WO2016070503A1 - 单色oled及其制作方法和oled显示面板 - Google Patents

单色oled及其制作方法和oled显示面板 Download PDF

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WO2016070503A1
WO2016070503A1 PCT/CN2015/072211 CN2015072211W WO2016070503A1 WO 2016070503 A1 WO2016070503 A1 WO 2016070503A1 CN 2015072211 W CN2015072211 W CN 2015072211W WO 2016070503 A1 WO2016070503 A1 WO 2016070503A1
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layer
oled
luminescent
carrier control
layer formed
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PCT/CN2015/072211
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French (fr)
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白娟娟
吴海东
金泰逵
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京东方科技集团股份有限公司
鄂尔多斯市源盛光电有限责任公司
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Priority to US14/784,205 priority Critical patent/US9634274B2/en
Publication of WO2016070503A1 publication Critical patent/WO2016070503A1/zh

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Definitions

  • the present disclosure relates to an OLED (Organic Light Emitting Diode) technology, and in particular to a monochrome OLED, a method of fabricating the same, and an OLED display panel.
  • OLED Organic Light Emitting Diode
  • OLEDs have shown broad application prospects in the field of flat panel display and illumination due to their advantages of high efficiency, low voltage, flexibility, and surface illumination.
  • efficient and stable white light is especially important.
  • the white light can be obtained by combining the three primary colors of red, blue and green or the compensation light of blue and orange. Therefore, in the process of industrialization of white OLEDs, efficient and stable monochromatic light plays an irreplaceable role.
  • Important factors affecting OLED performance include: differences in carrier concentration in the luminescent layer and effective exciton recombination regions in the luminescent layer.
  • the carriers include electrons and holes, and the greater the difference in concentration of electrons and holes in the light-emitting layer, the worse the performance of the OLED.
  • electrons and holes need to be combined in the light-emitting layer to form excitons to achieve light emission. The smaller the effective exciton recombination region in the light-emitting layer, the less electrons and holes that can form excitons, and the OLED performance. The worse.
  • the balance of carrier concentration in the light-emitting layer is improved, but these methods are difficult to achieve. Satisfactory effect.
  • a host-guest dopant material is used as the light-emitting layer, it is difficult to achieve a very accurate doping ratio, so that a balance of carrier concentration cannot be achieved.
  • the carrier transport layer and the carrier block layer are relatively simple to fabricate, they have a certain loss in terms of photoelectric characteristics such as brightness and efficiency of the device.
  • the OLEDs produced by the prior art also have the drawback that the performance cannot meet the demand.
  • An object of the embodiments of the present disclosure is to provide a monochrome OLED, a manufacturing method thereof, and an OLED display panel to improve the performance of the OLED.
  • an embodiment of the first aspect of the present disclosure provides a monochrome OLED.
  • the monochrome OLED includes a light emitting layer, wherein the light emitting layer includes:
  • At least one illuminating sublayer At least one illuminating sublayer
  • At least one carrier control layer adjacent to the luminescent sublayer wherein the carrier control layer is used to control a concentration ratio of carriers of different polarities within the luminescent layer.
  • the concentration ratio is about 1.5:1 to 1:1.5.
  • the number of the carrier control layers is 1 or 2 layers.
  • the second material forming the carrier control layer and the first material forming the luminescent sub-layer have opposite polarities.
  • the second material when the first material is a partial hole transport type material, the second material is a partial electron transport type material; when the first material is a partial electron transport type material, the second material is biased Hole transport type material.
  • the concentration ratio is set according to a thickness of the illuminating sublayer, a thickness of the carrier control layer, and a spacing between the illuminating sublayer and the carrier control layer.
  • a highest occupied molecular orbital of the first material and the second material satisfies a first predetermined relationship
  • a lowest unoccupied empty orbit of the first material and the second material satisfies a second predetermined relationship to A carrier-controlled electric field
  • the first material is a partial electron transport type
  • the absorption spectrum of the second material and the luminescence spectrum of the first material do not overlap.
  • the first material forming the luminescent sub-layer is a blue fluorescent dye.
  • the blue fluorescent dye is an anthracene derivative, an anthracene derivative, an anthracene derivative or an anthracene derivative.
  • the blue fluorescent dye is DSA-ph, BCzVBi, 1,4,7,10-tetra-tert-butylperylene, DPVBI, N-BDAVBi or BDAVBi.
  • the monochrome OLED specifically includes:
  • the monochrome OLED specifically includes:
  • At least one luminescent sub-layer formed by DNCA At least one luminescent sub-layer formed by DNCA
  • An electron injecting layer formed by LiF LiF
  • the monochrome OLED specifically includes:
  • An electron injecting layer formed by LiF LiF
  • an embodiment of the second aspect of the present disclosure also provides a method of fabricating a monochrome OLED.
  • the method includes the steps of forming a light-emitting layer, and the step of forming the light-emitting layer specifically includes:
  • the concentration ratio is about 1.5:1 to 1:1.5.
  • forming a second material of the carrier control layer and forming a first of the luminescent sub-layer The materials have opposite polarities.
  • a highest occupied molecular orbital of the first material and the second material satisfies a first predetermined relationship
  • a lowest unoccupied empty orbit of the first material and the second material satisfies a second predetermined relationship to A carrier-controlled electric field
  • the first material is a partial electron transport type
  • the absorption spectrum of the second material and the luminescence spectrum of the first material do not overlap.
  • an embodiment of the third reverse side of the present disclosure further provides an OLED display panel including the above-described monochrome OLED.
  • Embodiments of the present disclosure are directed to the problem of poor performance existing in a monochrome OLED fabricated in the prior art, by increasing the carrier control layer in the light-emitting layer to control the concentration ratio of carriers of different polarities in the light-emitting layer, thereby improving The performance of OLED.
  • FIG. 1a-1f are schematic views showing the structure of a light-emitting layer in a monochrome OLED according to an embodiment of the present disclosure
  • FIG. 2 is a schematic view showing a barrier formed between a light-emitting sublayer and a carrier control layer
  • FIG. 3 is a schematic flow chart showing a method of fabricating a monochrome OLED according to an embodiment of the present disclosure
  • 4a-6 are schematic diagrams showing experimental results of an embodiment of the present disclosure.
  • the embodiments of the present disclosure are directed to the problem of poor performance existing in the monochromatic OLED fabricated in the prior art, by increasing the carrier control layer in the luminescent layer to control the concentration ratio of carriers of different polarities in the luminescent layer to improve The performance of OLEDs.
