Double-sub-single-layer OLED device with different middle spacing layers

Abstract

The utility model relates to a double-sub-single-layer OLED device with different middle spacing layers. The double-sub-single-layer OLED device comprises an ITO anode, an m-MTDATA hole injection layer, a C545T light-emitting layer, an NPB hole transport layer or an Alq hole transport layer, a DCM2 light-emitting layer, an Alq electron transport layer and an aluminum and lithium fluoride composite cathode which are arranged in sequence. The C545T light-emitting layer and the DCM2 light-emitting layer are both of a sub-single-layer structure. The OLED device overcomes the defect of quenching caused by high doping concentration in the traditional process, also avoids the defect that the doping concentration is low and is difficult to control, has a simple structure, is easy and convenient to manufacture, and can be widely applied to preparation of OLED devices.

Description

Technical Field

[0001] This utility model relates to the field of organic light-emitting device technology, and in particular to a dual sub-single-layer OLED device with different intermediate spacers. Background Technology

[0002] Organic light-emitting diodes (OLEDs) emit light by injecting holes and electrons into the anode and cathode of the device, respectively. These electrons meet in the light-emitting region, forming excitons, which then de-excite and emit light. With the needs of social development, people are paying increasing attention to lighting safety. Even under normal lighting conditions, a significant amount of blue light is emitted, which can prevent people from getting quality rest. Furthermore, short-wavelength blue light can oxidize cells in the macular region of the retina. The lens of the still-developing human eye has a very high transmittance of short-wavelength spectral radiation, several times that of a fully developed eye. Therefore, the risk of blue light exposure is extremely high for infants and young children.

[0003] Therefore, it is essential to develop safe lighting sources with low blue light emission. Organic light-emitting diodes (OLEDs) can easily control the emission color and intensity by controlling the growth thickness of different light-emitting materials. Therefore, this invention proposes an OLED device using yellow and green light-emitting materials; since no blue light-emitting materials are used, the emission intensity is very weak, thus the device is very safe. In particular, yellow organic light-emitting diodes, due to their spectrum containing no or only a small amount of ultraviolet components, are widely used in yellow light zones of electronics factories, museums, art galleries, archives, libraries, art galleries, high-end boutiques, color matching of printed materials, and antique storage facilities.

[0004] However, current methods for fabricating yellow OLEDs generally employ a structure where a guest red fluorescent dye is doped with a green organic electroluminescent material. Because the high-efficiency luminescent material exhibits a strong concentration quenching effect, the doping concentration of the luminescent material is typically required to be very low to obtain high-performance devices. However, using a co-evaporation process makes it difficult to control the low doping concentration ratio, resulting in poor reproducibility of the fabricated devices.

[0005] In view of this, the present invention proposes a dual sub-single-layer OLED device with different intermediate spacers. Utility Model Content

[0006] The purpose of this invention is to provide a dual-sub-monolayer OLED device with different intermediate spacers, which overcomes the disadvantage of quenching caused by high doping concentration in traditional processes. It has a simple structure, is easy to manufacture, and can be widely used in the preparation of OLED devices.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows:

[0008] This invention proposes a dual sub-monolayer OLED device with different intermediate spacers, comprising an ITO anode, an m-MTDATA hole injection layer, a C545T light-emitting layer, an NPB hole transport layer, a DCM2 light-emitting layer, an Alq electron transport layer, and a composite cathode of aluminum and lithium fluoride arranged sequentially; both the C545T light-emitting layer and the DCM2 light-emitting layer adopt a sub-monolayer structure.

[0009] The present invention also proposes a dual sub-monolayer OLED device with different intermediate spacers, comprising an ITO anode, an m-MTDATA hole injection layer, a C545T light-emitting layer, an Alq hole transport layer, a DCM2 light-emitting layer, an Alq electron transport layer, and a composite cathode of aluminum and lithium fluoride arranged sequentially; both the C545T light-emitting layer and the DCM2 light-emitting layer adopt a sub-monolayer structure.

[0010] Preferably, the thickness of the m-MTDATA hole injection layer is 40 nm.

[0011] Preferably, the thickness of the C545T light-emitting layer is 0.025 nm.

[0012] Preferably, the thickness of the NPB hole transport layer or the Alq hole transport layer is 5 nm.

[0013] Preferably, the thickness of the DCM2 light-emitting layer is 0.05 nm.

[0014] Preferably, the thickness of the Alq electron transport layer is 50 nm.

[0015] Preferably, in the composite cathode of aluminum and lithium fluoride, the thickness of aluminum is 200 nm and the thickness of lithium fluoride is 0.5 nm.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The technical solution adopted in this invention can obtain yellow light with good performance and has the advantages of simple structure. At the same time, it avoids the disadvantage of low doping concentration being difficult to control, making it easier to implement in terms of process and widely applicable to the fields of lighting and display. Attached Figure Description

[0018] Figure 1 This is a structural diagram of the utility model. Detailed Implementation

[0019] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings.

