# US 10,374,128 B2 · Electrical contacts to light-emitting diodes for improved current spreading and injection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,128 B2 - Document ID: US10374128B2 - Status: Granted - Kind: B2 - Application number: 15/103,150 - Filed: 2014-12-12 - Published: 2016-11-03 - Granted: 2019-08-06 - Earliest claimed: 2013-12-12 - Assignees: Terahertz Device Corporation - Applicants: Terahertz Device Corporation - Inventors: Mark S. Miller - Web page: https://patentgrep.com/patent/US10374128B2 ## CPC - H10H 20/831: characterised by their shape - H10H 20/813: having a plurality of light-emitting regions, e.g. multi-junction LEDs or light-emitting devices having photoluminescent regions within the bodies - H10H 20/824: comprising only Group III-V materials, e.g. GaP - H10H 20/832: characterised by their material - H10H 20/857: Interconnections, e.g. lead-frames, bond wires or solder balls - H10K 50/88: Terminals, e.g. bond pads - H10H 20/032: {of electrodes} - H10H 20/0364: {of interconnections} - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract An optoelectric device can comprise a substrate and at least one junction configured to provide an active region within the substrate. Additionally, the device can comprise a metal-mesh semiconductor electrical contact structure attached to a surface of the substrate. The metal-mesh semiconductor electrical contact structure can further comprise a mesh line width, a mesh opening size, and a mesh thickness. ## Claims ### Claim 1 An optoelectric device, comprising: a substrate; at least one junction configured to provide an active region within the substrate; and a metal-mesh semiconductor electrical contact structure attached to a surface of the substrate, wherein the metal-mesh semiconductor electrical contact structure comprises a plurality of mesh lines that define a grid of uniformly distributed mesh openings across the surface of the substrate, wherein the mesh openings comprise a mesh opening size, wherein the metal-mesh semiconductor electrical contact structure comprises a mesh thickness, and wherein the plurality of mesh lines comprises a first plurality of mesh lines that define rows and columns of the grid of uniformly distributed mesh openings having a first mesh line width and a second one or more thicker metal mesh lines having a second mesh line width thicker than the first mesh line width, the second one or more thicker metal mesh lines extending from a wire bonding pad. ### Claim 2 (depends on 1) The device of claim 1, wherein the grid of uniformly distributed mesh openings comprises a plurality of square mesh openings. ### Claim 3 (depends on 1) The device of claim 1, wherein the mesh thickness is configured such that a spreading length for a composite contact is greater than a size of the optoelectric device. ### Claim 4 (depends on 1) The device of claim 1, wherein the metal-mesh semiconductor electrical contact structure comprises an Au—Ti layer. ### Claim 5 (depends on 1) The device of claim 1, further comprising an n-type semiconductor current spreading contact layer comprising InAs. ### Claim 6 (depends on 1) The device of claim 1, further comprising a p-type semiconductor current spreading contact layer comprising GaSb. ### Claim 7 (depends on 1) The device of claim 1, further comprising cascaded LED emission junctions. ### Claim 8 (depends on 1) The device of claim 1, wherein the optoelectric device comprises semiconducting materials that emit light in a mid-infrared portion of the electromagnetic spectrum. ### Claim 9 (depends on 8) The device of claim 8, wherein the mesh opening size comprises a width of 50 μm, the first mesh line width comprises a width of 5 μm wide, and the mesh thickness comprises a thickness of 1 μm. ### Claim 10 (depends on 9) The device of claim 9, wherein the optoelectric device comprises ten cascaded junctions operating at a current density of 100 A/cm2, a square die with a length of 1 mm, and an ideality factor of 1.5. ### Claim 11 (depends on 1) The device of claim 1, wherein the optoelectric device comprises cascaded LED emission junctions that comprise semiconducting materials that emit light in a visible and ultraviolet portion of the electromagnetic spectrum. ### Claim 12 (depends on 11) The device of claim 11, wherein the mesh opening size comprises a width of 50 μm, the first mesh line width comprises a width of 5 μm wide, and the mesh thickness comprises a thickness of 1 μm. ### Claim 13 (depends on 12) The device of claim 12, wherein the optoelectric device operates at a current density of 500 A/cm2, and comprises a square die with a length of 1 mm, and an ideality factor of 1.1. ### Claim 14 (depends on 1) The device of claim 1, wherein the optoelectric device comprises cascaded organic LED emission junctions. ### Claim 15 A light-emitting diode, comprising: at least one substrate comprising a semiconducting material that emits light in a mid-infrared portion of the electromagnetic spectrum; a plurality of cascaded LED emission junctions; and a metal-mesh semiconductor electrical contact structure attached to a surface of the substrate, wherein the metal-mesh semiconductor electrical contact structure comprises a central-positioned wire bonding pad and a plurality of mesh lines that define a grid of uniformly distributed mesh openings across the surface of the substrate, wherein the mesh openings have mesh opening sizes based on a number of junctions from the plurality of cascaded LED emission junctions, wherein the metal-mesh semiconductor electrical contact structure comprises a plurality of uniform mesh thicknesses, and wherein the plurality of mesh lines comprises a first plurality of mesh lines that define rows and columns of the grid of uniformly distributed mesh openings having a first mesh line width and a second one or more thicker metal mesh lines having a second mesh line width thicker than the first mesh line width, the second one or more thicker metal mesh lines extending from the central-positioned wire bonding pad. ### Claim 16 (depends on 15) The light-emitting diode of claim 15, wherein the semiconducting material comprises a material selected from a group consisting of InAs, GaSb, and AlSb. ### Claim 17 (depends on 15) The light-emitting diode of claim 15, wherein the plurality of uniform mesh opening sizes comprise widths of 50 μm, the first plurality of uniform mesh line widths comprise widths of 5 μm wide, and the plurality of uniform mesh thicknesses comprise thicknesses of 1 μm. ### Claim 18 A method for manufacturing a metal-mesh semiconductor electrical contact structure for a light-emitting diode, the method comprising: determining an operating current of the light-emitting diode; determining a size of the light-emitting diode; calculating a mesh thickness for the metal-mesh semiconductor electrical contact structure such that a spreading length for a composite contact is greater than the size of the light-emitting diode; and creating the metal-mesh semiconductor electrical contact structure with the calculated mesh thickness, wherein the metal-mesh semiconductor electrical contact structure also comprises: a plurality of mesh lines that define a grid of uniformly distributed mesh openings across a surface of a substrate and a central-positioned wire bonding pad, and wherein the plurality of mesh lines comprises a first plurality of mesh lines that define rows and columns of the grid of uniformly distributed mesh openings having a first mesh line width and a second one or more thicker metal mesh lines having a second mesh line width thicker than the first mesh line width, the second one or more thicker metal mesh lines extending from the central-positioned wire bonding pad. ### Claim 19 (depends on 18) The method of claim 18, further comprising configuring the metal-mesh semiconductor electrical contact structure to increase junction injection resistance compared to contact spreading resistance. ### Claim 20 (depends on 18) The method of claim 18, wherein the metal-mesh semiconductor electrical contact structure comprises a mesh opening width of 50 μm, a mesh line width of 5 μm wide, and a mesh thicknesses of 1 μm.