  • a monochrome OLED according to an embodiment of the present disclosure includes a light emitting layer, as shown in FIGS. 1a-1f, the light emitting layer includes:
  • At least one illuminating sub-layer 101 At least one illuminating sub-layer 101;
  • the number of the illuminating sublayers and the number of the carrier control layers may be equal, or the number of the illuminating sublayers may be one more, or may be the illuminating sublayer. The number is one less. All of these cases enable the function of controlling the concentration ratio of carriers of different polarities in the light-emitting layer, which will be explained later in theory and actual simulation.
  • the generation of holes and electrons requires a certain amount of energy, and the light generated by the OLED comes from the excitons formed by the combination of electron-hole pairs.
  • the hole concentration and the electron concentration are different, some holes or electrons cannot combine to form excitons. Then, some of the excess holes or electrons cannot be combined to form excitons, which causes carrier loss, reduces carrier utilization, and is not conducive to the improvement of OLED performance.
  • the concentration ratio of the electron concentration and the hole concentration in the light-emitting layer is controlled to be between 1.5:1 and 1:1.5, thereby satisfying the actual product. demand.
  • the monochromatic OLED of the embodiment of the present disclosure can control the concentration ratio of carriers of different polarities in the light-emitting layer, thereby being capable of improving the performance of the OLED, which is explained below.
  • An exciton is an unstable electron-hole pair formed by electrons and holes in a substance having luminescent properties, and finally releases energy in the form of light or heat to return to a stable ground state.
  • the form in which the excitons return to the stable ground state is closely related to the exciton concentration. If the region where the exciton is formed is too narrow, it will cause the exciton to be too concentrated in a very narrow composite region, and the excessive exciton concentration will lead to the quenching of the excitons, that is, the excitons are in the form of heat rather than The way the light energy returns to the ground state will reduce the performance of the OLED.
  • the recombination region of the excitons is increased, and the exciton concentration in the recombination region is reduced, thereby reducing the exciton quenching condition (ie, the excitons are in thermal energy mode).
  • the return to the ground state increases the proportion of excitons returning to the ground state in the form of light energy, improving the performance of the OLED.
  • the host-guest dopant material is used as the light-emitting layer in the prior art, it is difficult to achieve a very precise doping ratio, and thus it is impossible to achieve a balance of carrier concentration.
  • the method of the embodiments of the present disclosure can be realized by multi-layer sequential evaporation from the manufacturing process, and the evaporation can realize very precise size control, which is easier to control than the doping ratio of the host-guest doping.
  • the implementation and repeatability are also good, so that accurate carrier concentration balance can be achieved with a relatively simple and low cost process.
  • the carrier control layer can be implemented in various ways, The following several possible implementations are described below, but should not be construed as limiting the scope of the disclosure.
  • Example 1 the second material forming the carrier control layer and the first material forming the illuminating sub-layer have opposite polarities to control carriers of different polarities within the luminescent layer The concentration ratio.
  • a charge carrier refers to a chargeable substance particle that can move freely.
  • electrons and holes become carriers.
  • the organic charge transporting material is a kind of organic semiconductor material which can realize the directed and orderly controlled migration of carriers under the action of an electric field when the carrier (electron or hole) is injected, thereby achieving the charge transfer.
  • the material of the partial hole transport type as the light emitting sublayer is formed includes:
  • DNCA N6, N6, N12, N12-tetra-methylphenyl -6,12-diamine, partial toluene
  • the material of the partial electron transport type as the light-emitting sub-layer is formed includes:
  • ADN (9,10-di(2-naphthyl)anthracene
  • TBPe (1,4,7,10-tetra-tert-butylperylene
  • the transmission polarity is assumed to be the first polarity (which may be N-type or P-type).
  • the concentration ratio of the polar carriers is introduced into the carrier control layer, and since the polarity of the transport of the material is opposite to the polarity of the material used for the illuminating sublayer, that is, the opposite polarity of the two, The thickness difference between the two and the interval setting are controlled to control the concentration ratio of carriers in the light-emitting layer.
  • the thickness of the N-type material may be increased or the thickness of the P-type material may be decreased.
  • the concentration ratio of electrons in the light-emitting layer can be increased by increasing the thickness of the P-type material or decreasing the thickness of the N-type material.
  • the second material when the first material is a hole transporting type material, The second material is a partial electron transport type material; when the first material is a partial electron transport type material, the second material is a partial hole transport type material, and further, a layer formed by controlling the first material and the second material
  • the thickness of the structure and the interval of the layers to control the concentration ratio of the carriers in the light-emitting layer that is, the concentration ratio of the carriers according to the thickness of the light-emitting sub-layer, the thickness of the layer controlled by the carriers, and the luminescent sub-layer and the carrier
  • the interval of the stream control layer is set.
  • a certain barrier is formed in the luminescent layer, and the blocking part of the carrier continues to penetrate into the luminescent layer, so that carriers that cannot continue to enter the luminescent layer accumulate in the luminescent layer.
  • the formation of the above-described carrier-controlled electric field can be achieved by the highest occupied molecular orbital HOMO (Highest Occupied Molecular Orbital) of the first material and the second material and the lowest unoccupied molecular orbital LUMO (Lowest Unoccupied Molecular Orbital).
  • HOMO Highest Occupied Molecular Orbital
  • LUMO Low Unoccupied Molecular Orbital
  • the HOMO energy level difference of the highest occupied molecular orbitals of the two materials will affect the injection of holes, and the lowest unoccupied orbital LUMO energy level difference of the two materials will affect the electron injection.
  • the larger the HOMO energy level difference the ability to block holes.
  • a material having a smaller LUMO energy level than the LUMO energy level of the light-emitting layer material can be selected as the carrier control layer to reduce the LUMO energy level difference and enhance electron injection. To increase the concentration of electrons in the luminescent layer.
  • a material having a smaller HOMO level of the HOMO level and the HOMO level of the light-emitting layer material can be selected as the carrier control layer to reduce the HOMO level difference and enhance the hole. Injection increases the concentration of holes in the luminescent layer.
  • DNCA N6, N6, N12, N12-tetra-methylbenzox-6,12-diamine, partial toluene
  • BPhen 4,7-diphenyl-1,10- Schematic representation of HOMO and LUMO of phenanthroline. It can be seen from Fig.
  • the HOMO level of DNCA is -2.6eV
  • the LUMO level is -5.2eV
  • the HOMO level of Bphen is -2.9eV
  • the LUMO level is -6.4eV
  • the HOMO energy level difference is only 0.3eV, that is, the difference between the HOMO level of DNCA (-2.6eV) and the HOMO level of Bphen (-2.9eV) is relatively small, so a large number of holes can overcome the above-mentioned energy of 0.3eV.
