Methods for depositing nanomaterial, methods for fabricating a device, methods for fabricating an array of devices and compositions
View Patent ↗A method comprising depositing an ink comprising a nanomaterial, a material capable of transporting charge, and a liquid vehicle from a micro-dispenser onto a layer of a device is disclosed. A method comprising depositing an ink comprising a nanomaterial, a material capable of transporting charge, and a liquid vehicle from a micro-dispenser onto a second material capable of transporting charge in a predetermined arrangement is also disclosed. In certain preferred embodiments, the nanomaterial comprises semiconductor nanocrystals. In certain preferred embodiments, a micro-dispenser comprises an inkjet printhead. Methods for fabricating devices including a nanomaterial and method for fabricating an array of devices including a nanomaterial are also disclosed. An ink composition including a nanomaterial, a material capable of transporting charge, and a liquid vehicle is also disclosed.
1. A method of depositing an ink comprising an emissive material including a nanomaterial comprising quantum confined semiconductor nanocrystals that emit light having a predetermined wavelength, a material capable of transporting charge, and a liquid vehicle onto a layer of a light-emitting device, the method comprising:
depositing the ink from a micro-dispenser onto the layer of the light-emitting device in a predetermined arrangement, wherein the layer comprises a second material capable of transporting charge and wherein the liquid vehicle included in the ink comprises an organic solvent in which the second material capable of transporting charge included in the layer is at least partially soluble, and wherein at least a portion of the nanomaterial and the material capable of transporting charge that are included in the ink is at least temporarily mixed in a portion of the second material capable of transporting charge that is soluble in the organic solvent.
2. A method in accordance with claim 1 further comprising removing at least a portion of the liquid vehicle from the ink.
3. A method in accordance with claim 1 wherein at least a portion of the liquid vehicle is removed such that at least a portion of the second material capable of transporting charge remains mixed with the nanomaterial and material capable of transporting charge that are included in the ink.
4. A method in accordance with claim 2 wherein the liquid vehicle is removed such that the nanomaterial phase separates to form a layer of nanomaterial at or near the surface of the second material capable of transporting charge.
5. A method in accordance with claim 2 wherein the liquid vehicle is selected such that, upon removal of the liquid vehicle, the surface of the layer comprising the second material capable of transporting charge is planar.
6. A method in accordance with claim 1 wherein the second material capable of transporting charge comprises a small molecule material.
7. A method in accordance with claim 6 wherein the second material capable of transporting charge comprises a polymer.
8. A method in accordance with claim 6 wherein the second material capable of transporting charge comprises an inorganic material.
9. A method in accordance with claim 1 wherein the second material capable of transporting charge comprises a material capable of transporting electrons.
10. A method in accordance with claim 1 wherein the second material capable of transporting charge comprises a material capable of transporting holes.
11. A method in accordance with claim 1 wherein the material capable of transporting charge has a triplet energy which is at least greater than the bandgap of the semiconductor nanocrystals included in the ink.
12. A method in accordance with claim 1 wherein the layer of the device is disposed over a substrate including an electrode.
13. A method in accordance with claim 1 wherein the micro-dispenser comprises an inkjet printhead and the ink is deposited by inkjet processing.
14. A method in accordance with claim 1 wherein more than one ink is deposited onto the layer, wherein each ink comprises a nanomaterial comprising semiconductor nanocrystals.
15. A method in accordance with claim 14 wherein the each ink comprises a nanomaterial comprising semiconductor nanocrystals that have an emission wavelength distinguishable from the emission wavelength of the semiconductor nanocrystals included in each of the other inks.
16. A method in accordance with claim 1 wherein the second material capable of transporting charge included in the layer of the device onto which the ink is deposited comprises carbon nanotubes.
17. A method in accordance with claim 1 wherein the second material capable of transporting charge included in the layer of the device onto which the ink is deposited comprises a carbon nanotube/polymer blend or hybrid.
18. A method in accordance with claim 1 wherein the second material capable of transporting charge included in the layer of the device onto which the ink is deposited comprises an organic nanocrystal.