# US 11,910,718 B2 · Multilayered piezoelectric thin film element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,910,718 B2 - Document ID: US11910718B2 - Status: Granted - Kind: B2 - Application number: 17/014,808 - Filed: 2020-09-08 - Published: 2021-01-14 - Granted: 2024-02-20 - Earliest claimed: 2014-11-04 - Assignees: Xaar Technology Limited - Applicants: Xaar Technology Limited - Inventors: Peter Mardilovich; Susan Trolier-McKinstry - Web page: https://patentgrep.com/patent/US11910718B2 ## CPC - H10N 30/8554: {Lead-zirconium titanate [PZT] based} - B41J 2/14233: {of film type, deformed by bending and disposed on a diaphragm} - H10N 30/06: Forming electrodes or interconnections, e.g. leads or terminals - H10N 30/078: by sol-gel deposition - H10N 30/2047: {Membrane type} - H10N 30/704: {based on piezoelectric or electrostrictive films or coatings} - H10N 30/87: Electrodes or interconnections, e.g. leads or terminals - B41J 2002/14266: {Sheet-like thin film type piezoelectric element} - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A piezoelectric thin film element having a first electrode, a second electrode and a piezoelectric thin film between the electrodes, wherein the thin film comprises a laminate having two or more piezoelectric thin film layers and wherein a first thin film layer is doped by one or more dopants and a second film layer is doped by one or more dopants and wherein at least one dopant of the second thin film layer is different from the dopant or dopants of the first thin film layer. ## Claims ### Claim 1 A piezoelectric thin film element comprising: a first electrode; a second electrode; and a piezoelectric thin film having a perovskite ABO3 crystal structure, the piezoelectric thin film being arranged between the first and second electrodes and in contact with the first and second electrodes, wherein the piezoelectric thin film comprises a laminate having two or more piezoelectric thin film layers and wherein a first thin film layer is singly doped by a first donor dopant and a second thin film layer is singly doped by a second dopant selected from one of dopant type consisting of one of donor dopants, acceptor dopants and isovalent dopants, wherein the second dopant is different from the first donor dopant; and the piezoelectric thin film is configured to be deformed upon application of a predetermined drive voltage between the first and second electrodes. ### Claim 2 (depends on 1) The piezoelectric thin film element according to claim 1, in which the second dopant is selected from the dopant type consisting of acceptor dopants. ### Claim 3 (depends on 1) The piezoelectric thin film element according to claim 1, wherein the first donor dopant is one of Nb5+ and Hf4+ and the second dopant is one of Mn2+, Mn3+, and Mn4+. ### Claim 4 (depends on 1) The piezoelectric thin film element according to claim 1, in which all thin film layers comprise lead zirconate titanate (PZT). ### Claim 5 (depends on 1) The piezoelectric thin film element according to claim 1, in which the first dopant and the second dopant occupy the same or different co-ordination sites (A-site or B-site) in the perovskite ABO3 crystal structure. ### Claim 6 (depends on 1) The piezoelectric thin film element according to claim 1, wherein: the laminate comprises at least three piezoelectric thin film layers; the laminate comprises one thin film layer which is undoped and contact the first electrode and the first thin film layer. ### Claim 7 (depends on 1) The piezoelectric thin film element according to claim 1, wherein: the laminate comprises at least three piezoelectric thin film layers; and a third film layer comprises the first dopant of the first thin film layer and the second dopant of the second thin film layer. ### Claim 8 (depends on 1) The piezoelectric thin film element according to claim 1, in which the first donor dopant and the second dopant are of a different dopant type. ### Claim 9 (depends on 1) The piezoelectric thin film element according to claim 1, in which the laminate comprises one or more further thin film layers which are singly doped by dopants of the same or different dopant type. ### Claim 10 (depends on 1) The piezoelectric thin film element according to claim 1, in which the laminate comprises two or more thin film layers which are alternately doped by the first donor dopant and a second donor dopant or by the first donor dopant and a dopant of a second dopant type. ### Claim 11 (depends on 10) The piezoelectric thin film element according to claim 10, in which any two adjacent thin film layers are alternately doped by the first donor dopant and a dopant of the second dopant type. ### Claim 12 (depends on 10) The piezoelectric thin film element according to claim 10, wherein: one thin film layer which is doped is adjacent a thin film layer which is undoped or doped and any two sequential thin film layers which are doped, are alternately doped by the first donor dopant and a dopant of a second dopant type; and the doping concentration of the thin film layers decreases towards the first electrode. ### Claim 13 (depends on 10) The piezoelectric thin film element according to claim 10, wherein: the laminate comprises a plurality of piezoelectric thin film layers; a first series of adjacent thin film layers which are doped by the first donor dopant and a second series of adjacent thin film layers which are doped by a dopant of a second dopant type, the second dopant type being an acceptor donor dopant; the concentration of the acceptor dopant in thin film layers decreases towards the first electrode; and the concentration of the first donor dopant increases towards the first electrode. ### Claim 14 (depends on 10) The piezoelectric thin film element according to claim 10, in which similarly doped thin film layers define a gradient in dopant concentration across thin film layers. ### Claim 15 (depends on 14) The piezoelectric thin film according to claim 14, in which the dopant concentration increases or decreases from the first electrode to the second electrode. ### Claim 16 (depends on 14) The piezoelectric thin film element according to claim 14, in which the dopant concentration increases from the first electrode and decreases to the second electrode. ### Claim 17 (depends on 1) The piezoelectric thin film element according to claim 1, in which one or more thin film layers define a gradient in dopant concentration within the thin film layer. ### Claim 18 (depends on 1) An actuator for a printhead, wherein the actuator comprises the piezoelectric thin film element according to claim 1. ### Claim 19 (depends on 18) A printhead comprising the actuator of claim 18. ### Claim 20 A method for manufacturing a piezoelectric thin film element comprising: forming a first piezoelectric thin film layer having perovskite crystal structure (ABO3) on a first electrode; forming one or more piezoelectric thin film layers having the perovskite ABO3 crystal structure on the first piezoelectric thin film layer to form a laminate comprising a plurality of piezoelectric thin film layers; forming a second electrode on top the plurality of piezoelectric thin film layers; and coupling a controller to the first electrode and the second electrode, wherein: the first piezoelectric thin film layer is singly doped by a first donor dopant, a second layer of the plurality of piezoelectric thin film layers is singly doped by a second dopant different from the first donor dopant of the first thin film layer, and the controller is configured to apply a drive voltage that causes the plurality of piezoelectric thin film layers to deform.