叠层式有机发光二极管的电荷产生层及界面的研究
发布时间：2019-07-02 20:30
【摘要】：有机发光二极管(OLED)以其自发光,对比度大,视角广,响应时间快和工作温度范围宽的特点已被成功地应用于平板显示领域。为了降低显示面板的制造成本,大尺寸化是当前OLED技术应用的发展趋势。大尺寸OLED面板的全彩色显示采用白光OLED(WOLED)与彩色滤光片组合的方式,其中WOLED为叠层式OLED,即由多个发光单元在垂直方向上用电荷产生层连接而成。相比传统OLED,叠层式OLED的应用可提高面板的发光效率和工作寿命,降低面板的短路几率。电荷产生层是叠层式OLED的核心,其电荷产生与分离效率,工作稳定性,透光性以及制备工艺关系到器件乃至整个面板的效率,寿命和成本。论文以发展用于大尺寸OLED显示面板的高效稳定的叠层式器件为目标,从结构,机理,材料和工艺方面对叠层式OLED的电荷产生层及界面做了深入的研究。首先,针对传统有机n/p掺杂型电荷产生层的稳定性差和工艺复杂的问题,论文提出了基于有机p型掺杂层NPB:F4-TCNQ和超薄电子注入层Liq/Al的综合性能优异的新型电荷产生层Liq/Al/NPB:F4-TCNQ,电荷产生与分离效率高,可见光区域透光率超过90%,长期工作稳定性高,且制备工艺简单。通过对电荷产生与分离的机理研究,发现提高Al的蒸镀速率,F4-TCNQ的掺杂浓度,以及增加界面层可以促进能级匹配,降低电荷分离能垒,获得优化的电荷产生层liq/al/f4-tcnq/npb:f4-tcnq。将该电荷产生层应用于基于蒸镀和溶液法工艺的叠层式woled,不仅降低了woled的制备成本,而且可以通过改变有机p型掺杂层的厚度调节woled的光色。其次,针对n型铟镓锌氧化物薄膜晶体管与倒置式oled结合用于大尺寸显示面板的特点,论文着重研究了传统的单发光单元的和叠层的倒置式oled的效率和稳定性。传统电子注入层cs2co3易被空气氧化,电子注入稳定性差,而论文提出的新型电子注入层al/cs2co3,通过简单地插入一层超薄的al,与cs2co3形成稳定的al-o-cs化合物,大幅提高了倒置式oled的稳定性。针对叠层的倒置式oled的特点,论文提出了采用非掺杂型p/n异质结moo3/al/cs2co3的电荷产生层,其中的p型组件采用moo3与咔唑类主体材料的搭配,可同时又作为空穴传输层,简化了叠层式器件结构;中间1nm的插层al可显著提高电荷产生层的电荷分离能力与稳定性,这主要是由于插层al可以有效地防止cs2co3与moo3发生化学反应形成耗尽层。最后,由于溶液法工艺相比热蒸镀工艺更易于实现大尺寸化且可柔性化的面板,论文对基于溶液法制备电荷产生层及叠层式oled器件的关键性问题做了探索性研究,包括空穴注入层和电子注入层的溶液法制备,以及电荷产生层的溶液法工艺。空穴注入层由moo3粉末直接溶解在氨水中形成的澄清透明溶液,旋涂后在空气中经150°C低温退火形成薄膜。此空穴注入层具有纳米柱状结构,可以获得比PEDOT:PSS和蒸镀的MoO3更好的空穴注入能力。另一种空穴注入材料是由HATCN溶解在乙腈溶剂中形成的透明溶液,采用该溶液制的薄膜也具有较强的空穴注入能力。电子注入层是由ZnO粉末与甲酸在氨水催化作用下制备而成,在空气中经低温退火后具有很强的电子注入能力。X射线单晶衍射等结果表明薄膜中形成了金属-有机骨架(MOF)[(H3O)Zn(HCOO)3]∞,具有强电负性和吸电子性的甲酸根吸附在电极表面,形成指向MOF薄膜的偶极子,降低了电极的表面功函数。以MOF[(H3O)Zn(HCOO)3]∞与PEIE混合作为n型组件,HATCN的乙腈溶液为p型组件,实现了溶液法电荷产生层MOF:PEIE/HATCN。电荷注入层和电荷产生的溶液法工艺,不仅降低了OLED的制备成本,而且在其他有机电子器件中也具有广阔的应用。
[Abstract]:The organic light-emitting diode (OLED) has been successfully applied to the field of flat panel display with its self-luminescence, high contrast, wide viewing angle, fast response time and wide operating temperature range. In order to reduce the manufacturing cost of the display panel, the large-size is the developing trend of the current OLED technology application. The full color display of the large-size OLED panel is in the form of a white light OLED (WOLED) and a color filter, wherein the WOLED is a stacked OLED, that is, a plurality of light emitting units are connected in a vertical direction with a charge generating layer. Compared with the traditional OLED, the application of the laminated OLED can improve the light-emitting efficiency and the working life of the panel, and reduce the short-circuit probability of the panel. The charge generation layer is the core of the laminated OLED, and the charge generation and separation efficiency, the working stability, the light transmission and the preparation process are related to the efficiency, the service life and the cost of the device and the whole panel. In order to develop a highly effective and stable laminated device for large-size OLED display panel, the charge generation layer and the interface of the laminated OLED are studied in terms of structure, mechanism, material and process. First, a novel charge generation layer Liq/ Al/ NPB: F4-TCNQ with excellent comprehensive performance of the organic p-type doped layer NPB: F4-TCNQ and the ultra-thin electron injection layer Liq/ Al is proposed for the problems of poor stability and complex process of the conventional organic n/ p-doped type charge generation layer, and the charge generation and separation efficiency are high, The light transmittance of the visible light region is more than 90 percent, the long-term working stability is high, and the preparation process is simple. By studying the mechanism of charge generation and separation, it is found that increasing the deposition rate of Al, the doping concentration of F4-TCNQ, and increasing the interface layer can promote the energy level matching, reduce the charge separation energy base, and obtain the optimized charge generation layer liq/ al/ f4-tcnq/ npb: f4-tcnq. The application of the charge generation layer to a laminated type wled based on a vapor deposition and solution process process not only reduces the cost of preparation of the wled, but can adjust the light color of the oled by changing the thickness of the organic p-type doped layer. In this paper, the efficiency and stability of the conventional single-light-emitting unit and the laminated inverted-type oled are studied in this paper, for the characteristics of the n-type zinc-doped zinc oxide thin film transistor and the inverted-type oled for large-size display panel. The