# US 10,373,559 B2 · Organic light-emitting device and organic light-emitting display device using the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,373,559 B2 - Document ID: US10373559B2 - Status: Granted - Kind: B2 - Application number: 15/838,887 - Filed: 2017-12-12 - Published: 2018-07-05 - Granted: 2019-08-06 - Earliest claimed: 2016-12-30 - Assignees: LG Display Co., Ltd. - Applicants: LG Display Co., Ltd. - Inventors: Seok-Hyun Kim; Eun-Jung Park; Ho-Sung Kim - Web page: https://patentgrep.com/patent/US10373559B2 ## CPC - G09G 3/3225: using an active matrix - G09G 3/3216: using a passive matrix - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/3291: in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements - H10K 50/131: {with spacer layers between the electroluminescent layers} - H10K 50/19: Tandem OLEDs - H10K 59/1216: {the pixel elements being capacitors} - H10K 59/32: Stacked devices having two or more layers, each emitting at different wavelengths - H10K 59/35: comprising red-green-blue [RGB] subpixels - H10K 59/80518: {Reflective anodes, e.g. ITO combined with thick metallic layers} - H10K 59/876: {comprising a resonant cavity structure, e.g. Bragg reflector pair} - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract An organic light-emitting device and an organic light-emitting display device using the same are discussed. In a structure in which emission layers that emit light having the same color are provided in a plurality of stacks, the emission layers have different properties such that the light emission efficiencies of the stacks are made uniform, whereby the lifespan of the organic light-emitting device is increased through charge balance. ## Claims ### Claim 1 An organic light-emitting device comprising: a first electrode and a second electrode provided opposite each other; a charge generation layer provided between the first electrode and the second electrode; a first stack provided between the first electrode and the charge generation layer, the first stack comprising a first hole transport layer, a first emission layer, and a first electron transport layer; and a second stack provided between the charge generation layer and the second electrode, the second stack comprising a second hole transport layer, a second emission layer, which emits a same color as the first emission layer, and a second electron transport layer, wherein a hole transport rate of the second emission layer is higher than a hole transport rate of the first emission layer so that an emission zone of the second emission layer is maintained without movement towards the charge generation layer over time. ### Claim 2 (depends on 1) The organic light-emitting device according to claim 1, wherein: the first emission layer and the second emission layer have a first bipolar host and a second bipolar host, respectively, and hole mobility of the second host is higher than hole mobility of the first host, or a highest occupied molecular orbital (HOMO) energy level of the second host is lower than a HOMO energy level of the first host. ### Claim 3 (depends on 2) The organic light-emitting device according to claim 2, wherein an electron mobility of the second host is higher than an electron mobility of the first host. ### Claim 4 (depends on 1) The organic light-emitting device according to claim 1, wherein: the first emission layer has a first hole transport host and a first electron transport host, and the second emission layer has a second hole transport host and a second electron transport host. ### Claim 5 (depends on 4) The organic light-emitting device according to claim 4, wherein: an electron transport rate of the first emission layer is higher than an electron transport rate of the second emission layer, and a hole transport rate of the second emission layer is higher than a hole transport rate of the first emission layer. ### Claim 6 (depends on 5) The organic light-emitting device according to claim 5, wherein: an amount of the second hole transport host in the second emission layer is greater than an amount of the first hole transport host in the first emission layer, and an amount of the first electron transport host in the first emission layer is greater than an amount of the second electron transport host in the second emission layer. ### Claim 7 (depends on 4) The organic light-emitting device according to claim 4, wherein: a hole mobility of the first hole transport host is at least 10 times higher than a hole mobility of the first electron transport host, and an electron mobility of the first electron transport host is at least 10 times higher than an electron mobility of the first hole transport host. ### Claim 8 (depends on 7) The organic light-emitting device according to claim 7, wherein: a hole mobility of the second hole transport host is at least 10 times higher than hole mobility of the second electron transport host, and an electron mobility of the second electron transport host is at least 10 times higher than electron mobility of the second hole transport host. ### Claim 9 (depends on 4) The organic light-emitting device according to claim 4, wherein: a hole mobility of the second hole transport host is higher than a hole mobility of the first hole transport host, and an electron mobility of the first electron transport host is higher than an electron mobility of the second electron transport host. ### Claim 10 An organic light-emitting display device comprising: a substrate having a plurality of sub-pixels; a thin film transistor provided at at least one of the sub-pixels on the substrate; and an organic light-emitting device connected to the thin film transistor, wherein the organic light-emitting device comprises: a first electrode and a second electrode opposite each other; a charge generation layer provided between the first electrode and the second electrode; a first stack provided between the first electrode and the charge generation layer, the first stack comprising a first hole transport layer, a first emission layer, and a first electron transport layer; and a second stack provided between the charge generation layer and the second electrode, the second stack comprising a second hole transport layer, a second emission layer, which emits a same color as the first emission layer, and a second electron transport layer, and wherein a hole transport rate of the second emission layer is higher than a hole transport rate of the first emission layer so that an emission zone of the second emission layer is maintained without movement towards the charge generation layer over time. ### Claim 11 (depends on 10) The organic light-emitting device according to claim 10, wherein a highest occupied molecular orbital (HOMO) energy level of a second host in the second emission layer is lower than a HOMO energy level of a first host of the first emission layer. ### Claim 12 (depends on 11) The organic light-emitting device according to claim 11, wherein an electron mobility of the second host is higher than an electron mobility of the first host. ### Claim 13 An organic light-emitting device comprising: a first electrode and a second electrode provided opposite each other; a charge generation layer provided between the first electrode and the second electrode; a first stack provided between the first electrode and the charge generation layer, the first stack comprising a first hole transport layer, a first emission layer, and a first electron transport layer; and a second stack provided between the charge generation layer and the second electrode, the second stack comprising a second hole transport layer, a second emission layer, which emits a same color as the first emission layer, and a second electron transport layer, wherein a hole transport rate of the second emission layer is higher than a hole transport rate of the first emission layer, and wherein an electron transport rate of the first emission layer is higher than an electron transport rate of the second emission layer.