  • the grade is transmitted in the DNCA and reaches the junction of DNCA and Bphen.
  • the LUMO level that needs to be overcome The difference is 1.2 eV, which is the difference between the LUMO level of DNCA (-5.2 eV) and the LUMO level of Bphen (-6.4 eV), which is a very large energy level difference for electrons and is difficult to overcome, thus achieving The block of electrons.
  • the concentration ratio of electrons and holes is between 1.5:1 and 1:1.5
  • the first material is a partial electron transport type
  • a potential barrier for attracting or blocking carriers can be formed in the light-emitting layer, thereby affecting different polarities in the light-emitting layer.
  • the concentration ratio of carriers is to say, in the embodiment of the present disclosure, by selecting different materials in which HOMO and LUMO respectively satisfy a certain relationship, a potential barrier for attracting or blocking carriers can be formed in the light-emitting layer, thereby affecting different polarities in the light-emitting layer.
  • the luminescence is mainly realized by the first material, and since the carrier control layer is added, the carrier control layer added in the embodiment of the present disclosure does not affect the light generated by the luminescent layer.
  • An exemplary implementation is to ensure that the absorption spectrum of the second material forming the carrier control layer and the luminescence spectrum of the first material forming the luminescent sublayer do not overlap.
  • the embodiment of the present disclosure does not reduce the luminous efficiency of the monochromatic OLED.
  • the monochromatic OLED of the specific embodiment of the present disclosure may be a fluorescent OLED of various colors.
  • the monochromatic OLED is a blue OLED
  • the first material forming the illuminating sub-layer is a blue fluorescent dye. .
  • the blue fluorescent dye may be an anthracene derivative, an anthracene derivative, an anthracene derivative or an anthracene derivative.
  • the blue fluorescent dye may also be: DSA-ph (1,4-bis[4-(N,N-diphenyl)amino]styrylbenzene), BCzVBi (4,4'-double (9- Ethyl-3-carbazolevinyl)-1,1'-biphenyl), TBPe (1,4,7,10-tetra-tert-butylperylene), DPVBi([4,4'-(2) , 2-styryl)-1,1'-biphenyl]), BDAVBi (4,4'-bis[4-(diphenylamino)styryl]biphenyl) or N-BDAVBi.
  • the embodiment of the present disclosure further provides a method for fabricating a monochromatic OLED, including the step of forming a luminescent layer. As shown in FIG. 3, the step of forming the luminescent layer specifically includes:
  • Step 301 forming at least one illuminating sublayer
  • Step 302 forming at least one carrier control layer adjacent to the illuminating sublayer, wherein The carrier control layer is used to control the concentration ratio of carriers of different polarities in the light-emitting layer.
  • Controlling the concentration ratio of carriers of different polarities can be achieved in two ways:
  • the HOMO of the first material and the second material satisfy a first predetermined relationship
  • the LOMO of the first material and the second material satisfy a second predetermined relationship to form a carrier control electric field, wherein the The flow control electric field is used to control the concentration ratio of carriers of different polarities in the light-emitting layer.
  • the ITO layer is first etched into a desired pattern according to the mask of the design, and then the substrate is sequentially cleaned and treated with an organic solvent, ozone, or the like. Then, the ITO substrate is placed in a vacuum coating machine, and when the pressure in the chamber drops to 2 ⁇ 10 ⁇ 4 Pa, the hole transport layer, the light-emitting layer including the carrier control layer structure, and the electron transport layer are sequentially performed on the ITO layer. The evaporation of the electron injecting layer and the cathode is performed, and finally the ITO surface is packaged by a glass cover.
  • the absorption spectrum of the second material forming the carrier control layer and the emission spectrum of the first material forming the emission sublayer do not overlap.
  • an embodiment of the present disclosure further provides an OLED display panel including the above-described monochrome OLED.
  • the OLED A produced in the prior art is as follows, including ITO, NPB (N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'- in this order.
  • a hole transport layer formed of diamine) (40 nm)
  • a light-emitting layer formed of DPVBi (4,4'-bis(2,2-distyrenyl)-1,1'-biphenyl) (30 nm)
  • BPhen (4 , 7-diphenyl-1,10-phenanthroline) (30 nm) formed electron transport layer
  • LiF (lithium fluoride) (0.6 nm) formed electron injection layer
  • Al aluminum
  • An OLED B of an embodiment of the present disclosure includes, as follows, a hole transport layer formed of ITO, NPB (40 nm), a luminescent sublayer formed of DPVBi (10 nm), and DSA-Ph (1,4-bis[4]. a carrier control layer formed of -(N,N-diphenyl)-amino]styrylbenzene) (5 nm), an illuminant layer formed of DPVBi (20 nm), an electron transport layer formed of BPhen (30 nm), LiF (0.6 nm) formed electron injection layer, and a cathode formed of Al (120 nm);
  • OLED C of the embodiment of the present disclosure includes, as follows, a hole transport layer formed of ITO, NPB (40 nm), a luminescent sublayer formed by DPVBi (20 nm), and a current carrying current formed by DSA-Ph (5 nm).
  • Sub-control layer luminescent sublayer formed by DPVBi (10 nm), electrons formed by BPhen (30 nm)
  • a transport layer an electron injecting layer formed of LiF (0.6 nm), and a cathode formed of Al (120 nm).
  • Figure 4a is a comparison of test data for voltage-current density and voltage-luminance of the above three OLEDs, which can be found from Figure 4a (where the arrows in Figures 4a and 6 represent the axis of the ordinate axis of the curve)
  • the upper set of curves is a voltage-current density curve
  • the lower set of curves is a voltage-brightness curve: compared to the prior art OLED A, the disclosed embodiment OLEDs B and C achieve higher brightness at the same drive voltage.
  • Figure 4b is a comparison of experimental data of current density-current efficiency of the above three OLEDs. It can be seen from Fig. 4b that OLEDs B and C of the embodiments of the present disclosure are the same in comparison with the prior art OLED A. Higher current efficiencies are achieved at current densities, and current efficiency improvements are significant.
  • the OLEDs B and C of the embodiments of the present disclosure can achieve higher brightness and higher current efficiency under the same driving voltage, but the current density of the three. There are no significant differences.
  • BAlq is used as the carrier control layer
  • the HOMO level of DPVBi is the same as that of BAlq
  • the LUMO level of BAlq is different from the LUMO level of BPhen by 0.1eV, so that the different luminescent layers are empty.
  • the hole is in a decreasing concentration.
  • the barrier of 0.1eV facilitates the entry of electrons from the electron transport layer into the light-emitting layer, and the strong electron transport capability of BAlq itself facilitates the transport of electrons in the light-emitting layer, thereby facilitating the balance of electron-hole pairs and making the device
  • the brightness increases.
