Design And Fabrication Of Anthracene Derivative-based Blue Organic Light-emitting Diodes And Their Applications In Bioelectronic Device

Organic light-emitting diode(OLED)is known as“dream display technology”for it has many advantages,such as fast response,low energy consumption,active light-emitting,great flexibility and so on.At present,OLEDs have been widely used in the field of consumer electronics.However,among the three primary colors(red,green and blue),blue light requires the widest energy gap(eg>0.3 e V),which is not easy to achieve in organic luminescent materials.So it brings more challenge in the design and synthesis of blue luminescent materials.Consequently,blue light OLEDs have always been the"weak point"in the development of OLEDs.In order to further improve the competitiveness of OLED in illumination and display market,it is necessary to develop blue OLED materials and devices.In addition to improve OLEDs through the material innovation and device engineering,the combination of new concepts and interdisciplinary to expand the application of OLED also helps to promote the progress of OLED technology and the development of related industries.Therefore,in ths paper,we focus on the new materials and new applications of blue OLED,followings are detailed research contents.1.In chapter 2,we designed and synthesized three blue luminescent molecules of anthracene derivatives with Aggregation-induced emission(AIE)effect.In view of the different degrees of fragmentation of these molecules in the NMR spectrum,we combined theoretical calculations to predict and analyze the stable conformations that may exist in the molecules.On this basis,the photophysical properties,thermal properties,electronic properties,and electrochemical properties of these molecules were characterized.The analysis and comparison of the physical and chemical properties of molecules in single stable conformation and double stable conformation are compared.Afterwards,non-doped OLED devices of these molecules were prepared and characterized,and the types of hole injection layers of the devices were optimized.The results show that the molecules with double stable conformation can avoid the phenomenon of crystallization in the process of thermal evaporation deposition and under the working conditions of the device,which is beneficial to improve the morphological stability of the light-emitting layer of the device and obtain higher device efficiency.Finally,the theory of grain boundary energy trap was introduced to explain the relationship among the difference in device performance,thermal stability of molecules and molecular conformation.2.In chapter 3,we attempted to use flexible blue OLED as the light source,conjugated polymer PPV-NMe₃⁺,which is dispersed in sodium alginate hydrogel,as the photosensitizer.Intergating the encapsulated OLED and the hydrogel into a new bioelectronic device,which is able to generate reactive oxygen species(ROS)to kill bacteria.Based on this idea,we first synthesized a new anthracene derivative with deep blue emission and fabricated its OLED device on a flexible PET substrate.The emission wavelength of the device is 443 nm and its FWHM is 55 nm,which has a large overlap range with the absorption wavelength of the conjugated polymer.The OLED was simply encapsulated with a UV-cured silicone elastomer,and the encapsulated device can work normally in solution for at least 15 minutes.Morover,the physico-chemical properties of the conjugated polymer hydrogel were characterized.Finally,the conjugated polymer hydrogel was attached to the encapsulated OLED to obtain a photodynamic antibacterial bioelectronic device.In vitro antibacterial experiment shows that the device has obvious killing effect on both gram positive and gram negative bacteria and this antibacterial strategy can avoid bacterial resistance,which provides a new idea to solve the problem of bacterial resistance.