CN100508243C

CN100508243C - OLED device with red light

Info

Publication number: CN100508243C
Application number: CNB2006101235584A
Authority: CN
Inventors: 柯贤军; 邝颂贤
Original assignee: Truly Semiconductors Ltd
Current assignee: Truly Semiconductors Ltd
Priority date: 2006-11-15
Filing date: 2006-11-15
Publication date: 2009-07-01
Anticipated expiration: 2026-11-15
Also published as: CN1964097A

Abstract

The disclosed red OLED comprises a substrate and an anode. Wherein, from bottom to top, there is a whole injection layer, a whole transport layer, a red light layer, an electron transport layer, an electron injection layer, a cathode layer, and an embedded layer between the luminescent layer and hole transport layer or electron transport layer. This invention improves device efficiency greatly.

Description

The OLED device that glows

Technical field

The present invention relates to a kind of organic elctroluminescent device OLED, especially relate to a kind of OLED device that glows.

Background technology

Organic electroluminescence device (being that organic light emitting diode is called for short OLED) structure comprises substrate, anode, negative electrode, between anode and negative electrode various function organic/inorganic layers, include but not limited to empty implanted layer (HIL), cavity transport layer (HTL), luminescent layer (EML), electron transfer layer (ETL), electron injecting layer (EIL).In order to improve usefulness, the structure of luminescent layer is main body/object doped system often, promptly utilizes principle that energy shifts that the organic light emission dyestuff is mixed and makes organic light emission dyestuff stimulated luminescence in the organic light emission main body.

The extensive way of OLED device luminescent layer that glows at present is to adopt the single method of mixing of two main bodys, concrete structure is: ITO/2TNATA:F4TCNQ (3%, 100nm)/and NPB (20nm)/Alq3+rubrene:red dopant (2%, 50nm)/BPhen (20nm)/LiF (1nm)/Al (150nm).But be subjected to the restriction of material, the luminous efficiency of red device does not all improve a lot always, the highest can the reaching about 6CD/A of present red device efficiency.

Goal of the invention

The object of the present invention is to provide a kind of red OLED device that can improve luminous efficiency.

Above-mentioned purpose can realize by following technical measures: a kind of OLED device that glows, comprise substrate, anode, place hole injection layer on the anode, place hole transmission layer on the hole injection layer, place rubescent photosphere on the hole transmission layer, place electron transfer layer on the rubescent photosphere, place electron injecting layer on the electron transfer layer, place the cathode layer on the electron injecting layer, it is characterized in that: between described hole transmission layer and the luminescent layer or/and be provided with the embeding layer that is used to improve luminous efficiency between luminescent layer and the electron transfer layer.

Embeding layer thickness of the present invention is between 0.01nm～1nm.

The material that embeding layer of the present invention adopts is red glimmering seven (rubrene) or derivatives thereof.

The luminescent material of luminescent layer of the present invention is fluorescent material or phosphor material.

This invention is adding extremely thin red glimmering seven embeding layers between luminescent layer (EML) and the electron transfer layer (ETL) or between hole transmission layer (HTL) and the luminescent layer (EML).This structure embeds one deck on the basis of original structure, therefore can not conflict mutually with other structure or way.Under other layer structure and the on all four situation of thickness, more whether insert the red glimmering seven device effects that embed of thin layer.Device efficiency after the insertion is not before insert, and spectrum does not change, and efficient is significantly improved.

Comparative structure A (traditional devices structure) and B (band thin red glimmering seven is embedded in the traditional structure), A, the efficient of B is respectively 5.84CD/A and 7.33CD/.The B structure has improved 1.49CD/A than the efficient of A structure, and the color of device does not change (A and B chromaticity coordinates all are 0.65,0.34) (can see from Fig. 2).

After such change, from current-voltage (Fig. 3) and brightness-voltage (Fig. 4) curve, the voltage of structure B device has some rising, and it is big that steepness also becomes a little.But its spectrum does not change, and just brightness obviously strengthens.

The reason that efficient improves has two:

1) glimmering seven embeding layers of Bao Hong have formed the hole and have caught center (hole trap center), at compound tense, the a part of exciton that should flee from luminescent layer is limited in the edge of luminescent layer, has stopped that effectively a part of exciton makes it it is stimulated once more and luminous at the edge at edge-lit;

2) glimmering seven embeding layers of Bao Hong itself are luminous, by

Power transfer is transferred to red illuminating material to energy, makes it luminous.And, the balance of entire device has been played advantageous effect because the effect at center is caught in the hole, the life-span of device also is improved simultaneously.

Description of drawings

Fig. 1 is the ruddiness OLED device overall structure schematic diagram that is provided with red glimmering seven embedding thin layers.

