KR-20260063842-A - Light-emitting diodes and Method of manufacturing for the same

Abstract

A light-emitting element according to various embodiments of the present invention comprises: a first electrode and a second electrode facing each other; a light-emitting layer located between the first electrode and the second electrode and including a perovskite; and an interface modification layer disposed on the light-emitting layer, wherein the interface modification layer can change the crystal structure of the perovskite. A method for manufacturing a light-emitting device according to various embodiments of the present invention comprises the steps of: preparing a substrate having a second electrode formed thereon; forming a hole transport layer on the second electrode; forming an interface modification layer on the hole transport layer; and forming a light-emitting layer on the interface modification layer, wherein the step of forming the light-emitting layer may be carried out by a vacuum thermal evaporation method.

Inventors

• 이준형
• 보반코에
• 임효준
• 이나윤
• 당티흐엉타오
• 허영우

Assignees

• 경북대학교 산학협력단

Dates

Publication Date

20260507

Application Date

20241031

Claims (13)

1. First electrode and second electrode facing each other; A light-emitting layer located between the first electrode and the second electrode and comprising perovskite; and Includes an interface modification layer disposed on the light-emitting layer; The above interface modification layer is a light-emitting device that changes the crystal structure of the above perovskite.
2. In paragraph 1, The above interface modification layer comprises a material containing four long octyl chains symmetrically arranged around a nitrogen atom, in a light-emitting device.
3. In paragraph 1, The above interface modification layer is a light-emitting device comprising tetraoctylammonium bromide (TOABr).
4. In paragraph 1, A light-emitting device comprising the above perovskite being an organic-inorganic hybrid perovskite.
5. In paragraph 1, The above perovskite is a light-emitting device comprising at least one crystal plane among (101), (121) and (202).
6. In paragraph 1, A hole transport layer is included between the second electrode and the light-emitting layer, and The above hole transport layer is a light-emitting device comprising Li-doped NiO.
7. Step of preparing a substrate on which a second electrode is formed; A step of forming a hole transport layer on the second electrode; A step of forming an interface modification layer on the hole transport layer above; and The method includes the step of forming a light-emitting layer on the interface modification layer, and A method for manufacturing a light-emitting device characterized in that the step of forming the light-emitting layer is carried out by a vacuum thermal evaporation method.
8. In Paragraph 7, The step of forming the above interface modification layer is, A method for manufacturing a light-emitting device by spin-coating a solution containing a solvent and an interface-modifying compound.
9. In paragraph 8, A method for manufacturing a light-emitting device in which the above-mentioned interface-modifying compound is a material comprising four long octyl chains symmetrically arranged around a nitrogen atom.
10. In paragraph 8, A method for manufacturing a light-emitting device in which the above-mentioned interface-modifying compound is tetraoctylammonium bromide (TOABr).
11. In paragraph 8, A method for manufacturing a light-emitting device in which the concentration of the interface-modifying compound in the above solution is 0.5 to 5 mg/mL.
12. In Paragraph 7, The step of forming the above-mentioned hole transport layer is, Method for manufacturing a light-emitting device by sputtering Li-doped NiO.
13. In Paragraph 7, The step of forming the light-emitting layer above is, Method for manufacturing a light-emitting device using CsBr and PbBr 2 sources.