  • the number of layers of the carrier control layer is less than or equal to two.
  • the electron concentration and the hole concentration in the light-emitting layer are at an appropriate ratio, thereby greatly reducing electrons or holes that cannot form excitons, and improving carrier. Utilization improves the performance of OLEDs.
  • the recombination region of the excitons is expanded, the exciton concentration is lowered, and the exciton quenching condition is reduced (ie, the excitons return to the ground state by thermal energy).
  • the occurrence of this improves the proportion of excitons returning to the ground state in the form of light energy, which improves the performance of the OLED.

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Abstract

一种单色OLED、制作方法及OLED显示面板。所述OLED包括发光层，其中所述发光层包括：至少一个发光子层（101）；以及至少一个与所述发光子层（101）相邻的载流子控制层（102），其中所述载流子控制层（102）用于控制所述发光层内的不同极性的载流子的浓度比例。

Description

单色OLED及其制作方法和OLED显示面板
相关申请的交叉引用
本公开主张在2014年11月7日在中国提交的中国专利申请号No.201410643039.5的优先权，其全部内容通过引用包含于此。
技术领域
本公开涉及OLED(Organic Light Emitting Diode，有机发光二极管)技术，特别地涉及单色OLED及其制作方法和OLED显示面板。
背景技术
OLED由于其可实现高效低压、柔性化、面发光等优势而在平板显示与照明领域显示了广阔的应用前景。
不管是应用于何种形式，高效稳定的白光显得尤为重要。白光的获得可以是红、蓝、绿三基色或蓝与橙两种补偿光组合而成。因此，在白色OLED产业化的进程中，高效稳定的单色光发挥着不可替代的作用。
对于磷光掺杂发光系统而言，由于各种缺陷使得其应用收到很大的限制，因此现在越来越多的OLED采用单色荧光材料作为发光层。
而影响OLED性能的重要因素包括：发光层中载流子浓度的差异以及发光层中有效的激子复合区域。载流子包括电子和空穴，当发光层中电子和空穴的浓度差距越大，则OLED性能的越差。同样，电子和空穴需要在发光层中复合形成激子才能实现发光，发光层中有效的激子复合区域越小，则能够复合形成激子的电子和空穴就越少，则OLED性能的越差。
现有技术中通过设置载流子传输层、载流子阻挡层、改变用作发光层的主客体掺杂材料等方式来提高发光层中载流子浓度的平衡性，但这些方式都难以达到令人满意的效果。如采用主客体掺杂材料作为发光层时，由于难以实现非常精确的掺杂比例，因此导致无法实现载流子浓度的平衡。又如载流子传输层、载流子阻挡层等虽然制作比较简单，但在器件亮度、效率等光电特性方面又会带来一定的损失。
因此，现有技术生产的OLED还存在性能无法满足需求的缺陷。
发明内容
本公开实施例的目的在于提供一种单色OLED及其制作方法和OLED显示面板，以提高OLED的性能。
为了实现上述目的，本公开第一方面的实施例提供了一种单色OLED。根据本公开的实施例，所述单色OLED包括发光层，其中所述发光层包括：
至少一个发光子层；以及
至少一个与所述发光子层相邻的载流子控制层，其中所述载流子控制层用于控制所述发光层内的不同极性的载流子的浓度比例。
可选地，所述浓度比例约为1.5∶1～1∶1.5。
可选地，所述载流子控制层的数量为1层或2层。
可选地，形成所述载流子控制层的第二材料和形成所述发光子层的第一材料具有相反的极性。
可选地，所述第一材料为偏空穴传输型材料时，所述第二材料为偏电子传输型材料；所述第一材料为偏电子传输型材料时，所述第二材料为偏空穴传输型材料。
可选地，所述浓度比例根据所述发光子层的厚度、所述载流子控制层的厚度以及所述发光子层与所述载流子控制层的间隔方式设置。
可选地，所述第一材料和所述第二材料的最高占据分子轨道满足第一预定关系，所述第一材料和所述第二材料的最低未占据空轨道满足第二预定关系，以形成载流子控制电场。
可选地，当所述第一材料为偏空穴传输型时，所述第一材料与所述第二材料的所述最高占据分子轨道的能级差＞＝0.5eV，所述第一材料与所述第二材料的最低未占据空轨道的能级差应＜＝0.4Ev；当所述第一材料为偏电子传输型时，所述第一材料与所述第二材料的所述最高占据分子轨道的能级差＜＝0.5eV，所述第一材料与所述第二材料的最低未占据空轨道的能级差应＞＝0.1eV。
可选地，所述第二材料的吸收光谱和所述第一材料的发光光谱不重叠。
可选地，形成所述发光子层的第一材料为蓝色荧光染料。
可选地，所述蓝色荧光染料为蒽衍生物、苝衍生物、芘衍生物或芴衍生物。
可选地，所述蓝色荧光染料为DSA-ph、BCzVBi、1，4，7，10-四叔丁基二萘嵌苯、DPVBI、N-BDAVBi或BDAVBi。
可选地，所述单色OLED具体包括：
ITO层；
NPB形成的空穴传输层；
DPVBi形成的至少一个发光子层；
DSA-Ph形成的至少一个载流子控制层；
BPhen(30nm)形成的电子传输层；
LiF(0.6nm)形成的电子注入层；以及
Al形成的阴极；
或者所述单色OLED具体包括：
ITO层；
NPB形成的空穴传输层；
DNCA形成的至少一个发光子层；
Alq3形成的载流子控制层；
BPhen形成的电子传输层；
LiF形成的电子注入层；以及
