基于石墨烯/聚合物复合介质层的交流OLED研究

Although the alternating current driven OLEDs (AC OLEDs) possess the advantages of simple driving and good stability, but there are some issues such as high operating voltage, low brightness and low power efficiency, which need to be addressed to meet the requirements for practical application. In this project, the research on AC OLEDs will be carried out. The graphene/polymer composites with high dielectric constant will be developed by the photocatalytic reduction of graphite oxide and the ultrasonic exfoliation of graphene assisted with surfactant. And the resulting graphene/polymer composites will be proposed to be used as the dielectric layer in the AC OLEDs to replace the conventional metal oxides and polymers with relatively low dielectric constant. The charge generation layer based on the organic heterojunction (OHJ) is designed to be inserted between the dielectric layer and the electroluminescence unit. It is hoped that the introduction of graphene/polymer dielectric layer and OHJ charge generation layer can reduce the operating voltage and improve the brightness and power efficiency in the AC OLEDs. In addition, the study on the mechanism will be carried out, and the basic physical process of AC electroluminescence should be understood, which is helpful for further improve the performance of AC OLEDs by optimizing the device structures.

虽然交流OLED具有驱动简单和稳定性好等优点，但是目前仍然需要解决工作电压高、发光亮度低和功率效率差等问题，才能满足应用要求。本项目将开展交流OLED研究，拟采用光催化还原氧化石墨和表面活性剂辅助超声剥离石墨烯两种方法来制备具有高介电常数的石墨烯/聚合物复合材料，用这种复合材料代替金属氧化物和聚合物作为交流OLED的介质层，并通过在介质层与发光单元之间引入有机半导体异质结作为电荷产生层，希望能够降低交流OLED的工作电压，提高发光亮度和功率效率。此外，本项目还将研究这种基于石墨烯/聚合物介质层结构的交流OLED的发光机理，弄清其中交流电致发光的基本物理过程，为进一步优化交流OLED的结构和性能提供理论依据。

本项目围绕交流OLED开展了以下四个方面的研究：1）石墨烯/聚合物复合介电薄膜研究；2）有机半导体异质结电荷产生层研究；3）OLED的器件结构与发光性能研究；4）交流OLED发光器件与机理研究。我们开发出具有较高介电常数的石墨烯/聚合物复合材料与薄膜，结合石墨烯/聚合物介电层与有机半导体异质结制备出具有较高发光性能的交流OLED器件，还开发出具有双向发光特性的叠层交流OLED器件，实现了交流OLED发光颜色的可控调节。本项目发表SCI论文4篇，申请中国发明专利6项，授权中国发明专利1项；培养研究生3名，其中毕业博士生2名，在读硕士生1名。