[0020] This invention discloses a dual-sub-monolayer OLED device with different intermediate spacers, comprising, sequentially arranged, an indium tin oxide (ITO) transparent conductive film glass anode, a 4,4',4''-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) hole injection layer, a C545T light-emitting layer, and an N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB) or 8-hydroxyquinoline aluminum. The structure comprises a hole transport layer of (Alq), a 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyran[6,7,8-ij]quinolineazine-11-one (DCM2) luminescent layer, an 8-hydroxyquinoline aluminum (Alq) electron transport layer, and a composite cathode of aluminum (Al) and lithium fluoride (LiF); both the C545T luminescent layer and the DCM2 luminescent layer adopt a sub-monolayer structure.

[0021] In this embodiment, the thickness of the m-MTDATA hole injection layer is 40 nm.

[0022] In this embodiment, the thickness of the C545T light-emitting layer is 0.025 nm.

[0023] In this embodiment, the thickness of the NPB hole transport layer or the Alq hole transport layer is 5 nm.

[0024] In this embodiment, the thickness of the DCM2 light-emitting layer is 0.05 nm.

[0025] In this embodiment, the thickness of the Alq electron transport layer is 50 nm.

[0026] In this embodiment, in the composite cathode of aluminum and lithium fluoride, the thickness of aluminum is 200 nm and the thickness of lithium fluoride is 0.5 nm.

[0027] The fabrication process and working principle of the dual sub-monolayer OLED device are as follows:

[0028] Device 1 is formed by sequentially depositing m-MTDATA, C545T, NPB, DCM2, Alq, LiF, and Al on an ITO thin film using vapor deposition and sub-monolayer organic light-emitting technology, or device 2 is formed by depositing m-MTDATA, C545T, Alq, DCM2, Alq, LiF, and Al on an ITO thin film.

[0029] By inserting NPB or Alq between the sub-monolayer organic light-emitting materials C545T and DCM2, electrons and holes are injected from the cathode and anode, respectively. Under the influence of an electric field, excitons are formed between the two sub-monolayers, enabling the light emission of different material molecules. Due to the thin sub-monolayer structure, the DCM2 light-emitting layer emits relatively high-performance yellow light (the emission spectrum gradually red-shifts as the DCM2 thickness increases). Furthermore, in device 1, the hole-transporting material NPB blocks electron transport, resulting in a low number of excitons in C545T and thus weak green light. In device 2, the hole-transporting material Alq strongly transports electrons, therefore, C545T, DCM2, and Alq all emit light.

[0030] The above are preferred embodiments of this utility model. Any changes made to the technical solution of this utility model that do not exceed the scope of the technical solution of this utility model shall be protected within the scope of this utility model.

Claims

1. A dual-sub-monolayer OLED device with different intermediate spacers, characterized in that, It includes an ITO anode, an m-MTDATA hole injection layer, a C545T light-emitting layer, an NPB hole transport layer, a DCM2 light-emitting layer, an Alq electron transport layer, and a composite cathode of aluminum and lithium fluoride arranged in sequence; the C545T light-emitting layer and the DCM2 light-emitting layer both adopt a sub-monolayer structure.

2. A dual-sub-monolayer OLED device with different intermediate spacers, characterized in that, It includes an ITO anode, an m-MTDATA hole injection layer, a C545T light-emitting layer, an Alq hole transport layer, a DCM2 light-emitting layer, an Alq electron transport layer, and a composite cathode of aluminum and lithium fluoride arranged in sequence; the C545T light-emitting layer and the DCM2 light-emitting layer both adopt a sub-monolayer structure.

3. A dual-sub-monolayer OLED device with different intermediate spacers according to claim 1 or 2, characterized in that, The thickness of the m-MTDATA hole injection layer is 30nm-60nm.

4. A dual-sub-monolayer OLED device with different intermediate spacers according to claim 1 or 2, characterized in that, The thickness of the C545T light-emitting layer is 0.025nm-0.1nm.

5. A dual-sub-monolayer OLED device with different intermediate spacers according to claim 1 or 2, characterized in that, The thickness of the NPB hole transport layer or the Alq hole transport layer is 5nm-10nm.

6. A dual-sub-monolayer OLED device with different intermediate spacers according to claim 1 or 2, characterized in that, The thickness of the DCM2 luminescent layer is 0.05nm-0.1nm.

7. A dual-sub-monolayer OLED device with different intermediate spacers according to claim 1 or 2, characterized in that, The thickness of the Alq electron transport layer is 30nm-60nm.

8. A dual-sub-monolayer OLED device with different intermediate spacers according to claim 1 or 2, characterized in that, In the composite cathode of aluminum and lithium fluoride, the thickness of aluminum is 100nm-300nm and the thickness of lithium fluoride is 0.5nm-1.5nm.

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