# US 12,604,629 B2 · Display panel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,604,629 B2 - Document ID: US12604629B2 - Status: Granted - Kind: B2 - Application number: 17/781,109 - Filed: 2022-05-26 - Published: 2024-06-06 - Granted: 2026-04-14 - Earliest claimed: 2022-04-29 - Assignees: Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. - Applicants: Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. - Inventors: Guoqi Xia; Mugyeom Kim - Web page: https://patentgrep.com/patent/US12604629B2 ## CPC - H10K 59/32: Stacked devices having two or more layers, each emitting at different wavelengths - H10K 50/00: Organic light-emitting devices (integrated devices or assemblies of multiple devices H10K59/00, H10K65/00; organic semiconductor lasers H01S5/36) - H10K 50/11: characterised by the electroluminescent [EL] layers - H10K 50/13: comprising stacked EL layers within one EL unit - H10K 50/19: Tandem OLEDs - H10K 2101/00: Properties of the organic materials covered by group H10K85/00 - H10K 2101/30: Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values - H10K 2101/40: Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers - H10K 2102/351: {Thickness} - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract The present application discloses a display panel, and a light-emitting functional layer of the display panel. The light-emitting functional layer includes a first light-emitting layer and a second light-emitting layer. The first light-emitting layer includes a first light-emitting sublayer. The second light-emitting layer includes a second light-emitting sublayer. The first light-emitting sublayer has a first film compactness parameter, and the first film compactness parameter is greater than or equal to a first threshold. The second light-emitting sublayer has a second film compactness parameter, and the second film compactness parameter is greater than or equal to a second threshold. The first film compactness parameter and the second film compactness parameter are determined by an amount of change of the film under a unit force condition. ## Claims ### Claim 1 A display panel, comprising: a substrate; a first electrode provided on the substrate; and a light-emitting functional layer arranged on a side of the first electrode away from the substrate, wherein the light-emitting functional layer comprises a first light-emitting layer, a charge generation layer, and a second light-emitting layer sequentially arranged on the first electrode, the first light-emitting layer comprises a first light-emitting sublayer, and the second light-emitting layer comprises a second light-emitting sublayer; and a second electrode arranged on a side of the second light-emitting layer away from the charge generation layer; wherein the first light-emitting sublayer has a first film compactness parameter, the first film compactness parameter is greater than or equal to a first threshold, the second light-emitting sublayer has a second film compactness parameter, and the second film compactness parameter is greater than or equal to a second threshold, and the first film compactness parameter and the second film compactness parameter are determined by an amount of change generated by the film under a unit force condition; wherein the first film compactness parameter is calculated by the following formula: X1=ΔF1/ΔH1; wherein ΔF1 is a difference of different forces in a thickness direction of a film; ΔH1 is a thickness difference of a stressed portion of the film under the different forces; and the second film compactness parameter is calculated by the following formula: X2=ΔF2/ΔH2; wherein ΔF2 is a difference of different forces in a thickness direction of a film; ΔH2 is a thickness difference of a stressed portion of the film under the different forces; wherein the first threshold is −1.7, and the first film compactness parameter is less than 0; and the second threshold is −1.7, and the second film compactness parameter is less than 0; wherein the first light-emitting layer comprises a first hole injection sublayer, a first hole transport sublayer, the first light-emitting sublayer, a first electron transport sublayer, and a first electron injection sublayer stacked sequentially; and the second light-emitting layer comprises a second hole injection sublayer, a second hole transport sublayer, the second light-emitting sublayer, a second electron transport sublayer, and a second electron injection sublayer stacked sequentially; wherein the charge generation layer comprises a first charge generation layer and a second charge generation layer, the first charge generation layer is arranged on a side of the first light-emitting layer away from the first electrode, the first charge generation layer comprises an n-type charge generation material, the second charge generation layer is arranged on a side of the first charge generation layer away from the first light-emitting layer, and the second charge generation layer comprises a p-type charge generation material; wherein the n-type charge generation material comprises TPBi doped with 5% Yb, and a thickness of the first charge generation layer is 100 