Effect of trifluoromethyl modification on photoelectric properties of materials

In the field of materials science, trifluoromethyl (-cf ₃) modification has become an important means to control the photoelectric properties of materials. By introducing -cf ₃ into organic light emitting diodes (OLEDs), liquid crystal materials or polymers, the photoelectric properties of the materials can be significantly improved, which provides a new way for the development of high-performance photoelectric materials. 

In OLED materials, the introduction of trifluoromethyl can effectively adjust the electron cloud distribution and energy level structure of molecules. Due to the strong electron absorption characteristics of trifluoromethyl, it can reduce the highest occupied molecuLar orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels of molecules, promote electron injection and transmission, and improve the luminous efficiency and stability of OLED devices. At the same time, the existence of trifluoromethyl can also enhance the interaction between molecules, inhibit the aggregation and crystallization of molecules, and reduce the efficiency roll off phenomenon of devices. The experimental results show that the devices made of trifluoromethyl containing OLED materials can still maintain high luminous efficiency under high brightness, which has a good application prospect. 

For liquid crystal materials, trifluoromethyl modification can significantly affect the phase behavior and orientation properties of liquid crystal molecules. The strong electronegativity of Fluorine atoms enhances the dipole dipole interaction between molecules, which makes the liquid crystal materials have a wider liquid crystal phase temperature range and faster response speed. In addition, the low surface energy of trifluoromethyl is helpful to improve the orientation uniformity of liquid crystal molecules, and improve the contrast and viewing angle performance of liquid crystal display devices. In polymer materials, the introduction of trifluoromethyl can give the material excellent optical transparency, thermal stability and chemical stability, which makes it have important application value in optoelectronic device packaging, optical film and other fields.