【作者】 徐达；

【导师】 于军胜；

【作者基本信息】 电子科技大学 ， 光学工程， 2022， 硕士

【摘要】 有机电致发光器件（Organic light-emitting devices,OLED）由于其亮度高、可柔性、自发光和能耗小等优点而受到研究者们的广泛关注并被应用诸如OLED显示面板、OLED照明灯以及可穿戴设备等领域中。本工作通过将多孔纤维柔性压阻层集成至柔性OLED器件上制备触控响应器件,利用“人/机可读的视觉输出”的方法来进行环境压力测量,避免了数据收集、数据传输以及数据处理和显示这个复杂的过程,可以应用在电子皮肤、医疗检测、人机交互界面等领域。与传统的硅基材料制备的压力传感器相比,该器件具有轻柔、易穿戴、贴合度高等优势,将OLED应用在可穿戴领域是未来发展的趋势。本工作的研究内容主要分为以下两个部分:（1）首先,本工作制备了柔性高亮度绿光OLED器件,并基于多壁碳纳米管（Carbon Nanotubes,CNTs）溶液和纤维组织制备压阻层,由于基底的天然多孔结构和表面高斯分布,该压阻层具备较高的灵敏度(（29）1400 k Pa^-1)和较快的响应时间（（27）10 ms）。并基于柔性OLED器件和压阻层制备了触控响应器件。此外本工作还研究了外部压力对OLED内部结构的影响,我们发现外部压力会改变OLED内部材料的孔隙比,提高材料的接触面积和器件的电流密度,从而影响到器件的发光亮度。经过200 k Pa处理10 min后,器件亮度从25600 cd·m^-2提高到30200 cd·m^-2,表明触控响应器件亮度随外部压力改变的现象是由压阻层的分压变化和OLED内部电流密度变化两方面共同作用引起的。制备得到的触控响应器件不仅能在较小压强下实现快速高亮度响应,并且还具有线性度高、稳定性高等优势。（2）通过向CNTs溶液中掺杂MXene材料,利用一维材料和二维材料之间的协同效应来进一步提高器件灵敏度和响应时间,并研究了碳化钛（Ti₃C₂T_x）的掺杂浓度对压阻层的性能影响。其中10 wt%Ti₃C₂T_x掺杂的CNTs溶液制备的压阻层灵敏度最高,达到1861 k Pa^-1,相较于CNTs溶液制备的压阻层,最终实现灵敏度提高30%左右,响应时间也略有提升。并基于此压阻层制备了白光触控响应器件,相较于对比组,制备的触控响应器件在10 k Pa压强下的亮度响应提高了22%左右,进一步提升了其器件性能和应用范围。综上所述,本工作基于OLED发光膜和多孔纤维柔性压力传感器制备了柔性触控响应器件,最终实现了对外部压力的准确探测和无线传输,为压力可视化器件的应用打下了基础,该器件可运用于健康检测、人机交互识别和智能服装等领域。更多还原

【Abstract】 Organic light emitting devices（OLED）have attracted extensive attention and been applied to various fields because of their high brightness,flexibility,self luminescence and low energy consumption.Such as OLED display panel and OLED lighting,but there are relatively few applications of OLED in wearable devices.In this paper,the porous fiber flexible piezoresistive layer is integrated on the flexible OLED device,which can realize the method of“human/machine-readable visual output”to measure the environmental pressure,avoiding the complex process of data collection,data transmission,data processing and display.It can be widely used in electronic skin,medical detection,human-computer interface and so on.Compared with the traditional pressure sensor made of silicon-based materials,it has the advantages of softness,easy to wear and high fit.The application of OLED in the wearable field is the development trend in the future.The research content of this paper is mainly divided into the following two parts:（1）First,a flexible high-brightness green OLED device was prepared,and a piezoresistive layer was prepared based on the multi-walled carbon nanotube solution and fibrous tissue.Due to the natural porous structure and surface Gaussian distribution of the substrate,the prepared piezoresistive layer has high sensitivity(（29）1400 k Pa^-1)and fast response time（（27）10 ms）.We found that the external pressure will change the porosity of the material inside OLED,improve the contact area and current density,and affect the luminous brightness of OLED.After 10 min treatment at 200 k Pa,the brightness of the device will increase from 25600 cd·m^-2 to 30200 cd·m^-2,indicating that the change of the brightness of the prepared touch response device with the external pressure is caused by the joint action of the partial pressure of the piezoresistive layer and the change of the internal contact area of the OLED.The prepared touch response device can not only achieve fast and high brightness response under low pressure,but also has the advantages of high linearity and high stability.（2）By doping titanium carbide into carbon nanotube solution,the synergistic effect between one-dimensional and two-dimensional materials is used to further improve the sensitivity and response time of the device,and the effects of different concentrations of titanium carbide doping on the properties of piezoresistive layer are studied.The piezoresistive layer prepared based on 10 wt%Ti₃C₂T_x doped carbon nanotube solution has a sensitivity of 1861 k Pa^-1.Compared with the devices prepared based on carbon nanotube solution,the final sensitivity is improved by about 30%and the response time is slightly improved.The white light touch response device is prepared based on this piezoresistive layer.Compared with the device based on carbon nanotube,the brightness response of the touch response device prepared by doping titanium carbide increases by about 22%under the pressure of 10 k Pa,which further improves its device performance and application range.In summary,this work prepared a flexible touch response device based on OLED light-emitting film and porous fiber flexible pressure sensor,and finally realized the accurate detection and wireless transmission of external pressure.This research can be applied to the fields of health detection,human-computer interaction recognition and smart clothing,and expanded the application of OLED in wearable devices.更多还原