A kind of organic electroluminescence device of Color tunableTechnical field
The present invention relates to field of organic electroluminescence, and in particular to a kind of organic electroluminescence device of Color tunable.
Background technology
By the development of nearly 30 years, (English full name was Organic Light Emitting to organic electroluminescence deviceDevice, referred to as OLED) as illumination of future generation and Display Technique, with colour gamut is wide, response is fast, wide viewing angle, pollution-free, heightThe advantages of contrast, planarization, a certain degree of application is obtained in illumination and display.Typical organic electroluminescencePart generally comprises transparency carrier 1, first transparency electrode 3, second electrode 5 and is arranged on two interelectrode organic function layers4。
CN101371619 B provide a kind of stack organic luminescent device, and it includes：First conductive layer, at least oneThe luminescence unit of intermediate conductive layer and the second conductive layer and setting between the conductive layers.Wherein, in the conductive layer, extremelyRare two non-conterminous conductive layers are the conductive layers for belonging to group 1, and it, which is electrically connected with each other, reaches same potential；Can not be with categoryIt is electrically connected with and is reached in the conductive layer of same potential in the 1st group of conductive layer, at least one non-conterminous conductive layer is to belong to group 2Conductive layer, it, which is electrically connected with each other, reaches same potential；And belong to the conductive layer of group 1 and pass through with the conductive layer for belonging to group 2The pressure regulator for alternately applying positive voltage and negative voltage is connected with each other.Stack organic luminescent device is adjusted using DC power systemIts colour temperature makes it show different colors.This scheme needs to draw central, clear electrode, and preparation method is difficult；In addition what is applied is anti-To voltage it is higher when, it is possible that leakage current is larger or even situation of breakdown device；When ac power frequency is higher, can alsoThere is the leakage current caused by device capacitor.
US20110095702 discloses a kind of stack organic luminescent device, and it includes：First conductive layer, at least oneThe luminescence unit of intermediate conductive layer and the second conductive layer and setting between the conductive layers.Luminescence unit includes two groups of polarity phasesAnti- luminescence unit, is respectively adopted external drive circuit diode and realizes electrical connection, the device shows dress using DC poweredPut, it is necessary to additionally make external circuitses.
The content of the invention
Therefore, to be solved by this invention is that existing polychrome stacks the problem of OLED must use DC powered, enterAnd the electrically driven (operated) multicolor displaying organic electro luminescent device of exchange can be used by improving one kind, pass through Design assistant PN in the devicesKnot, in the control of single AC power, under conditions of target lead, is distributed by adjusting the alternating current reversal timeRatio, the toning effect that realization can be complete.
In order to solve the above technical problems, the technical solution adopted by the present invention is as follows：
A kind of Organnic electroluminescent device of Color tunable, is included in the first electrode layer, extremely that the stacking on substrate is setA few middle transparent conductive layer and the second electrode lay, first set respectively between the electrode layer and middle transparent conductive layerLuminescence unit and the second luminescence unit set between the middle transparent conductive layer (3) and the second electrode lay, instituteState the current direction that the current direction and second luminescence unit that the first luminescence unit can pass through can pass through opposite；
The middle transparent conductive layer is also provided with unidirectional electricity between the first electrode layer and the second electrode lay respectivelyFlow control valve, the electricity that the current direction that the unidirectional current control valve can pass through can pass through with the luminescence unit set with layerStream flow direction is opposite.
Unidirectional current control valve and first luminescence unit between the first electrode layer and middle transparent conductive layerIt is set up in parallel, the unidirectional current control valve between the middle transparent conductive layer and the second electrode lay and second luminescence unitIt is set up in parallel, is physically contacted between the unidirectional current control valve set with layer and the luminescence unit or passes through insulating barrier thingReason contact.
The unidirectional current control valve is PN junction.
The PN junction includes the first PN junction and the second PN junction, and first PN junction is set side by side with first luminescence unitPut；Second PN junction is set up in parallel with second luminescence unit.
First PN junction and the second PN junction include the first organic function layer and the second organic function layer；First PNThe stacking order for tying each layer is opposite with the stacking order of each layer of the second PN junction.
Each luminescence unit includes the first organic function layer, luminescent layer, the second organic functions for stacking gradually settingLayer；The stacking order of each layer of first luminescence unit is opposite with the stacking order of each layer of second luminescence unit；InstituteState the first PN junction opposite with the order of the second organic function layer with the first organic function layer of the first luminescence unit；2nd PNKnot is opposite with the order of the second organic function layer with the first organic function layer of the second luminescence unit.
First organic function layer includes hole injection layer and/or hole transmission layer, the second organic function layer bagInclude electron transfer layer and/or electron injecting layer.
