US-12618004-B2 - Light-emitting element ink and method for manufacturing display apparatus

Abstract

A light-emitting element ink comprises: a light-emitting element solvent; and a plurality of light-emitting elements dispersed in the light-emitting element solvent and each comprising a plurality of semiconductor layers and an insulation film partially around the outer peripheral surfaces of the semiconductor layers, wherein the light-emitting element solvent includes a fatty acid ester-based compound having a melting point in the range of 0° C. to 15° C.

Inventors

• Jae Hoon Jung
• Jong Hyuk KANG
• Hee Yeon YOO
• Hyun Min Cho
• Hye Jung Hong

Assignees

• SAMSUNG DISPLAY CO., LTD.

Dates

Publication Date

20260505

Application Date

20210401

Priority Date

20200424

Claims (6)

1. 1 . A light-emitting element ink comprising: a light-emitting element solvent comprising a compound represented by Chemical Formula 1; and a plurality of light-emitting elements dispersed in the light-emitting element solvent, each the plurality of light-emitting elements comprising a plurality of semiconductor layers and an insulation film partially around outer peripheral surfaces of the plurality of semiconductor layers, wherein the light-emitting element solvent comprises a fatty acid ester-based compound having a melting point in a range of 0° C. to 15° C.; wherein, in Chemical Formula 1, R 1 and R 2 are each independently a linear or branched alkyl group, alkyl ether group, or alkenyl ether group having 1 to 25 carbon atoms, and at least one selected from among R 1 and R 2 in Chemical Formula 1 comprises a functional group represented by Chemical Formula 2: wherein, in Chemical Formula 2, n is in a range of 1 to 4, and a total number of oxygen atoms in Chemical Formula 1 is in a range of 2 to 10.
2. 2 . The light-emitting element ink of claim 1 , wherein a sum of a number of carbon atoms of R 1 and a number of carbon atoms of R 2 is in a range of 14 to 49.
3. 3 . The light-emitting element ink of claim 1 , wherein the light-emitting element solvent comprises a compound represented by one of Chemical Formulae 3 to 6:
4. 4 . The light-emitting element ink of claim 2 , wherein the light-emitting element solvent has a viscosity in a range of 8 cP to 10 cP, which is measured at room temperature.
5. 5 . The light-emitting element ink of claim 2 , wherein the light-emitting element solvent has a dielectric constant in a range of 0.1 to 5.
6. 6 . The light-emitting element ink of claim 2 , wherein the plurality of semiconductor layers of each of the plurality of light-emitting elements comprise a first semiconductor layer, a second semiconductor layer, and a light-emitting layer between the first semiconductor layer and the second semiconductor layer, and the insulation film is around at least an outer surface of the light-emitting layer.

Description

CROSS REFERENCE TO RELATED APPLICATION(S) This application is a U.S. National Phase Patent Application of International Patent Application Number PCT/KR2021/004077, filed on Apr. 1, 2021, which claims priority to Korean Patent Application Number 10-2020-0050110, filed on Apr. 24, 2020, the entire content of all of which is incorporated herein by reference. BACKGROUND 1. Field The disclosure relates to a light-emitting element ink and a method for manufacturing a display apparatus. More particularly, the disclosure relates to a light-emitting element ink including a solvent having a high melting point, and a method for manufacturing a display apparatus using the same. 2. Description of the Related Art The importance of display devices has steadily increased with the development of multimedia technology. In response thereto, various types (or kinds) of display devices such as an organic light emitting display (OLED), a liquid crystal display (LCD) and/or the like have been used. A display device is a device for displaying an image, and includes a display panel, such as an organic light emitting display panel and/or a liquid crystal display panel. The light emitting display panel may include light emitting elements, e.g., light emitting diodes (LED), and examples of the light emitting diode include an organic light emitting diode (OLED) using an organic material as a fluorescent material and an inorganic light emitting diode using an inorganic material as a fluorescent material. SUMMARY The disclosure is directed to providing a light-emitting element ink in which light-emitting elements are not precipitated during storage by including a solvent having a high melting point. The disclosure is also directed to providing a method for manufacturing a display apparatus with improved product reliability by uniformly disposing light-emitting elements per unit area using the light-emitting element ink. It should be noted that aspects of the disclosure are not limited thereto and other aspects, which are not mentioned herein, will be apparent to those of ordinary skill in the art from the following description. According to one or more embodiments of the disclosure, a light-emitting element ink comprises a light-emitting element solvent, and a plurality of light-emitting elements dispersed in the light-emitting element solvent and each including a plurality of semiconductor layers and an insulation film partially surrounding (e.g., being partially around) outer peripheral surfaces of the semiconductor layers, wherein the light-emitting element solvent includes a fatty acid ester-based compound having a melting point in a range of 0° C. to 15° C. The light-emitting element solvent may include a compound represented by Chemical Formula 1 below. wherein, in Chemical Formula 1, R1 and R2 are each independently a linear or branched alkyl group, alkyl ether group, or alkenyl ether group having 1 to 25 carbon atoms, and a sum of the number of carbon atoms of R1 and the number of carbon atoms of R2 is in a range of 14 to 49. At least one of R1 and R2 in Chemical Formula 1 may include a functional group represented by Chemical Formula 2 below. wherein, in Chemical Formula 2, n is in a range of 1 to 4, and a total number of oxygen atoms in Chemical Formula 1 is in a range of 2 to 10. The light-emitting element solvent may include a compound represented by one of Chemical Formulas 3 to 6 below. The light-emitting element solvent may have a viscosity in a range of 8 cP to 10 cP, which is measured at room temperature. The light-emitting element solvent may have a dielectric constant in a range of 0.1 to 5. The semiconductor layers of the light-emitting element may include a first semiconductor layer, a second semiconductor layer, and a light-emitting layer provided between the first semiconductor layer and the second semiconductor layer, and the insulation film may be provided to surround (e.g., be around) at least an outer peripheral surface of the light-emitting layer. According to one or more embodiments of the disclosure, a method for manufacturing a display apparatus, the method comprises preparing a light-emitting element ink including a light-emitting element solvent and a plurality of light-emitting elements dispersed in the light-emitting element solvent, and a target substrate on which a first electrode and a second electrode are formed, spraying the light-emitting element ink onto the target substrate at a temperature greater than or equal to a melting point of the light-emitting element solvent, and seating each of the light-emitting elements on the first electrode and the second electrode by generating an electric field on the target substrate. Each of the light-emitting elements may include a plurality of semiconductor layers and an insulation film partially surrounding (e.g., partially around) outer peripheral surfaces of the semiconductor layers, and the light-emitting element solvent may include an ester group and i