Erasing and programming an organic memory device and method of fabricating
View Patent ↗An organic memory cell made of two electrodes with a selectively conductive media between the two electrodes is disclosed. The selectively conductive media contains an organic layer and passive layer. The selectively conductive media is programmed by applying bias voltages that program a desired impedance state for a memory cell. The desired impedance state represents one or more bits of information and the memory cell does not require constant power or refresh cycles to maintain the desired impedance state. Furthermore, the selectively conductive media is read by applying a current and reading the impedance of the media in order to determine the impedance state of the memory cell. Methods of making the organic memory devices/cells, methods of using the organic memory devices/cells, and devices such as computers containing the organic memory devices/cells are also disclosed.
1. An organic memory device comprising:
a first electrode;
a selectively conductive media formed on the first electrode, the selectively conductive media facilitating migration of charge, the selectively conductive media comprising an organic material, and the charge comprising at least one of electrons and holes; and
a second electrode, wherein a selected voltage is applied to the first electrode and the second electrode in order to set an impedance state of the selectively conductive media;
wherein in a first state a positive charge in the selectively conductive media is collected near the first electrode, in a second state the positive charge is distributed uniformly in the selectively conductive media, and in a third state the positive charge in the selectively conductive media is collected near the second electrode.
2. The device of claim 1 , the selected voltage being one of a number of voltages that corresponds to the resulting impedance state.
3. The device of claim 1 , the impedance state being one of a number of available impedance states.
4. The device of claim 3 , the number of available impedance states corresponding to respective information content.
5. The device of claim 1 , the impedance state representing more than one bit of information.
6. The device of claim 1 , wherein an injection current is applied to the first electrode and the second electrode to read a current state of the organic memory device.
7. The device of claim 6 , the current state being one of a number of available states.
8. The device of claim 7 , the available states representing one or more bits of information.
9. The device of claim 1 , the selectively conductive media comprising a passive layer formed on the first electrode and an organic polymer layer formed on the passive layer.
10. The device of claim 9 , the passive layer comprising a plurality of individual passive layers.
11. The device of claim 9 , the passive layer contains Cu y S.
12. The device of claim 9 , the organic layer being a conjugated organic material.
13. The device of claim 9 , the organic layer being selected from the group comprising: polyacetylene, polyphenylacetylene, polydiphenylacetylene, polyaniline, poly(p-phenylene vinylene), polythiophene, polyporphyrins, porphyrinic macrocycles, thiol derivatized polyporphyrins, polymetallocenes, polyferrocenes, polyphthalocyanines, polyvinylenes, and polystiroles.
14. The device of claim 9 , the organic layer having a thickness of about 0.001 μm or more and about 5 μm or less.
15. The device of claim 9 , a thickness of the organic layer is about 1 to 500 times greater than a thickness of the passive layer.
16. The device of claim 1 , the first electrode comprising a material being selected from the group comprising aluminum, chromium, copper, germanium, gold, magnesium, manganese, indium, iron, nickel, palladium, platinum, silver, titanium, zinc, alloys thereof, indium-tin oxide, polysilicon, doped amorphous silicon, and metal silicides.
17. The device of claim 1 , thicknesses of the first electrode and the second electrode being about 0.01 μm or more and about 10 μm or less.
18. A method of fabricating an organic memory device comprising:
forming a first electrode on a substrate;
forming a selectively conductive media on the first electrode, the selectively conductive media includes a passive layer and an organic layer, the organic layer being substantially thicker than the passive layer; and
forming a second electrode on the selectively conductive media;
wherein the selectively conductive media facilitates migration of a charge wherein in a first state a positive charge of the selectively conductive media is accumulated near the first electron, in a second state the positive charge is dispersed in the selective conductive media, and in a third state the positive charge is accumulated near the second electrode.
19. The method of claim 18 , the organic layer formed via a chemical vapor deposition process.
20. The method of claim 18 , the organic layer formed via a gas phase reaction process.
21. The method of claim 18 , the organic layer formed via a spin coating process.
22. The method of claim 18 , further comprising applying a first voltage to the first electrode and the second electrode to set an impedance state of the memory device, the impedance state representing information content.
23. The method of claim 18 , further comprising applying a second voltage to the first electrode and the second electrode to determine an impedance state of the memory device, the impedance state representing information content.