Described luminescent layer is one kind in red light luminescent layer, Yellow light emitting layer, green light emitting layer, blue light-emitting.
First luminescence unit and the luminescence unit that second luminescence unit is different colours, respectively red light-emittingUnit, Yellow light emitting unit, green luminescence unit, blue light emitting unit piece or white-light emitting unit.
The Organnic electroluminescent device shows multiple color using alternating voltage driving.
S1, first electrode layer is prepared on substrate；
S2, the first luminescence unit of preparation and the first PN junction：
Prepared in the first electrode layer of the side in the first luminescence unit hole injection layer, hole transmission layer, luminescent layer,Electron transfer layer, electron injecting layer, form the first luminescence unit set with the first luminescence unit with layer；
Evaporation electron injecting layer, electron transfer layer, hole transmission layer, hole injection layer are prepared in first electrode layer, is formedFirst PN junction；
S3, on the first luminescence unit and the first PN junction evaporation form middle transparent conductive layer；
S4, the second luminescence unit and the second PN junction are prepared in middle transparent conductive layer：
Electron injecting layer, electron transfer layer, luminescent layer, hole transmission layer, hole note are prepared in middle transparent conductive layerEnter layer, form the second luminescence unit；
Hole injection layer, hole transmission layer, electronics is prepared in the middle transparent conductive layer of the second luminescence unit side to passDefeated layer, electron injecting layer, form the second PN junction set with the second luminescence unit with layer；
S5, on the second luminescence unit and the second PN junction prepare the second electrode lay.
Preferably, after the first luminescence unit of the step S2 completes, one is prepared in the side of the first luminescence unitInsulating film layer, the first PN junction set with the first luminescence unit with layer, described dielectric film are prepared in the opposite side of insulating film layerLayer is located between the first described luminescence unit and first PN junction；
After the second luminescence unit of the step S2 completes, a dielectric film is prepared in the side of the second luminescence unitLayer, the second PN junction set with the second luminescence unit with layer is prepared in the opposite side of insulating film layer, and described insulating film layer is located atBetween the second described luminescence unit and second PN junction.
The above-mentioned technical proposal of the present invention has advantages below compared with prior art：
The present inventor passes through substantial amounts of research, creatively seeks to having using exchanging electrically driven (operated) multicolor displayingOrganic electro luminescent device, the luminescence unit of the Organnic electroluminescent device includes at least one first luminescence unit and at least one secondLuminescence unit, the current direction that can pass through between first luminescence unit and second luminescence unit is opposite；It is describedUnidirectional current control valve is additionally provided between electrode layer, the current direction that the unidirectional current control valve can pass through is set with same layerThe current direction that the luminescence unit put can pass through is opposite.I.e. by Design assistant PN junction in the devices, in single AC powerControl, under conditions of target lead, by adjusting alternating current reversal time-sharing ratio example, what realization can be completelyToning effect.Leakage current can be reduced, the function that single traditional structure device is difficult to is realized.
Brief description of the drawings
In order that present disclosure is more likely to be clearly understood, specific embodiment and combination below according to the present inventionAccompanying drawing, the present invention is further detailed explanation, wherein：
Fig. 1 is the luminescence unit structural representation of existing Color tunable；
Fig. 2 is multicolor displaying organic electro luminescent apparatus structure schematic diagram of the present invention；
Fig. 3 is the current direction schematic diagram of multicolor displaying organic electro luminescent device shown in Fig. 2；
Reference is expressed as in figure：0- substrates, 1- first electrode layers, the PN junctions of 2- first, 3- middle transparent conductive layers, 4-Second PN junction, 5- the second electrode lays, the luminescence units of 6- first, the luminescence units of 7- second.
Embodiment
In order that the object, technical solutions and advantages of the present invention are clearer, below in conjunction with reality of the accompanying drawing to the present inventionThe mode of applying is described in further detail.
The present invention can be embodied in many different forms, and should not be construed as limited to embodiment set forth herein.Opposite there is provided these embodiments so that the disclosure will be thorough and complete, and the design of the present invention will be fully conveyed toThose skilled in the art, the present invention will only be defined by the appended claims.In the accompanying drawings, for clarity, Ceng He areas can be exaggeratedThe size and relative size in domain.It should be appreciated that when element such as layer, region or substrate are referred to as " formation " or " set" another element " on " when, the element can be arranged directly on another element, or can also have intermediary element.On the contrary, when element is referred to as on " being formed directly into " or " being set directly at " another element, in the absence of intermediary element.