Description

Light-emitting diodes and Method of manufacturing for the same Various embodiments of the present invention relate to a light-emitting device and a method for manufacturing the same, and more specifically, to a perovskite light-emitting device comprising an interface modification layer and a method for manufacturing the same. The current display market is trending toward realizing high color purity natural colors. Accordingly, there has been rapid development in organic light-emitting diodes (OLEDs) based on organic light-emitting materials, but there are disadvantages such as the low charge mobility of the organic semiconductor itself, low color purity, and high manufacturing costs of the light-emitting material. Organic-inorganic hybrid perovskite-based solar cells have demonstrated power conversion efficiencies (PCEs) exceeding 20% (laboratory standards) within a few years of their introduction. This success is attributed to the properties of perovskite materials, such as their unprecedentedly high absorbance and low-cost solution processability. Since most of these materials possess characteristics suitable for light-emitting diodes (LEDs), research on perovskite light-emitting diodes (PeLEDs) is being conducted as an alternative to overcome the shortcomings of the aforementioned OLEDs. However, PeLEDs face challenges such as reduced luminous efficiency due to low surface uniformity and difficulties in depositing organic halides used as light-emitting precursors, necessitating research to overcome these issues. FIG. 1 is a cross-sectional view of a light-emitting element according to one embodiment of the present invention. Figure 2(a) shows the XRD pattern of CsPbBr3 deposited on TOABr with a concentration in the range of 0 to 3 mg/mL, (b) shows the preferred peak orientation from (020) to (101), (d) shows the preferred peak orientation from (040) to (202), (c) shows the (121) plane at about 21.5° at TOABr concentrations in the range of 0 to 3 mg/mL deposited on glass, and (e) is a schematic diagram to show that the crystal plane in CsPbBr3 is converted from (020) to (101) due to the addition of TOABr. Figure 3 shows XPS spectra obtained from CsPbBr3 at TOABr concentrations of 0, 1, and 3 mg/mL, with (a) Cs3d, (b) Pb4f, (c) Br3d, and (d) N1s XPS spectra. Figure 4 shows the high-resolution X-ray photoelectron spectroscopy results of Ni 2p 3/2 on ITO/NiLiOx with and without a TOABr layer. Figure 5(a) is the ultraviolet-visible spectrum of CsPbBr3 deposited on glass with a TOABr concentration in the range of 0 to 3 mg/mL, (b) is the PL spectrum with an inset of a film with a TOABr layer (right) and a film without a TOABr layer (left), and (c) is the TRPL spectrum. Figure 6(a) is the total PL spectrum of CsPbBr3 using different HTLs with and without a TOABr layer, (b) is the PL spectrum of ITO/NiLiOx/ CsPbBr3 and ITO/NiLiOx/TOABr/ CsPbBr3 , (c) is the PL spectrum of ITO/PEDOT:PSS/ CsPbBr3 and ITO/PEDOT:PSS/TOAr/CsPbBr3, and ( d ) is the PL spectrum of ITO/PEDOT:PSS/TOABr/ CsPbBr3 and This is the PL spectrum of ITO/NiLiOx/TOABr/CsPbBr 3 . Figure 7 (a) shows the current density-voltage (JV) characteristics of ITO/NiLiOx/HOD (hole-only devices) in the case without TOABr/ CsPbBr3 /Au and (b) in the case with TOABr/ CsPbBr3 /Au. FIG. 8 (a) is a schematic diagram showing the structure of a light-emitting device according to an example, (b) shows a band diagram, (c) shows the JV characteristics of a PeLED with a TOABr concentration in the range of 0 to 3 mg/mL, (d) shows the EQE, (e) shows the LV characteristics, and (f) shows the EL of a PeLED when the TOABr concentration is 1 mg/mL. Hereinafter, various embodiments of this document are described with reference to the accompanying drawings. The embodiments and the terms used therein are not intended to limit the technology described in this document to specific embodiments and should be understood to include various modifications, equivalents, and/or substitutions of said embodiments. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In this specification, "luminescent device" refers to a device that emits light by releasing energy through excitons formed by the combination of holes and electrons in a light-emitting layer located between an anode and a cathode. A light-emitting device according to one embodiment of the present invention may include a first electrode, an electron transfer layer (ETL), an emission material layer (EML), an interface modification layer, a hole transfer layer (HTL), and a second electrode. The first electrode and the second electrode may be positioned facing each other. The first electrode may be an anode electrode and the second electrode may be a cathode electrode, but conversely, the first electrode may be a cathode electrode and the second electrode may be an anode electrode. The first electrode and the second electrode may each be formed of a transparent conduc