Al(120nm)形成的阴极；
或者所述单色OLED具体包括：
ITO层；
NPB形成的空穴传输层；
DPVBi形成的至少一个发光子层；
BAlq形成的至少一个载流子控制层；
BPhen形成的电子传输层；
LiF形成的电子注入层；以及
Al形成的阴极。
为了实现上述目的，本公开第二方面的实施例还提供了一种制作单色OLED的方法。根据本公开的实施例，所述方法包括形成发光层的步骤，所述形成发光层的步骤中具体包括：
形成至少一个发光子层；以及
形成至少一个与所述发光子层相邻的载流子控制层，其中所述载流子控制层用于控制所述发光层内的不同极性的载流子的浓度比例。
可选地，所述浓度比例约为1.5∶1～1∶1.5。
可选地，形成所述载流子控制层的第二材料和形成所述发光子层的第一 材料具有相反的极性。
可选地，所述第一材料和所述第二材料的最高占据分子轨道满足第一预定关系，所述第一材料和所述第二材料的最低未占据空轨道满足第二预定关系，以形成载流子控制电场。
可选地，当所述第一材料为偏空穴传输型时，所述第一材料与所述第二材料的所述最高占据分子轨道的能级差＞＝0.5eV，所述第一材料与所述第二材料的最低未占据空轨道的能级差应＜＝0.4Ev；当所述第一材料为偏电子传输型时，所述第一材料与所述第二材料的所述最高占据分子轨道的能级差＜＝0.5eV，所述第一材料与所述第二材料的最低未占据空轨道的能级差应＞＝0.1eV。
可选地，所述第二材料的吸收光谱和所述第一材料的发光光谱不重叠。
为了实现上述目的，本公开第三反面的实施例还提供了一种包括上述单色OLED的OLED显示面板。
本公开的实施例针对现有技术制作的单色OLED中存在的性能较差的问题，通过在发光层增加载流子控制层来控制发光层内不同极性的载流子的浓度比例，提高了OLED的性能。
附图说明
图1a-图1f表示本公开实施例的单色OLED中发光层的结构示意图；
图2表示发光子层和载流子控制层之间形成的势垒的示意图；
图3表示本公开实施例的单色OLED的制作方法的流程示意图；
图4a-图6为本公开实施例的实验结果示意图。
具体实施方式
本公开实施例针对现有技术制作的单色OLED中存在的性能较差的问题，通过在发光层增加载流子控制层来控制发光层内不同极性的载流子的浓度比例，以提高OLED的性能。
根据本公开实施例的单色OLED，包括发光层，如图1a-图1f所示，所述发光层包括：
至少一个发光子层101；以及
至少一个与所述发光子层相邻的载流子控制层102，其中所述载流子控制层102用于控制所述发光层内的不同极性的载流子的浓度比例。
从图1a-图1f可以发现，在本公开具体实施例中，发光子层的数量和载流子控制层的数量可以相等，也可以是发光子层的数量多一个，还可以是发光子层的数量少一个。而所有的这些情况都能够实现控制所述发光层内的不同极性的载流子的浓度比例的功能，这将在后面进行理论说明和实际的仿真说明。
空穴和电子的产生都需要一定的能量，而OLED产生的光来自于电子空穴对复合形成的激子，当空穴浓度和电子浓度不同时，则部分空穴或电子无法结合形成激子，则这部分多余的空穴或电子无法复合形成激子的载流子，造成了载流子的流失，降低了载流子的利用率，不利于OLED性能的提高。
因此，从理想情况而言，当发光层内电子浓度和空穴浓度相同时，则OLED的性能最高，但考虑到保证发光层内电子浓度和空穴浓度相同需要非常高的工艺精度，因此，在本公开的具体实施例中，只需要通过增加载流子控制层，控制发光层内的电子浓度和空穴浓度的浓度比例在1.5∶1～1∶1.5之间，即可满足实际产品的需求。
本公开实施例的单色OLED能够控制所述发光层内的不同极性的载流子的浓度比例，从而能够提高OLED的性能，对此解释如下。
激子是电子与空穴在具有发光特性的物质中形成的不稳定的电子-空穴对，最后以光或热的形式释放能量而回到稳定的基态。而激子回到稳定基态的形式与激子浓度密切相关。如果复合形成激子的区域过窄，将会导致激子在很窄的复合区域中浓度过大，而激子浓度过大将会导致激子的淬灭，即激子以热能的方式而不是以光能的方式回到基态，会降低了OLED的性能。在本公开具体实施例中，由于载流子控制层的增加，增加了激子的复合区域，降低了复合区域内的激子浓度，因此减少了激子淬灭情况(即激子以热能方式回到基态)的发生，提高了激子以光能方式回到基态的比例，提高了OLED的性能。
现有技术中采用主客体掺杂材料作为发光层时，难以实现非常精确的掺杂比例，因此导致无法实现载流子浓度的平衡。而本公开实施例的方法，从制作工艺来看，采用多层顺序蒸镀即可实现，而蒸镀可以实现非常精确的尺寸控制，其相较于主客体掺杂的掺杂比例控制更加容易实现，重复性也较好，因此能够以相对比较简单和成本较低的工艺流程实现精确的载流子浓度平衡。
在本公开的具体实施例中，该载流子控制层可以通过多种方式实现，下 面就几种可能的实现方式说明如下，但不应当作为对本公开保护范围的限定。
示例一
在示例一中，实现形成所述载流子控制层的第二材料和形成所述发光子层的第一材料具有相反的极性，以控制所述发光层内的不同极性的载流子的浓度比例。
在物理学中，载流子(Charge Carrier)指可以自由移动的带有电荷的物质微粒，在半导体中，电子和空穴成为载流子。
有机电荷传输材料是一类当有载流子(电子或空穴)注入时，在电场作用下可以实现载流子的定向有序的可控迁移从而达到传输电荷的有机半导体材料，其包括偏空穴传输型(P型)材料和偏电子传输型(N型)材料两类。如形成所述发光子层的偏空穴传输型的材料包括：
DSA-ph(1，4-二[4-(N，N-二苯基)氨基]苯乙烯基苯)；
DNCA(N6，N6，N12，N12-四-甲基苯屈-6，12-二胺，偏甲苯屈)；
BDAVBi(4，4′-双[4-(二苯基氨基)苯乙烯基]联苯)；以及
N-BDAVBi等。
如形成所述发光子层的偏电子传输型的材料包括：
Alq3(三(8-羟基喹啉)铝)；
ADN(9，10-二(2-萘基)蒽)；
TBPe(1，4，7，10-四叔丁基二萘嵌苯)；以及
DPVBi([4，4′-(2，2-苯乙烯基)-1，1′-联苯])等。
当发光子层采用单极性材料时，假定其传输极性为第一极性(可以是N型，也可以是P型)，在本公开的具体实施例中，为了控制发光层内的不同极性的载流子的浓度比例，引入载流子控制层，由于其材料的传输极性与发光子层所采用的材料的传输极性相反，即二者具有相反的极性，因此能够通过控制二者之间的厚度差距以及间隔设置来控制发光层中的载流子的浓度比例。
