Pentaarylcyclopentadienyl units as active units in resistive memory elements
View Patent ↗Polymers are described which exhibit a resistive hysteresis effect. The polymers include a polymer backbone to which pentaarylcyclopentadienyl radicals are bonded as side groups. A resistive memory element is formed that includes the polymer as a storage medium. By applying a voltage, the memory element can be switched between a nonconductive and a conductive state.
1. A polymer having semiconductor properties and comprising a polymer backbone and pentaarylcyclopenta-1,3-dienyl radicals bonded as side groups to the polymer backbone, wherein each pentaarylcyclopenta-1,3-dienyl radical is bonded as a side group to the polymer backbone via a bonding group of one of the phenyl groups of the pentaarylcyclopenta-1,3-dienyl radical and the polymer further includes protic groups bonded to the polymer backbone.
2. The polymer of claim 1 , wherein the pentaaryl-cyclopenta-1,3-dienyl radical includes a structure as defined by formula I:
wherein each R 1 is the same or different at each location of the radical structure and is independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group including 1 to 10 carbon atoms, an aryl group including 5 to 20 carbon atoms, and an alkoxy group including 1 to 10 carbon atom.
3. The polymer of claim 2 , wherein the polymer is formed by copolymerization of a first comonomer that includes a polymerizable carbon-carbon double bond and a pentaarylcyclopenta-1,3-dienyl radical and at least one second comonomer that includes a polymerizable carbon-carbon double bond.
4. The polymer of claim 3 , wherein the first comonomer includes the structure of the formula I which forms a side group bonded to the polymer backbone, and the bonding group of one of the phenyl rings of the structure of the formula I comprises a vinyl group or a (meth)acryloyloxy group.
5. The polymer of claim 3 , wherein the second comonomer includes a protic group.
6. The polymer of claim 3 , wherein the second comonomer is selected from the group consisting of p-styrenesulfonic acid, (meth)acrylic acid, vinylpyridine and vinylpyrrolidone.
7. The polymer of claim 3 , wherein the first comonomer and the second comonomer are contained in the polymer in a molar ratio of from 1:1 to 100:1.
8. The polymer of claim 1 , wherein the polymer backbone comprises carbon atoms.
9. The polymer of claim 1 , wherein the polymer is formed by copolymerization of at least two different comonomers such that the polymer comprises a first group and a second group, the first group including the structure of formula I which forms a side group bonded to the polymer backbone, the bonding of one of the phenyl rings of the structure of formula I comprises a vinyl group or a (meth)acryloyloxy group, and the second group comprises at least one protic group.
10. The polymer of claim 9 , wherein the second group comprises one of p-styrenesulfonic acid, (meth)acrylic acid, vinylpyridine, and vinylpyrrolidone.
11. A resistive memory element comprising a memory cell that includes at least one actuatable first contact, one second contact and one storage medium arranged between the first contact and the second contact, wherein the storage medium is formed from the polymer of claim 1 .
12. The resistive memory element of claim 11 , wherein the first contact and the second contact comprise different materials.
13. The resistive memory element of claim 11 , wherein each of the first contact and the second contact comprises a metal.
14. The resistive memory element of claim 11 , further comprising a resistor with a constant resistance that is connected in series with the memory cell.
15. A memory field comprising at least two memory elements of claim 11 and a control device, wherein the memory field is configured for switching between two information states, and the control device is configured to control the information state of each memory element.