# US 12,604,602 B2 · Display apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,604,602 B2 - Document ID: US12604602B2 - Status: Granted - Kind: B2 - Application number: 18/358,858 - Filed: 2023-07-25 - Published: 2024-02-08 - Granted: 2026-04-14 - Earliest claimed: 2022-07-26 - Assignees: LG Display Co., Ltd. - Applicants: LG Display Co., Ltd. - Inventors: Jeongeun Won; Seungryong Joung; Chunki Kim; Yosub Lee - Web page: https://patentgrep.com/patent/US12604602B2 ## CPC - H10K 50/13: comprising stacked EL layers within one EL unit - H10K 50/19: Tandem OLEDs - H10K 50/156: {comprising a multilayered structure} - H10K 50/16: Electron transporting layers - H10K 59/12: Active-matrix OLED [AMOLED] displays - H10K 2102/351: {Thickness} - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract A display apparatus according to an example embodiment of the present disclosure includes a cathode electrode over a substrate, a first emission part over the cathode electrode, the first emission part including a first electron transport layer, a first emission layer, a first hole transport layer, and a first charge generation layer, a second emission part over the first emission part, the second emission part including a second charge generation layer, a second electron transport layer, a second emission layer, a second hole transport layer, and a third charge generation layer, a third emission part over the second emission part, the third emission part including a fourth charge generation layer, a third electron transport layer, a third emission layer, and a third hole transport layer, and an anode electrode over the third emission part. A thickness of the third electron transport layer may be larger than a thickness of the second electron transport layer. ## Claims ### Claim 1 A display apparatus, comprising: a cathode electrode over a substrate; a first emission part over the cathode electrode, the first emission part including a first electron transport layer, a first emission layer, a first hole transport layer, and a first charge generation layer; a second emission part over the first emission part, the second emission part including a second charge generation layer, a second electron transport layer, a second emission layer, a second hole transport layer, and a third charge generation layer; a third emission part over the second emission part, the third emission part including a fourth charge generation layer, a third electron transport layer, a third emission layer, and a third hole transport layer; and an anode electrode over the third emission part, wherein a thickness of the third electron transport layer is larger than a thickness of the second electron transport layer. ### Claim 2 (depends on 1) The display apparatus of claim 1, wherein the thickness of the third electron transport layer is smaller than a thickness of the first electron transport layer. ### Claim 3 (depends on 1) The display apparatus of claim 1, wherein a refractive index of the third electron transport layer is in a range from 1.90 to 2.10, inclusive. ### Claim 4 (depends on 1) The display apparatus of claim 1, wherein a thickness of the second hole transport layer is larger than a thickness of the first hole transport layer and smaller than a thickness of the third hole transport layer. ### Claim 5 (depends on 1) The display apparatus of claim 1, further comprising: a fifth charge generation layer between the cathode electrode and the first electron transport layer. ### Claim 6 (depends on 5) The display apparatus of claim 5, wherein a sum of thicknesses of the first electron transport layer and the fifth charge generation layer is larger than a sum of thicknesses of the second charge generation layer and the second electron transport layer. ### Claim 7 (depends on 1) The display apparatus of claim 1, wherein a sum of thicknesses of the second charge generation layer and the second electron transport layer is smaller than a sum of thicknesses of the fourth charge generation layer and the third electron transport layer. ### Claim 8 (depends on 1) The display apparatus of claim 1, wherein at least one or more of the first hole transport layer, the second hole transport layer, or the third hole transport layer includes two or more hole transport layers. ### Claim 9 (depends on 8) The display apparatus of claim 8, wherein the third hole transport layer includes two or more hole transport layers, and among the two or more hole transport layers of the third hole transport layer, a thickness of a hole transport layer adjacent to the third emission layer is smaller than a thickness of a hole transport layer adjacent to the anode electrode. ### Claim 10 (depends on 1) The display apparatus of claim 1, wherein the cathode electrode is adjacent to the first electron transport layer and the anode electrode is adjacent to the third hole transport layer. ### Claim 11 (depends on 1) The display apparatus of claim 1, wherein at least two or more of the first emission layer, the second emission layer, or the third emission layer are configured to emit a same color light. ### Claim 12 (depends on 1) The display apparatus of claim 1, wherein the first emission layer and the third emission layer are configured to emit a same color light. ### Claim 13 (depends on 1) The display apparatus of claim 1, wherein the first emission layer and the third emission layer include a blue emission layer. ### Claim 14 (depends on 1) The display apparatus of claim 1, wherein the second emission layer includes one or more of a yellow-green emission layer, a green emission layer, or a yellow-green emission layer and a green emission layer. ### Claim 15 (depends on 1) The display apparatus of claim 1, wherein the second emission layer includes one or more of a red emission layer, a yellow-green emission layer, or a green emission layer, or one of combinations thereof. ### Claim 16 (depends on 1) The display apparatus of claim 1, further comprising: a hole injection layer over the third hole transport layer. ### Claim 17 A display apparatus, comprising: a first electrode and a second electrode over a substrate; a first emission part over the first electrode, the first emission part being between a first charge generation layer and a second charge generation layer; a second emission part over the first emission part, the second emission part being between a third charge generation layer and a fourth charge generation layer; and a third emission part over the second emission part, the third emission part being between a fifth charge generation layer and the second electrode, wherein a thickness of the third emission part is larger than a thickness of the second emission part. ### Claim 18 (depends on 17) The display apparatus of claim 17, wherein the thickness of the third emission part is equal to or smaller than a thickness of the first emission part. ### Claim 19 (depends on 18) The display apparatus of claim 18, wherein the thickness of the second emission part is smaller than a thickness of the first emission part. ### Claim 20 (depends on 17) The display apparatus of claim 17, wherein the first emission part includes a first electron transport layer, a first emission layer, and a first hole transport layer over the first charge generation layer, wherein the second emission part includes a second electron transport layer, a second emission layer, and a second hole transport layer over the third charge generation layer, and wherein the third emission part includes a third electron transport layer, a third emission layer, and a third hole transport layer over the fifth charge generation layer. ### Claim 21 (depends on 20) The display apparatus of claim 20, wherein a thickness of the third electron transport layer is larger than a thickness of the second electron transport layer. ### Claim 22 (depends on 20) The display apparatus of claim 20, wherein a thickness of the third electron transport layer is smaller than a thickness of the first electron transport layer. ### Claim 23 (depends on 20) The display apparatus of claim 20, wherein a sum of the thicknesses of the first charge generation layer and the first electron transport layer is larger than a sum of the thicknesses of the third charge generation layer and the second electron transport layer. ### Claim 24 (depends on 20) The display apparatus of claim 20, wherein a sum of the thicknesses of the third charge generation layer and the second electron transport layer is smaller than a sum of the thicknesses of the fifth charge generation layer and the third electron transport layer. ### Claim 25 (depends on 20) The display apparatus of claim 20, wherein a refractive index of the third electron transport layer is in a range from 1.90 to 2.10, inclusive. ### Claim 26 (depends on 20) The display apparatus of claim 20, wherein at least one or more of the first hole transport layer, the second hole transport layer, or third hole transport layer include two or more hole transport layers. ### Claim 27 (depends on 26) The display apparatus of claim 26, wherein the third hole transport layer includes two or more hole transport layers, and among the two or more hole transport layers of the third hole transport layer, a thickness of a hole transport layer adjacent to the third emission layer is smaller than a thickness of a hole transport layer adjacent to the second electrode. ### Claim 28 (depends on 17) The display apparatus of claim 17, wherein the first electrode is a cathode electrode and the second electrode is an anode electrode.