nm; the p-type charge generation material comprises NPB doped with 5% HATCN, and a thickness of the second charge generation layer is 100 nm; wherein the first light-emitting sublayer is doped with an organic light-emitting material with a dosage concentration being less than 2%, and a thickness of the first light-emitting sublayer ranges from 10 nm to 30 nm; the second light-emitting sublayer is doped with an organic light-emitting material with a dosage concentration being less than 2%, and a thickness of the second light-emitting sublayer ranges from 10 nm to 30 nm; and wherein the second electrode is doped with Mg with a dosage concentration being 9%, and a thickness of the second electrode ranges from 10 nm to 50 nm. ### Claim 2 (depends on 1) The display panel of claim 1, wherein the first film compactness parameter and the second film compactness parameter are determined by the thickness shape variable generated by the stressed portion of the film under the unit force condition in the thickness direction of the film. ### Claim 3 (depends on 1) The display panel of claim 1, wherein, when the display panel is powered on, a ratio between a dimensional deformation degree of the light-emitting function layer and an original shape and dimension of the light-emitting function layer is less than or equal to 7.5%. ### Claim 4 (depends on 3) The display panel of claim 3, wherein, when the display panel is powered on, a ratio between a thickness expansion degree of the light-emitting functional layer and an original thickness of the light-emitting functional layer is less than or equal to 7.5%. ### Claim 5 (depends on 1) The display panel of claim 1, wherein, when the display panel is heated, a ratio between a dimensional deformation degree of the light-emitting function layer and an original shape and dimension of the light-emitting function layer is less than or equal to 13%. ### Claim 6 (depends on 5) The display panel of claim 5, wherein, when the display panel is heated, a ratio between a thickness expansion degree of the light-emitting functional layer and an original thickness of the light-emitting functional layer is less than or equal to 13%. ### Claim 7 (depends on 1) The display panel of claim 1, wherein energy levels of highest occupied molecular orbitals and lowest unoccupied molecular orbitals of the first hole transport sublayer, the first light-emitting sublayer, and the first electron transport sublayer are decreased sequentially, and energy levels of highest occupied molecular orbitals and lowest unoccupied molecular orbitals of the second hole transport sublayer, the second light-emitting sublayer and the second electron transport sublayer are decreased sequentially. ### Claim 8 (depends on 7) The display panel of claim 7, wherein an energy level difference between the highest occupied molecular orbitals of the first hole transport sublayer and the first light-emitting sublayer is less than or equal to 0.2 eV, and an energy level difference between the lowest unoccupied molecular orbital of the first electron transport sublayer and the first light-emitting sublayer is less than or equal to 0.2 eV; and an energy level difference between the highest occupied molecular orbitals of the second hole transport sublayer and the second light-emitting sublayer is less than or equal to 0.2 eV, and an energy level difference between the lowest unoccupied molecular orbitals of the second electron transport sublayer and the second light-emitting sublayer is less than or equal to 0.2 eV. ### Claim 9 (depends on 1) The display panel of claim 1, wherein the first light-emitting sublayer comprises a blue phosphorescent light-emitting material or a blue fluorescent light-emitting material, and the second light-emitting sublayer comprises a blue phosphorescent light-emitting material or a blue fluorescent light-emitting material. ### Claim 10 (depends on 1) The display panel of claim 1, wherein the first light-emitting sublayer and the second light-emitting sublayer comprise a red phosphorescent light-emitting material or a red fluorescent light-emitting material. ### Claim 11 (depends on 1) The display panel of claim 1, wherein the first light-emitting sublayer and the second light-emitting sublayer comprise a green phosphorescent light-emitting material or a green fluorescent light-emitting material. ### Claim 12 (depends on 1) The display panel of claim 1, wherein the first electrode is an anode and the second electrode is a cathode. ### Claim 13 A display panel comprising: a substrate; a first electrode provided on the substrate; a light-emitting functional layer arranged on a side of the first electrode away from the substrate, wherein the light-emitting functional layer comprises a first light-emitting layer, a charge generation layer, and a second light-emitting layer sequentially arranged on the first electrode, the first light-emitting layer comprises a first light-emitting sublayer, and the second light-emitting layer comprises a second light-emitting sublayer; and a second electrode arranged on a side of the second light-emitting layer away from the charge generation layer; wherein