CEM switching device
Subject matter herein disclosed relates to a method for the manufacture of a CEM switching device providing that the CEM layer comprises a doped metal compound substantially free from metal wherein ions of the same metal element are present in different oxidation states. The method may provide a CEM layer which is born on and capable of switching with operating voltages below 2.0V.
1. A CEM switching device comprising a conductive substrate, a conductive overlay and a layer of a correlated electron material (CEM) interposed there between wherein the CEM layer comprises a doped compound of a d- or f-block element comprising ions of the same d- or f-block element in different oxidation states and less than 5 atom % of free d- or f-block element, the free d- or f-block element being unbound and in a zero oxidation state.
2. A CEM switching device according to claim 1 , wherein the compound comprises two different ions of the same d- or f-block element and the different oxidation states are +2 and +3.
3. A CEM switching device according to claim 1 , wherein the compound comprises three different ions of the same d- or f-block element and the different oxidation states are +1, +2 and +3.
4. A CEM switching device according to claim 1 , wherein the compound comprises two different ions of the same d- or f-block element in ratio between 1:5 and 5:1.
5. A CEM switching device according to claim 1 , wherein the compound comprises nickel oxide containing nickel ions in oxidation states +2 and +3.
6. A CEM switching device according to claim 5 , wherein the nickel oxide contains nickel ions in oxidation state +1.
7. A CEM switching device according to claim 1 , wherein the CEM layer is doped with a dopant providing a back-donating ligand.
8. A CEM switching device according to claim 1 , wherein the CEM layer is born on.
9. A CEM switching device according to claim 1 , wherein the switching voltage of the device is less than or equal to 2.0 V.
10. A CEM switching device according to claim 1 , wherein the compound comprises one or more of an oxide of aluminum, cadmium, chromium, cobalt, copper, gold, iron, manganese, mercury, molybdenum, nickel, palladium, rhenium, ruthenium, silver, tantalum, tin, titanium, vanadium, yttrium, ytterbium and zinc.
11. A CEM switching device according to claim 10 , wherein the oxide is doped by a carbon-containing or nitrogen-containing dopant.