例如，当发光层中的载流子的浓度比例达不到要求时，如需要提高发光层内电子的浓度比例时，则可以通过增加偏N型材料的厚度或者降低偏P型材料的厚度来提高发光层内电子的浓度比例，而需要提高发光层内空穴的浓度比例时，则可以通过增加偏P型材料的厚度或者降低偏N型材料的厚度来提高发光层内电子的浓度比例。
也就是说，本公开实施例中，所述第一材料为偏空穴传输型材料时，所 述第二材料为偏电子传输型材料；所述第一材料为偏电子传输型材料时，所述第二材料为偏空穴传输型材料，进而通过控制第一材料和第二材料形成的层状结构的厚度和层间隔方式来控制发光层中的载流子的浓度比例，即所述载流子的浓度比例根据发光子层的厚度、载流子控制的层厚度以及发光子层与载流子控制层的间隔方式设置。
示例二
在示例二中，通过对材料的选择，在发光层中形成一定的势垒，阻挡部分载流子继续深入到发光层内部，从而使得无法继续进入发光层内部的载流子在发光层中累积，形成载流子控制电场，进而通过该载流子控制电场来控制所述发光层内的不同极性的载流子的浓度比例。
形成上述的载流子控制电场可以通过第一材料和第二材料的最高占据分子轨道HOMO(Highest Occupied Molecular Orbital)与最低未占据空轨道LUMO(Lowest Unoccupied Molecular Orbital)来实现。
两种材料的最高占据分子轨道HOMO能级差会影响空穴的注入，而两种材料的最低未占据空轨道LUMO能级差则会影响电子的注入，HOMO能级差越大，则阻挡空穴的能力越强，而LUMO能级差越大，则阻挡电子的能力越强。
因此，当需要提高发光层内电子的浓度时，则可以选用LUMO能级与发光层材料的LUMO能级差距更小的材料作为载流子控制层，以减小LUMO能级差，加强电子的注入，提高发光层内电子的浓度。
而当需要提高发光层内空穴的浓度时，则可以选用HOMO能级与发光层材料的HOMO能级差距更小的材料作为载流子控制层，以减小HOMO能级差，加强空穴的注入，提高发光层内空穴的浓度。
对此举例说明如下。
如图2所示，为DNCA(N6，N6，N12，N12-四-甲基苯屈-6，12-二胺，偏甲苯屈)和BPhen(4，7-二苯基-1，10-邻二氮杂菲)的HOMO和LUMO的示意图。从图2中可以发现，DNCA的HOMO能级为-2.6eV，LUMO能级为-5.2eV，而Bphen的HOMO能级为-2.9eV，LUMO能级为-6.4eV，因此DNCA和Bphen之间的HOMO能级差只有0.3eV，即DNCA的HOMO能级(-2.6eV)与Bphen的HOMO能级(-2.9eV)的差值，相对较小，因此大量空穴能够克服上述的0.3eV的能级差在DNCA中传输并到达DNCA与Bphen的交界处。而对于电子而言，如果其需要穿过DNCA传并输到Bphen，则需要克服的LUMO能级 差为1.2eV，即DNCA的LUMO能级(-5.2eV)与Bphen的LUMO能级(-6.4eV)的差值)，这对于电子而言是非常大的能级差，很难克服，因此实现了电子的阻挡。
在本公开的具体实施例中，为了保证电子和空穴的浓度比例在1.5∶1～1∶1.5之间，当所述第一材料为偏空穴传输型时，所述第一材料与所述第二材料的HOMO能级差＞＝0.5eV，所述第一材料与所述第二材料的LUMO能级差应＜＝0.4Ev；当所述第一材料为偏电子传输型时，所述第一材料与所述第二材料的HOMO能级差＜＝0.5eV，所述第一材料与所述第二材料的LUMO能级差应＞＝0.1eV。也就是说，本公开实施例中，通过选择HOMO与LUMO分别满足一定关系的不同材料，即可在发光层内形成吸引或阻挡载流子的势垒，进而影响发光层内的不同极性的载流子的浓度比例。
至于采用何种材料来满足发光层内的不同极性的载流子的浓度比例可以通过不断的实验得到。
应当理解的是，上述的两种方式并不冲突，二者可以结合使用。
在本公开的具体实施例中，发光主要是由第一材料来实现，而由于增加了载流子控制层，为了使得本公开实施例增加的载流子控制层不对发光层产生的光线造成影响，一种示例性的实现方式是保证形成所述载流子控制层的第二材料的吸收光谱和形成所述发光子层的第一材料的发光光谱不重叠。
通过吸收光谱的控制，使得第一材料发出的光线不致被第二材料吸收，因此本公开实施例不会降低单色OLED的发光效率。
本公开具体实施例的单色OLED可以为各种颜色的荧光OLED，其中一种示例性的实现方式中，单色OLED为蓝光OLED，形成所述发光子层的第一材料为蓝色荧光染料。
所述蓝色荧光染料可以为蒽衍生物、苝衍生物、芘衍生物或芴衍生物。
所述蓝色荧光染料还可以是：DSA-ph(1，4-二[4-(N，N-二苯基)氨基]苯乙烯基苯)、BCzVBi(4，4′-双(9-乙基-3-咔唑乙烯基)-1，1′-联苯)、TBPe(1，4，7，10-四叔丁基二萘嵌苯)、DPVBi([4，4′-(2，2-苯乙烯基)-1，1′-联苯])、BDAVBi(4，4′-双[4-(二苯基氨基)苯乙烯基]联苯)或N-BDAVBi。本公开实施例还提供了一种单色OLED的制作方法，包括形成发光层的步骤，如图3所示，所述形成发光层的步骤中具体包括：
步骤301，形成至少一个发光子层；以及
步骤302，形成至少一个与所述发光子层相邻的载流子控制层，其中所 述载流子控制层用于控制所述发光层内的不同极性的载流子的浓度比例。
控制不同极性的载流子的浓度比例可以通过如下两种方式实现：
形成所述载流子控制层的第二材料和形成所述发光子层的第一材料具有相反的极性，以控制所述发光层内的不同极性的载流子的浓度；以及
所述第一材料和所述第二材料的HOMO满足第一预定关系，所述第一材料和所述第二材料的LOMO满足第二预定关系，以形成载流子控制电场，其中所述载流子控制电场用于控制所述发光层内的不同极性的载流子的浓度比例。
在制作整个LED的过程中，首先根据设计的掩膜版，将ITO层刻蚀成需要的图案，然后依次用有机溶剂、臭氧等对其基板进行清洗与处理。接着将ITO基板放入真空镀膜机内，当腔体内压强下降到2×10-4Pa时，在ITO层上依次进行空穴传输层、包括载流子控制层结构的发光层、电子传输层、电子注入层和阴极的蒸镀，最后用玻璃盖板对ITO面进行相应的封装即可。
为了保证荧光OLED的发光效率，形成所述载流子控制层的第二材料的吸收光谱和形成所述发光子层的第一材料的发光光谱不重叠。
为了实现上述目的，本公开实施例还提供了一种包括上述单色OLED的OLED显示面板。