As shown in Fig. 2 a kind of organic electroluminescence device of Color tunable of the present invention, is included in the stacking on substrate 0The first electrode layer 1 of setting, at least a middle transparent conductive layer 3 and the second electrode lay 5, it is saturating in the first electrode layer and centreThe first luminescence unit for being set between bright conductive layer 3 and between the middle transparent conductive layer 3 and the second electrode layThe second luminescence unit set, the current direction and second luminescence unit 7 that first luminescence unit 6 can pass through canThe current direction passed through is opposite；The middle transparent conductive layer 3 also respectively with the first electrode layer and with the second electrode lay itBetween be provided with unidirectional current control valve, the current direction that the unidirectional current control valve can pass through with layer set organic work(The current direction that can pass through of ergosphere is opposite.Thing between the unidirectional current control valve set with layer and the luminescence unitReason contact.The unidirectional current control valve is PN junction, its be disposed in parallel in the luminescence unit first electrode layer and inBetween between transparency conducting layer 3 and between middle transparent conductive layer 3 and the second electrode lay.Described PN junction includes the first PNThe PN junction 4 of knot 2 and second, first PN junction 2 is set up in parallel with first luminescence unit 6；Second PN junction 4 and described theTwo luminescence units 7 are set up in parallel.As shown in Fig. 2 the first organic function layer of the first PN junction and the sub-pixel in the first luminescent layerStacking order with the second organic function layer is on the contrary, the first organic function layer of the sub-pixel in the second PN junction and the second luminescent layerIt is opposite with the stacking order of the second organic function layer.As interchangeable mode, set between the PN junction and the luminescence unitInsulating barrier is equipped with, the PN junction is physically contacted with the luminescence unit with the insulating barrier.
Each luminescence unit includes the first organic function layer, luminescent layer, the second organic functions for stacking gradually settingLayer, first organic function layer includes hole injection layer and/or hole transmission layer, and second organic function layer includes electronicsTransport layer and/or electron injecting layer；I.e. each luminescence unit includes stacking gradually hole injection layer, the hole transport of settingLayer, luminescent layer, electron transfer layer and electron injecting layer；The PN junction 4 of first PN junction 2 and second includes the first organic function layerWith the second organic function layer；The stacking order of the stacking order of each layer of first PN junction 2 and each layer of second PN junction 4On the contrary, first organic function layer includes hole injection layer and/or hole transmission layer, second organic function layer includes electricitySub- transport layer and/or electron injecting layer.I.e. described PN junction includes hole injection layer, hole transmission layer, electron transfer layer and electronicsImplanted layer.Hole injection layer, hole transmission layer, luminescent layer, electron transfer layer and the electronics of the first luminescence unit 6 shown in Fig. 2Implanted layer stacking order is upward along substrate, i.e. hole injection layer formation is in first electrode layer 1, and hole transmission layer formation is in instituteState on hole injection layer, luminescent layer formation is electron transfer layer and electron injecting layer on hole transmission layer, on luminescent layer.It is describedThe sense of current that first luminescence unit 6 allows is by first electrode layer to middle transparent conductive layer.6 liang of first luminescence unitEnd is electrically connected with the first electrode layer 1 and middle transparent conductive layer 3 respectively.The hole injection layer of first PN junction 2, holeTransport layer, electron transfer layer and electron injecting layer stacking order are downward along middle transparent conductive layer, i.e., electron injecting layer is formedIn first electrode layer 1, electron transfer layer formation is on the electron injecting layer, and hole transmission layer formation is in upper electric transmissionLayer, hole injection layer formation is on hole transmission layer.The N poles of first PN junction are electrically connected with the first electrode layer 1, P polesElectrically connected with the middle transparent conductive layer 3.
Hole injection layer, hole transmission layer, luminescent layer, electron transfer layer and the electron injecting layer of second luminescence unitStacking order is, the i.e. electron injecting layer formed between transparency conducting layer 3 of second luminescence unit downward along the second electrode lay 5On, electron transfer layer formation is above the electron injecting layer, and luminescent layer formation is square on the electron transport layer, hole transportLayer is formed above luminescent layer, and hole injection layer is formed below above hole transmission layer, the electric current that the second luminescence unit 7 allowsDirection is by the second electrode lay 5 to middle transparent conductive layer 3.The hole injection layer of second luminescence unit 7 and the described second electricityPole layer 5 is electrically connected, and electron injecting layer and middle transparent conductive layer 3 are electrically connected.The hole injection layer of second PN junction 4, holeTransport layer, electron transfer layer and electron injecting layer stacking order are upward along middle transparent conductive layer, i.e., hole injection layer is formedOn transparent electrode layer 3, hole transmission layer formation is on the hole injection layer, and electron transfer layer formation is in the injection of upper holeLayer, electron injecting layer formation is on the electron transport layer.The P poles of second PN junction are electrically connected with the middle transparent conductive layer 3,N poles are electrically connected with the second electrode lay 5.
