低压高效OLED器件的制备与性能的研究
发布时间：2018-09-12 07:25
【摘要】：在信息科技不断发展的今天,人们对高品质显示器的追求逐渐提高,而有机电致发光器件(OLEDs)的主动发光,面板发光,视角广,响应时间短,发光效率高,色域宽,工作电压低,器件厚度薄,可制成弯曲面板,制作工艺相对简单,成本低等特性,吸引了人们的广泛关注和研究。考虑到未来OLED的商品化应用,我们需要保证器件具有较低的驱动电压,并在此基础上能够获得较高的发光效率。因此,本论文从降低OLED器件电压以及提高器件效率两方面开展了以下的研究工作。具体内容如下:1、在空穴注入方面采用了P型掺杂方式,主要研究了掺杂空穴缓冲层F4-TCNQ:Mo O3优化浓度和厚度下对空穴注入、传输的作用。从能级角度,我们分析了P型掺杂空穴缓冲层,在减小空穴界面注入势垒,利于空穴载流子的注入,降低器件驱动电压上的效力。通过薄膜表面形貌的测量,F4-TCNQ:Mo O3薄膜表面相对平整,更有助于空穴的注入。当掺杂缓冲层的浓度为50%,厚度为2 nm时,最佳器件的发光效率得到很大提高,同时与对比器件相较,器件的启亮电压和驱动电压(亮度为1000 cd/m2时)分别降低了1 V和2.3 V。2、在电子注入方面,应用了高迁移率的C60作为电子传输层,分别与三种电子缓冲层Alq3、Bphen和TPBi相结合的分层注入、传输结构,并研究了该结构对器件的电压和效率等方面的影响。在高迁移率C60最优厚度的基础上分别对Alq3、Bphen和TPBi的电子缓冲层的厚度进行了优化,器件的发光性能有了提高。与不含电子缓冲层的器件相较,有C60/电子缓冲层的结构器件发光特性有了大的改善。说明引入C60/缓冲层的结构,可以让器件在低电压驱动下有良好的电子注入能力,且使得器件中电子与空穴的注入、传输能力达到了平衡,有效地提高了激子的复合几率,从而降低了效率的滚降,同时缓冲层的加入起到了对C60层的保护作用。3、结合上述两部分的工作,将P型掺杂缓冲层F4-TCNQ:Mo O3和分层注入的C60/Bphen组合到一起,制备了类PIN结构的OLED器件。当发光材料为Alq3时,类PIN型器件相比于传统结构的OLED器件的启亮电压降低了31.6%,驱动电压降低了35.9%,同时电流效率提高了94%,功率效率提高了近164%,实现了器件在低压驱动下的高效发光。此外,把发光材料更换为蓝光材料TC-1759后,发现该类PIN型OLED器件也能获得很好的低压高效性能,证实了这种类PIN结构应用的广泛性。
[Abstract]:With the continuous development of information technology, the pursuit of high quality displays has been gradually improved, while the active luminescence, panel luminescence, wide angle of view, short response time, high luminous efficiency, wide color gamut and low operating voltage of organic electroluminescent devices (OLEDs). Because of its thin thickness, it can be made into bending panel, the fabrication process is relatively simple and the cost is low, so it has attracted wide attention and research. Considering the commercial application of OLED in the future, we need to ensure that the device has a lower driving voltage, and on this basis, we can obtain higher luminous efficiency. Therefore, the following research work has been done in this thesis: to reduce the voltage of OLED devices and improve the device efficiency. The main contents are as follows: 1. In the cavity injection, P-type doping is adopted. The effect of the optimized concentration and thickness of the doped hole buffer layer F4-TCNQ:Mo O 3 on the hole injection and transport is studied. From the point of view of energy level, we analyze P-doped hole buffer layer, which can reduce the potential barrier at the hole interface, facilitate the hole carrier injection, and reduce the driving voltage of the device. The surface of F4-TCNQ: MoO3 thin film is relatively flat, which is more helpful for hole injection. When the concentration of the doped buffer layer is 50 and the thickness is 2 nm, the luminescence efficiency of the optimal device is greatly improved, and compared with the contrast device, The starting voltage and driving voltage (brightness is 1000 cd/m2) are reduced by 1 V and 2.3 V. 2, respectively. In electron injection, the high mobility C60 is used as the electron transport layer, and the layer injection is combined with three kinds of electronic buffer layers, Alq3,Bphen and TPBi, respectively. The effect of the structure on the voltage and efficiency of the device is studied. Based on the optimum thickness of C60 with high mobility, the thickness of electronic buffer layer of Alq3,Bphen and TPBi is optimized, and the luminescence performance of the device is improved. Compared with the devices without the electronic buffer layer, the luminescent characteristics of the devices with C60 / electronic buffer layer have been greatly improved. It is shown that the structure of C60 / buffer layer can make the device have good electron injection ability under low voltage drive, and make the electron and hole injection in the device achieve the balance of transmission ability, and effectively improve the recombination probability of exciton. In addition, the addition of buffer layer can protect the C60 layer. Combined with the above two parts, the P-doped buffer layer F4-TCNQ:Mo O 3 and the layered injected C60/Bphen are combined together to fabricate the PIN like OLED devices. When the luminous material is Alq3, Compared with the conventional OLED devices, the PIN type devices have a lower starting voltage of 31.6a, a lower driving voltage of 35.9. at the same time, the current efficiency is increased by 944.The power efficiency of the devices is improved by 164.The high efficiency of the devices under the low-voltage drive is realized. In addition, when the luminescent material is replaced by blue light material TC-1759, it is found that this kind of PIN type OLED device can also obtain good low voltage and high efficiency performance, which proves the wide application of this kind of PIN structure.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN383.1