下面对本公开实施例的荧光OLED进行实验验证如下。
示例三
现有技术制作的OLED A如下，依次包括ITO、NPB(N，N′-二苯基-N，N′-二(1-萘基)-1，1’-联苯-4，4′-二胺)(40nm)形成的空穴传输层、DPVBi(4，4′-二(2，2二苯乙烯基)-1，1′-联苯)(30nm)形成的发光层、BPhen(4，7-二苯基-1，10-邻二氮杂菲)(30nm)形成的电子传输层、LiF(氟化锂)(0.6nm)形成的电子注入层，以及Al(铝)(120nm)形成的阴极；
本公开实施例的一种OLED B如下，依次包括：依次包括ITO、NPB(40nm)形成的空穴传输层、DPVBi(10nm)形成的发光子层、DSA-Ph(1，4-二[4-(N，N-二苯基)-氨基]苯乙烯基苯)(5nm)形成的载流子控制层、DPVBi(20nm)形成的发光子层、BPhen(30nm)形成的电子传输层、LiF(0.6nm)形成的电子注入层，以及Al(120nm)形成的阴极；
本公开实施例的另一种OLED C如下，依次包括：依次包括ITO、NPB(40nm)形成的空穴传输层、DPVBi(20nm)形成的发光子层、DSA-Ph(5nm)形成的载流子控制层、DPVBi(10nm)形成的发光子层、BPhen(30nm)形成的电子 传输层、LiF(0.6nm)形成的电子注入层，以及Al(120nm)形成的阴极。
图4a所示，为上述3种OLED的电压-电流密度以及电压-亮度的试验数据对照图，从图4a中可以发现(其中图4a和图6中的箭头代表曲线对应的纵坐标轴所在的方向，即图4a和图6中，上方的一组曲线为电压-电流密度的曲线，而下方的一组曲线为电压-亮度的曲线)：相对于现有技术的OLED A，本公开实施例的OLED B和C在同样的驱动电压下能够达到更高的亮度。
图4b所示，为上述3种OLED的电流密度-电流效率的试验数据对照图，从图4b中可以发现：相对于现有技术的OLED A，本公开实施例的OLED B和C在同样的电流密度下能够达到更高的电流效率，电流效率的提升非常明显。
因此，综合来看，相对于现有技术的OLED A，本公开实施例的OLED B和C在同样的驱动电压下，能够达到更高的亮度和更高的电流效率，但三者的电流密度并没有显著差异。
示例四
现有技术制作的OLED A(n＝0，没有载流子控制层)如下，依次包括ITO、NPB(40nm)形成的空穴传输层、DNCA(20nm)形成的发光层、BPhen(30nm)形成的电子传输层、LiF(0.6nm)形成的电子注入层，以及Al(120nm)形成的阴极；
本公开实施例的一种OLED(n＝1，一层载流子控制层)如下，依次包括：依次包括ITO、NPB(40nm)形成的空穴传输层、DNCA(10nm)形成的发光子层、Alq3(三(8-羟基喹啉)铝)(5nm)形成的载流子控制层、DNCA(10nm)形成的发光子层、BPhen(30nm)形成的电子传输层、LiF(0.6nm)形成的电子注入层，以及Al(120nm)形成的阴极；
本公开实施例的另一种OLED(n＝2，两层载流子控制层)如下，依次包括：依次包括ITO、NPB(40nm)形成的空穴传输层、DNCA(7nm)形成的发光子层、Alq3(2.5nm)形成的载流子控制层、DNCA(7nm)形成的发光子层、Alq3(2.5nm)形成的载流子控制层、DNCA(7nm)形成的发光子层、BPhen(30nm)形成的电子传输层、LiF(0.6nm)形成的电子注入层，以及Al(120nm)形成的阴极；
图5所示，为上述3种OLED的电流密度-电流效率的试验数据对照图，从图5中可以发现：相对于现有技术的OLED(n＝0)，本公开实施例的OLED(n＝1，2)在同样的电流密度下具有更高的电流效率。
示例五
现有技术制作的OLED A(n＝0，没有载流子控制层)如下，依次包括ITO、NPB(40nm)形成的空穴传输层、DPVBi(30nm)形成的发光层、BPhen(30nm)形成的电子传输层、LiF(0.6nm)形成的电子注入层，以及Al(120nm)形成的阴极；
本公开实施例的一种OLED(n＝1，一层载流子控制层)如下，依次包括：依次包括ITO、NPB(40nm)形成的空穴传输层、DPVBi(15nm)形成的发光子层、BAlq(双(2-甲基-8-羟基喹啉-N1，O8)-(1，1′-联苯-4-羟基)铝)(5nm)形成的载流子控制层、DPVBi(15nm)形成的发光子层、BPhen(30nm)形成的电子传输层、LiF(0.6nm)形成的电子注入层，以及Al(120nm)形成的阴极；
本公开实施例的另一种OLED(n＝2，两层载流子控制层)如下，依次包括：依次包括ITO、NPB(40nm)形成的空穴传输层、DPVBi(10nm)形成的发光子层、BAlq(2.5nm)形成的载流子控制层、DPVBi(10nm)形成的发光子层、BAlq(2.5nm)形成的载流子控制层、DPVBi(10nm)形成的发光子层、BPhen(30nm)形成的电子传输层、LiF(0.6nm)形成的电子注入层，以及Al(120nm)形成的阴极；
本公开实施例的再一种OLED(n＝3，三层载流子控制层)如下，依次包括：依次包括ITO、NPB(40nm)形成的空穴传输层、DPVBi(7.5nm)形成的发光子层、BAlq(1.6nm)形成的载流子控制层、DPVBi(7.5nm)形成的发光子层、BAlq(1.6nm)形成的载流子控制层、DPVBi(7.5nm)形成的发光子层、BAlq(1.6nm)形成的载流子控制层、DPVBi(7.5nm)形成的发光子层、BPhen(30nm)形成的电子传输层、LiF(0.6nm)形成的电子注入层，以及Al(120nm)形成的阴极。
图6所示，为上述4种OLED的电压-电流密度以及电压-亮度的试验数据对照图，从图6中可以发现：相对于现有技术的OLED，本公开实施例的n＝1和n＝2的OLED在的电流密度和亮度均有所提升，这得益于发光层内电子传输能力的增强。同时采用BAlq作为载流子控制层时，DPVBi的HOMO能级与BAlq的HOMO能级相同，且BAlq的LUMO能级与BPhen的LUMO能级差0.1eV，这样便使各个不同的发光层中，空穴呈浓度递减现象。相反的，0.1eV的势垒利于电子从电子传输层进入到发光层，且BAlq本身较强的电子传输能力也利于电子在发光层中的传输，从而利于电子-空穴对的平衡，使器件的亮度增加。但随着载流子控制层数的增加，有机材料的界面层数也会相 应增加，这在一定程度上会引入成膜缺陷，不利于载流子的传输，降低器件的性能，所以在本器件中，n＝3时，器件的电流密度和亮度均有所下降。