conventional electron injection layer cs2co3 is easily oxidized by air and the stability of the electron injection is poor, and the novel electron injection layer al/ cs2co3 proposed in the paper can form a stable al-o-cs compound with the cs2co3 by simply inserting a layer of ultra-thin al, and the stability of the inverted oled is greatly improved. In this paper, a charge generation layer with a non-doped p/ n heterojunction moov 3/ al/ cs2co3 is proposed in this paper. The p-type component is used with the combination of the moo3 and the bulk material, and can be used as the hole transport layer at the same time, and the structure of the stacked device is simplified. The intercalation al at the middle of 1 nm can significantly improve the charge separation ability and stability of the charge-generating layer, which is mainly due to the fact that the intercalation al can effectively prevent the c2co3 and the moo3 from being chemically reacted to form a depletion layer. In the end, due to the fact that the process of the solution process is easier to realize the large-size and flexible panel compared with the hot-vapor deposition process, the key problem of the charge generation layer and the laminated-type oled device prepared on the basis of the solution method is explored, Includes a hole injection layer and an electron injection layer, and a solution process process of the charge generation layer. The hole injection layer is directly dissolved in the clear transparent solution formed in the ammonia water by the moo3 powder, and the film is formed at a low temperature of 150 DEG C in the air after spin coating. The hole injection layer has a nano-columnar structure, and a better hole injection capability than that of the PEDOT: PSS and the vapor-deposited MoO3 can be obtained. The other hole injection material is a transparent solution formed by dissolving the HATCN in an acetonitrile solvent, and the film prepared by the solution also has a strong hole injection capability. The electron injection layer is prepared from ZnO powder and formic acid under the action of ammonia water, and has strong electron injection capability after low-temperature annealing in air. The results of X-ray single crystal diffraction show that the metal-organic framework (MOF)[(H3O) Zn (HCOO)3] is formed in the film, and a strong electronegativity and electron-absorbing formate is adsorbed on the surface of the electrode to form a dipole which is directed to the MOF film, and the surface work function of the electrode is reduced. The solution method charge generation layer MOF: PEE/ HATCN is realized by mixing the MOF[(H3O) Zn (HCOO)3] and the PEE as n-type components and the acetonitrile solution of the HATCN as the p-type component. The process of the charge injection layer and the charge generation solution method not only reduces the preparation cost of the OLED, but also has a wide application in other organic electronic devices.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN383.1
，
本文编号：2509209
[Abstract]:The organic light-emitting diode (OLED) has been successfully applied to the field of flat panel display with its self-luminescence, high contrast, wide viewing angle, fast response time and wide operating temperature range. In order to reduce the manufacturing cost of the display panel, the large-size is the developing trend of the current OLED technology application. The full color display of the large-size OLED panel is in the form of a white light OLED (WOLED) and a color filter, wherein the WOLED is a stacked OLED, that is, a plurality of light emitting units are connected in a vertical direction with a charge generating layer. Compared with the traditional OLED, the application of the laminated OLED can improve the light-emitting efficiency and the working life of the panel, and reduce the short-circuit probability of the panel. The charge generation layer is the core of the laminated OLED, and the charge generation and separation efficiency, the working stability, the light transmission and the preparation process are related to the efficiency, the service life and the cost of the device and the whole panel. In order to develop a highly effective and stable laminated device for large-size OLED display panel, the charge generation layer and the interface of the laminated OLED are studied in terms of structure, mechanism, material and process. First, a novel charge generation layer Liq/ Al/ NPB: F4-TCNQ with excellent