# US 2019/0378977 A1 · Ferroelectric strain based phase-change device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0378977 A1 - Document ID: US20190378977A1 - Status: Published application - Kind: A1 - Application number: 16/433,534 - Filed: 2019-06-06 - Published: 2019-12-12 - Earliest claimed: 2018-06-12 - Assignees: University of Rochester - Applicants: University of Rochester - Inventors: Stephen M. Wu; Wenhui Hou; Arfan Sewaket; Ahmad Azizimanesh - Web page: https://patentgrep.com/patent/US20190378977A1 ## CPC - H10N 70/235: {between different crystalline phases, e.g. cubic and hexagonal} - H10N 70/882: {Compounds of sulfur, selenium or tellurium, e.g. chalcogenides} - H10B 51/30: characterised by the memory core region - H10B 63/30: {comprising selection components having three or more electrodes, e.g. transistors} - H10N 70/253: {having three or more electrodes, e.g. transistor-like devices} - H10N 70/823: {adapted for essentially horizontal current flow, e.g. bridge type devices} - H10N 70/8828: {Tellurides, e.g. GeSbTe} - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR - H10B: ELECTRONIC MEMORY DEVICES ## Abstract A phase transition optical device includes a substrate or a thin film of a ferroelectric material. A transition metal dichalcogenide is disposed over and in contact with the substrate or the thin film. The transition metal dichalcogenide has a semiconducting state with a first optical property and a semimetallic state with a second optical property. The semiconducting state or the semimetal state is selectable by applying a voltage across the ferroelectric material to induce a strain in the transition metal dichalcogenide via the ferroelectric material. A transistor device, integrated memory device, and a phase transition optical device are also described. ## Claims ### Claim 1 A phase transition device comprising: a substrate or a thin film of a ferroelectric material; and a transition metal dichalcogenide disposed over and in contact with said substrate or said thin film, said transition metal dichalcogenide having a semiconducting state and a semimetallic state, said semiconducting state or said semimetal state selectable by applying a voltage across said ferroelectric material to induce a strain in said transition metal dichalcogenide via said ferroelectric material. ### Claim 2 (depends on 1) The phase transition device of claim 1, comprising an electrical contact terminal disposed at either side of a strip of said transition metal dichalcogenide. ### Claim 3 (depends on 1) The phase transition device of claim 1, wherein said phase transition device is a field effect transistor. ### Claim 4 (depends on 3) The phase transition device of claim 3, wherein said transition metal dichalcogenide comprises a MoTe2 material. ### Claim 5 (depends on 1) The phase transition device of claim 1, wherein said ferroelectric material comprises a single crystal of an oxide substrate of a relaxor ferroelectric material. ### Claim 6 (depends on 1) The phase transition device of claim 1, wherein said ferroelectric material comprises a PMN-PT material. ### Claim 7 (depends on 1) A plurality of phase transition devices according to claim 1 disposed in an integrated circuit. ### Claim 8 (depends on 1) The phase transition device of claim 1, wherein a non-volatile phase transition device remains in a previously selected state in an absence of electrical power. ### Claim 9 A transistor device comprising: a substrate or a thin film of a ferroelectric material having a first surface and a second surface; a gate terminal electrically coupled to and disposed on said second surface; and a section of a transition metal dichalcogenide disposed over and in contact with said substrate or said thin film, said section of a transition metal dichalcogenide having a source terminal at a first end of said section of a transition metal dichalcogenide and a drain terminal at a second end of said section of a transition metal dichalcogenide, said section of a transition metal dichalcogenide having a semiconducting state and a semimetallic state, said semiconducting state or said semimetallic state selectable by applying a voltage between said gate terminal and said source terminal or between said gate terminal and said drain terminal to induce a strain in said transition metal dichalcogenide via said ferroelectric material. ### Claim 10 (depends on 9) The transistor device of claim 9, wherein a non-volatile transistor device remains in a previously selected state in an absence of electrical power. ### Claim 11 (depends on 9) The transistor device of claim 9, wherein there is a substantially non-conducting path between said drain terminal and said source terminal in said semiconducting state. ### Claim 12 (depends on 9) The transistor device of claim 9, wherein there is a substantially conducting path between said drain terminal and said source terminal in said semimetallic state. ### Claim 13 (depends on 9) The transistor device of claim 9, wherein a phase transition device comprises a field effect transistor. ### Claim 14 (depends on 9) The transistor device of claim 9, wherein said transition metal dichalcogenide comprises a MoTe2 material. ### Claim 15 (depends on 9) The transistor device of claim 9, wherein said ferroelectric material comprises a single crystal of an oxide substrate of a relaxor ferroelectric material. ### Claim 16 (depends on 9) The transistor device of claim 9, wherein said ferroelectric material comprises a PMN-PT material. ### Claim 17 (depends on 9) A plurality of transistor devices according to claim 9 disposed in an integrated circuit. ### Claim 18 (depends on 17) The transistor devices of claim 17, wherein said plurality of transistor devices comprise a sub nanosecond state change switching speed. ### Claim 19 An integrated memory device comprising: a substrate or a thin film of a ferroelectric material having a first surface and a second surface; a plurality of non-volatile transistor devices which remain in a previously selected state in an absence of electrical power, each non-volatile transistor device comprising: a gate terminal electrically coupled to and disposed on said second surface; and a section of a transition metal dichalcogenide disposed over and in contact with said substrate or said thin film, said section of a transition metal dichalcogenide having a source terminal at a first end of said section of a transition metal dichalcogenide and a drain terminal at a second end of said section of a transition metal dichalcogenide, said section of a transition metal dichalcogenide having a semiconducting state and a semimetallic state, said semiconducting state or said semimetallic state selectable by applying a voltage between said gate terminal and said source terminal or between said gate terminal and said drain terminal to induce a strain in said transition metal dichalcogenide via said ferroelectric material. ### Claim 20 A phase transition optical device comprising: a substrate or a thin film of a ferroelectric material; and a transition metal dichalcogenide disposed over and in contact with said substrate or said thin film, said transition metal dichalcogenide having a semiconducting state with a first optical property and a semimetallic state with a second optical property, said semiconducting state or said semimetal state selectable by applying a voltage across said ferroelectric material to induce a strain in said transition metal dichalcogenide via said ferroelectric material. ### Claim 21 (depends on 20) The phase transition optical device of claim 20, wherein said first optical property comprises a substantially opaque optical state, and said second optical property comprises an at least translucent optical state.