因此本公开实施例中，载流子控制层的层数小于或等于2。
本公开实施例中，通过增加载流子控制层，使得发光层内的电子浓度和空穴浓度处于合适的比例，大大降低了无法复合形成激子的电子或空穴，提高了载流子的利用率，提高了OLED的性能。
同时，本公开实施例中，由于载流子控制层的增加，扩展了激子的复合区域，降低了激子浓度，从而减少了激子淬灭情况(即激子以热能方式回到基态)的发生，提高了激子以光能方式回到基态的比例，提高了OLED的性能。
以上所述为本公开较佳实施例，需要指出的是，对于本领域普通技术人员来说，在不脱离本公开所述原理的前提下，还可以作出若干改进和润饰，这些改进和润饰也应视为本公开保护范围。

Claims (20)

  1. 一种单色OLED，包括发光层，其中所述发光层包括：
    至少一个发光子层；以及
    至少一个与所述发光子层相邻的载流子控制层，其中所述载流子控制层用于控制所述发光层内的不同极性的载流子的浓度比例。
  2. 根据权利要求1所述的单色OLED，其中所述浓度比例约为1.5:1～1:1.5。
  3. 根据权利要求1或2所述的单色OLED，其中所述载流子控制层的数量为1层或2层。
  4. 根据权利要求1-3任一项所述的单色OLED，其中形成所述载流子控制层的第二材料和形成所述发光子层的第一材料具有相反的极性。
  5. 根据权利要求4所述的单色OLED，其中所述第一材料为偏空穴传输型材料时，所述第二材料为偏电子传输型材料；所述第一材料为偏电子传输型材料时，所述第二材料为偏空穴传输型材料。
  6. 根据权利要求1-5任一项所述的单色OLED，其中所述浓度比例根据所述发光子层的厚度、所述载流子控制层的厚度以及所述发光子层与所述载流子控制层的间隔方式设置。
  7. 根据权利要求1-6任一项所述的单色OLED，其中所述第一材料和所述第二材料的最高占据分子轨道满足第一预定关系，所述第一材料和所述第二材料的最低未占据空轨道满足第二预定关系，以形成载流子控制电场。
  8. 根据权利要求7所述的单色OLED，其中当所述第一材料为偏空穴传输型时，所述第一材料与所述第二材料的所述最高占据分子轨道的能级差>＝0.5eV，所述第一材料与所述第二材料的最低未占据空轨道的能级差<＝0.4Ev；当所述第一材料为偏电子传输型时，所述第一材料与所述第二材料的所述最高占据分子轨道的能级差<＝0.5eV，所述第一材料与所述第二材料的最低未占据空轨道的能级差>＝0.1eV。
  9. 根据权利要求1-8中任意一项所述的单色OLED，其中所述第二材料的吸收光谱和所述第一材料的发光光谱不重叠。
  10. 根据权利要求1-9中任意一项所述的单色OLED，其中所述单色OLED为蓝色荧光OLED。
  11. 根据权利要求10所述的单色OLED，其中所述蓝色荧光OLED使用 的蓝色荧光染料为蒽衍生物、苝衍生物、芘衍生物或芴衍生物。
  12. 根据权利要求10所述的单色OLED，其中所述蓝色荧光OLED使用的蓝色荧光染料为DSA-ph、BCzVBi、TBPe、DPVBI、N-BDAVBi或BDAVBi。
  13. 根据权利要求12所述的单色OLED，其中所述单色OLED具体包括：
    ITO层；
    NPB形成的空穴传输层；
    DPVBi形成的至少一个发光子层；
    DSA-Ph形成的至少一个载流子控制层；
    BPhen(30nm)形成的电子传输层；
    LiF(0.6nm)形成的电子注入层；以及
    Al形成的阴极；
    或者所述单色OLED具体包括：
    ITO层；
    NPB形成的空穴传输层；
    DNCA形成的至少一个发光子层；
    Alq3形成的载流子控制层；
    BPhen形成的电子传输层；
    LiF形成的电子注入层；以及
    Al(120nm)形成的阴极；
    或者所述单色OLED具体包括：
    ITO层；
    NPB形成的空穴传输层；
    DPVBi形成的至少一个发光子层；
    BAlq形成的至少一个载流子控制层；
    BPhen形成的电子传输层；
    LiF形成的电子注入层；以及
    Al形成的阴极。
  14. 一种制作单色OLED的方法，包括形成发光层的步骤，其中所述形成发光层的步骤中具体包括：
    形成至少一个发光子层；以及
    形成至少一个与所述发光子层相邻的载流子控制层，其中所述载流子控制层用于控制所述发光层内的不同极性的载流子的浓度比例。
  15. 根据权利要求14所述的方法，其中所述浓度比例约为1.5:1～1:1.5。
  16. 根据权利要求14或15所述的方法，其中形成所述载流子控制层的第二材料和形成所述发光子层的第一材料具有相反的极性。
  17. 根据权利要求16所述的方法，其中所述第一材料和所述第二材料的最高占据分子轨道满足第一预定关系，所述第一材料和所述第二材料的最低未占据空轨道满足第二预定关系，以形成载流子控制电场。
  18. 根据权利要求17所述的方法，其中当所述第一材料为偏空穴传输型时，所述第一材料与所述第二材料的所述最高占据分子轨道的能级差>＝0.5eV，所述第一材料与所述第二材料的最低未占据空轨道的能级差应<＝0.4Ev；当所述第一材料为偏电子传输型时，所述第一材料与所述第二材料的所述最高占据分子轨道的能级差<＝0.5eV，所述第一材料与所述第二材料的最低未占据空轨道的能级差应>＝0.1eV。
  19. 根据权利要求14-18任意一项所述的方法，其中所述第二材料的吸收光谱和所述第一材料的发光光谱不重叠。
  20. 一种OLED显示面板，包括权利要求1-13任意一项所述的单色OLED。
PCT/CN2015/072211 2014-11-07 2015-02-04 单色oled及其制作方法和oled显示面板 WO2016070503A1 (zh)

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CN107749442A (zh) * 2017-10-16 2018-03-02 京东方科技集团股份有限公司 Oled器件及其制备方法、显示装置
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