comprehensive performance of the organic p-type doped layer NPB: F4-TCNQ and the ultra-thin electron injection layer Liq/ Al is proposed for the problems of poor stability and complex process of the conventional organic n/ p-doped type charge generation layer, and the charge generation and separation efficiency are high, The light transmittance of the visible light region is more than 90 percent, the long-term working stability is high, and the preparation process is simple. By studying the mechanism of charge generation and separation, it is found that increasing the deposition rate of Al, the doping concentration of F4-TCNQ, and increasing the interface layer can promote the energy level matching, reduce the charge separation energy base, and obtain the optimized charge generation layer liq/ al/ f4-tcnq/ npb: f4-tcnq. The application of the charge generation layer to a laminated type wled based on a vapor deposition and solution process process not only reduces the cost of preparation of the wled, but can adjust the light color of the oled by changing the thickness of the organic p-type doped layer. In this paper, the efficiency and stability of the conventional single-light-emitting unit and the laminated inverted-type oled are studied in this paper, for the characteristics of the n-type zinc-doped zinc oxide thin film transistor and the inverted-type oled for large-size display panel. The conventional electron injection layer cs2co3 is easily oxidized by air and the stability of the electron injection is poor, and the novel electron injection layer al/ cs2co3 proposed in the paper can form a stable al-o-cs compound with the cs2co3 by simply inserting a layer of ultra-thin al, and the stability of the inverted oled is greatly improved. In this paper, a charge generation layer with a non-doped p/ n heterojunction moov 3/ al/ cs2co3 is proposed in this paper. The p-type component is used with the combination of the moo3 and the bulk material, and can be used as the hole transport layer at the same time, and the structure of the stacked device is simplified. The intercalation al at the middle of 1 nm can significantly improve the charge separation ability and stability of the charge-generating layer, which is mainly due to the fact that the intercalation al can effectively prevent the c2co3 and the moo3 from being chemically reacted to form a depletion layer. In the end, due to the fact that the process of the solution process is easier to realize the large-size and flexible panel compared with the hot-vapor deposition process, the key problem of the charge generation layer and the laminated-type oled device prepared on the basis of the solution method is explored, Includes a hole injection layer and an electron injection layer, and a solution process process of the charge generation layer. The hole injection layer is directly dissolved in the clear transparent solution formed in the ammonia water by the moo3 powder, and the film is formed at a low temperature of 150 DEG C in the air after spin coating. The hole injection layer has a nano-columnar structure, and a better hole injection capability than that of the PEDOT: PSS and the vapor-deposited MoO3 can be obtained. The other hole injection material is a transparent solution formed by dissolving the HATCN in an acetonitrile solvent, and the film prepared by the solution also has a strong hole injection capability. The electron injection layer is prepared from ZnO powder and formic acid under the action of ammonia water, and has strong electron injection capability after low-temperature annealing in air. The results of X-ray single crystal diffraction show that the metal-organic framework (MOF)[(H3O) Zn (HCOO)3] is formed in the film, and a strong electronegativity and electron-absorbing formate is adsorbed on the surface of the electrode to form a dipole which is directed to the MOF film, and the surface work function of the electrode is reduced. The solution method charge generation layer MOF: PEE/ HATCN is realized by mixing the MOF[(H3O) Zn (HCOO)3] and the PEE as n-type components and the acetonitrile solution of the HATCN as the p-type component. The process of the charge injection layer and the charge generation solution method not only reduces the preparation cost of the OLED, but also has a wide application in other organic electronic devices.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN383.1
，
本文编号：2509209
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