Fig. 2 is the EL spectrum that relatively is provided with red glimmering seven embedding thin layers and does not establish two kinds of device architectures of red glimmering seven embedding thin layers.

Fig. 3 is the voltage-to-current density curve that relatively is provided with red glimmering seven embedding thin layers and does not establish two kinds of device architectures of red glimmering seven embedding thin layers.

Fig. 4 is the electric current-brightness curve that relatively is provided with red glimmering seven embedding thin layers and does not establish two kinds of device architectures of red glimmering seven embedding thin layers.

Embodiment

The making principle of micromolecule Organic Light Emitting Diode is on the substrate of the good ITO of evaporation in advance, in the high vacuum chamber, with mode deposit multilayer functional layer and luminescent layer film on glass substrate of evaporation.Here ITO is as transparent anode.The making step of this luminescent device is as follows:

(a) ito substrate 10 that has cleaned up.

(b) anode ITO 11 substrate O ₂Plasma handles.

(c) being coated with machine rete order is successively: hole injection layer 12, and hole transmission layer 13, red glimmering seven embed thin layer 14, rubescent photosphere 15, red glimmering seven embed thin layer 16, electron transfer layer 17, electron injecting layer 18.Above-mentioned embedding

thin layer

14 and 16 also can only select wherein one deck.

(d) manufacture method of hole injection layer is to mix in the mode of main body and doping with two kinds of materials to steam, and forms P type structure, to reduce device voltage.The concentration of mixing is controlled at 0.5%～10%.The evaporation rate of each evaporation source and temperature all are independent control.Rubescent photosphere 15 luminescent materials are fluorescent material or phosphor material.

(e) during the evaporation embeding layer with low rate control or temperature control, evaporation speed is as much as possible little, the uniformity of film is better like this.General rate controlled is 0.001～0.5 , because red glimmering seven energy transfer efficiencies that embed are 100%, so that these red glimmering seven embeding layers do not need is too thick, thickness is arranged between 0.01nm～1nm.The time of evaporation is not long, can not have influence on productive temp.The material that embeding layer adopts is red glimmering seven or derivatives thereofs.Above-mentioned other each layers are handled routinely.

(f) evaporation negative electrode aluminium 19.

(g) post drier on bonnet, put the glue encapsulation then, whole flow process is all at pure N ₂Carry out in the environment.

The embodiment of the invention one that makes by above-mentioned steps: ITO/2TNATA:F4TCNQ (3%, 100nm)/and NPB (20nm)/rubrene (0.01～1nm)/Alq3+rubrene:red dopant (2%, 50nm)/BPhen (20nm)/LiF (1nm)/Al (150nm)

The embodiment of the invention two that makes by above-mentioned steps: ITO/2TNATA:F4TCNQ (3%, 100nm)/and NPB (20nm)/Alq3+rubrene:red dopant (2%, 50nm)/rubrene (0.01～1nm)/BPhen (20nm)/LiF (1nm)/Al (150nm)

The embodiment of the invention three that makes by above-mentioned steps: ITO/2TNATA:F4TCNQ (3%, 100nm)/and NPB (20nm)/rubrene (0.01～1nm)/Alq3+rubrene:reddopant (2%, 50nm)/rubrene (0.01～1nm)/BPhen (20nm)/LiF (1nm)/Al (150nm).

The efficient of traditional structure and voltage are respectively 5.84CD/A and 5.92V@50mA/cm2, and the above embodiment of the present invention one and two efficient and voltage can reach 7.33CD/A and 6.28V@50mA/cm respectively ²The efficient of embodiment three and voltage can reach 7.28CD/A and 6.97V respectively.

Claims

1, a kind of OLED device that glows, comprise substrate, anode, place the hole injection layer on the anode, place the hole transmission layer on the hole injection layer, place the rubescent photosphere on the hole transmission layer, place the electron transfer layer on the rubescent photosphere, place the electron injecting layer on the electron transfer layer, place the cathode layer on the electron injecting layer, it is characterized in that: between described hole transmission layer and luminescent layer, be provided with the embeding layer that is used to improve luminous efficiency, perhaps be provided with the embeding layer that is used to improve luminous efficiency between luminescent layer and the electron transfer layer, perhaps simultaneously at luminescent layer and electron transfer layer, be provided with the embeding layer that is used to improve luminous efficiency between the hole transmission layer.

2, according to the described OLED device that glows of claim 1, it is characterized in that: described embeding layer thickness is between 0.01nm～1nm.

3, according to the described OLED device that glows of claim 1, it is characterized in that: the material that described embeding layer adopts is red glimmering seven.

4, according to the described OLED device that glows of claim 1, it is characterized in that: the luminescent material of described luminescent layer is fluorescent material or phosphor material.