Described luminescent layer is one kind in red light luminescent layer, green light emitting layer, blue light-emitting.Described first is luminous singleIt is member 6 and the luminescence unit that second luminescence unit 7 is different colours, respectively red light-emitting unit, Yellow light emitting unit, greenLight luminescence unit, blue light emitting unit piece or white-light emitting unit.
As shown in figure 3, when applying alternating voltage to Organnic electroluminescent device shown in Fig. 2, if the sense of current is theWhen one electrode layer 1 flows to the second electrode lay 5.Current direction is dashed lines shown in the direction of arrow：
1 → the first luminescence unit of first electrode layer → middle transparent conductive layer 3 → the second, 4 → the second electrode lay of PN junction 5, thisWhen the color that shows of Organnic electroluminescent device be the first luminescence unit 6 color；
Conversely, after alternating voltage change direction, its current direction is to as shown in solid arrow direction in figure：
5 → the second luminescence units of the second electrode lay → middle transparent conductive layer 3 → the first, 2 → first electrode layer of PN junction 1, thisWhen the color that shows of Organnic electroluminescent device be the second luminescence unit 7 color；
The color of Organnic electroluminescent device changes with the change of the positive and negative time scale of alternating current.
The preparation method of the Organnic electroluminescent device of above-mentioned Color tunable comprises the steps：
A kind of preparation method of Organnic electroluminescent device, comprises the steps：
S1, with the method for ultrasonic detergent and the deionized water ultrasound boiled ito glass substrate is cleaned, and placedDried under infrared lamp, first electrode layer 1 is prepared on substrate；
S2, the first luminescence unit 6 of preparation and the first PN junction 2；
Hole injection layer, hole transmission layer, luminescent layer, electronics is deposited in first electrode layer 1 using metal mask plate to passDefeated layer, electron injecting layer, form the first luminescence unit 6；Its structure is as follows：MoOx/NPB/TCTA/CBP:12%YD/Bphen/LiF；
Insulating film layer is prepared in the first electrode layer 1 of the side (being left side in Fig. 2) of the first luminescence unit 6；
In first electrode layer 1, electron injection is deposited in the opposite side using another metal mask plate in insulating film layer successivelyLayer, electron transfer layer, hole transmission layer, hole injection layer, form the first PN junction 2；Its structure is as follows：Ag/LiF/n types organic halfConductor (Liq, BCP, Bphen etc.)/p-type organic semiconductor (NPB, TCTA etc.)/MoOx；
S3, on the first luminescence unit 6 and the first PN junction 2 evaporation form middle transparent conductive layer 3；
S4, the second luminescence unit 7 and the second PN junction 4 are prepared in middle transparent conductive layer 3
Electron injecting layer, electron transfer layer, luminescent layer, sky are prepared in middle transparent conductive layer 3 using metal mask plateCave transport layer, hole injection layer, form the second luminescence unit 7；Its structure is as follows：LiF/Bphen/BH:5%BD//TCTA/NPB/MoOx；
Insulating film layer is prepared in the middle transparent conductive layer 3 of the side (being left side in Fig. 2) of the second luminescence unit 7；
In middle transparent conductive layer 3, use another metal mask plate in the opposite side of insulating film layer (for left side in Fig. 2)Evaporation hole injection layer, hole transmission layer, electron transfer layer, electron injecting layer, form the second PN junction 4 successively；Its structure is as follows：MoOx/p types organic semiconductor (NPB, TCTA etc.)/n-type organic semiconductor (Liq, BCP, Bphen etc.)/LiF；
S5, on the second luminescence unit 7 and the second PN junction 4 evaporation form the second electrode lay 5.
As interchangeable mode, when preparing the first PN junction 2 and the second PN junction 4, can be set respectively with same layer theOne luminescence unit 6 and the part of the second luminescence unit 7, which are overlapped, makes direct physics between the PN junction and the luminescence unit set with layerContact, it is to avoid central, clear electrode 3 is directly logical with first electrode 1 and/or the Direct Conductivity of second electrode 5.PN junction and the hair with layerLight unit has insulating barrier between can overlapping setting or both, plays a part of insulation target and the first second electrode.
Obviously, above-described embodiment is only intended to clearly illustrate example, and the not restriction to embodiment.It is rightFor those of ordinary skill in the art, can also make on the basis of the above description it is other it is various forms of change orChange.There is no necessity and possibility to exhaust all the enbodiments.And the obvious change thus extended out orAmong changing still in protection scope of the present invention.