[Abstract]:With the continuous development of information technology, the pursuit of high quality displays has been gradually improved, while the active luminescence, panel luminescence, wide angle of view, short response time, high luminous efficiency, wide color gamut and low operating voltage of organic electroluminescent devices (OLEDs). Because of its thin thickness, it can be made into bending panel, the fabrication process is relatively simple and the cost is low, so it has attracted wide attention and research. Considering the commercial application of OLED in the future, we need to ensure that the device has a lower driving voltage, and on this basis, we can obtain higher luminous efficiency. Therefore, the following research work has been done in this thesis: to reduce the voltage of OLED devices and improve the device efficiency. The main contents are as follows: 1. In the cavity injection, P-type doping is adopted. The effect of the optimized concentration and thickness of the doped hole buffer layer F4-TCNQ:Mo O 3 on the hole injection and transport is studied. From the point of view of energy level, we analyze P-doped hole buffer layer, which can reduce the potential barrier at the hole interface, facilitate the hole carrier injection, and reduce the driving voltage of the device. The surface of F4-TCNQ: MoO3 thin film is relatively flat, which is more helpful for hole injection. When the concentration of the doped buffer layer is 50 and the thickness is 2 nm, the luminescence efficiency of the optimal device is greatly improved, and compared with the contrast device, The starting voltage and driving voltage (brightness is 1000 cd/m2) are reduced by 1 V and 2.3 V. 2, respectively. In electron injection, the high mobility C60 is used as the electron transport layer, and the layer injection is combined with three kinds of electronic buffer layers, Alq3,Bphen and TPBi, respectively. The effect of the structure on the voltage and efficiency of the device is studied. Based on the optimum thickness of C60 with high mobility, the thickness of electronic buffer layer of Alq3,Bphen and TPBi is optimized, and the luminescence performance of the device is improved. Compared with the devices without the electronic buffer layer, the luminescent characteristics of the devices with C60 / electronic buffer layer have been greatly improved. It is shown that the structure of C60 / buffer layer can make the device have good electron injection ability under low voltage drive, and make the electron and hole injection in the device achieve the balance of transmission ability, and effectively improve the recombination probability of exciton. In addition, the addition of buffer layer can protect the C60 layer. Combined with the above two parts, the P-doped buffer layer F4-TCNQ:Mo O 3 and the layered injected C60/Bphen are combined together to fabricate the PIN like OLED devices. When the luminous material is Alq3, Compared with the conventional OLED devices, the PIN type devices have a lower starting voltage of 31.6a, a lower driving voltage of 35.9. at the same time, the current efficiency is increased by 944.The power efficiency of the devices is improved by 164.The high efficiency of the devices under the low-voltage drive is realized. In addition, when the luminescent material is replaced by blue light material TC-1759, it is found that this kind of PIN type OLED device can also obtain good low voltage and high efficiency performance, which proves the wide application of this kind of PIN structure.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN383.1
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相关期刊论文 前5条
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2 刘瑞;徐征;赵谡玲;张福俊;曹晓宁;孔超;曹文U，
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