the first light-emitting sublayer has a first film compactness parameter, the first film compactness parameter is greater than or equal to a first threshold, the second light-emitting sublayer has a second film compactness parameter, and the second film compactness parameter is greater than or equal to a second threshold, and the first film compactness parameter and the second film compactness parameter are determined by an amount of change generated by the film under a unit force condition, and wherein the first film compactness parameter and the second film compactness parameter are characterized by atomic force microscopy; wherein the first film compactness parameter is calculated by the following formula: X1=ΔF1/ΔH1; wherein ΔF1 is a difference of different forces in a thickness direction of a film; ΔH1 is a thickness difference of a stressed portion of the film under the different forces; and the second film compactness parameter is calculated by the following formula: X2=ΔF2/ΔH2; wherein ΔF2 is a difference of different forces in a thickness direction of a film; ΔH2 is a thickness difference of a stressed portion of the film under the different forces; wherein the first threshold is −1.7, and the first film compactness parameter is less than 0; and the second threshold is −1.7, and the second film compactness parameter is less than 0; wherein the first light-emitting layer comprises a first hole injection sublayer, a first hole transport sublayer, the first light-emitting sublayer, a first electron transport sublayer, and a first electron injection sublayer stacked sequentially; and the second light-emitting layer comprises a second hole injection sublayer, a second hole transport sublayer, the second light-emitting sublayer, a second electron transport sublayer, and a second electron injection sublayer stacked sequentially; and wherein the first light-emitting sublayer is doped with an organic light-emitting material with a dosage concentration being less than 2%, and a thickness of the first light-emitting sublayer ranges from 10 nm to 30 nm; the second light-emitting sublayer is doped with an organic light-emitting material with a dosage concentration being less than 2%, and a thickness of the second light-emitting sublayer ranges from 10 nm to 30 nm. ### Claim 14 (depends on 13) The display panel of claim 13, wherein the first film compactness parameter and the second film compactness parameter are determined by the thickness shape variable generated by the stressed portion of the film under the unit force condition in the thickness direction of the film. ### Claim 15 A display panel, comprising: a substrate; a first electrode provided on the substrate; and a light-emitting functional layer arranged on a side of the first electrode away from the substrate, wherein the light-emitting functional layer comprises a first light-emitting layer, a charge generation layer, and a second light-emitting layer sequentially arranged on the first electrode, the first light-emitting layer comprises a first light-emitting sublayer, and the second light-emitting layer comprises a second light-emitting sublayer; and a second electrode arranged on a side of the second light-emitting layer away from the charge generation layer; wherein the first light-emitting layer comprises a first hole injection sublayer, a first hole transport sublayer, the first light-emitting sublayer, a first electron transport sublayer, and a first electron injection sublayer stacked sequentially; and the second light-emitting layer comprises a second hole injection sublayer, a second hole transport sublayer, the second light-emitting sublayer, a second electron transport sublayer, and a second electron injection sublayer stacked sequentially; wherein the charge generation layer comprises a first charge generation layer and a second charge generation layer, the first charge generation layer is arranged on a side of the first light-emitting layer away from the first electrode, the first charge generation layer comprises an n-type charge generation material, the second charge generation layer is arranged on a side of the first charge generation layer away from the first light-emitting layer, and the second charge generation layer comprises a p-type charge generation material; wherein the n-type charge generation material comprises TPBi doped with 5% Yb, and a thickness of the first charge generation layer is 100 nm; the p-type charge generation material comprises NPB doped with 5% HATCN, and a thickness of the second charge generation layer is 100 nm; wherein the first light-emitting sublayer is doped with an organic light-emitting material with a dosage concentration being less than 2%, and a thickness of the first light-emitting sublayer ranges from 10 nm to 30 nm; the second light-emitting sublayer is doped with an organic light-emitting material with a dosage concentration being less than 2%, and a thickness of the second light-emitting sublayer ranges from 10 nm to 30 nm; and wherein the second electrode is doped with Mg with a dosage concentration being 9%, and a thickness of the second electrode ranges from 10 nm to 50 nm.