claim 10 where in the solid form acts as a vapor seal preventing pressurized vapor from flowing back into the auger structure.
13. The method of claim 8 wherein the first feeding path orientation is horizontal.