Investigation On The Design, Synthesis And Properties Of A Novel Electronic Transporting Materials Containing Fluorine

Novel materials are the bases of New Scientific and Technical Revolution.With the rapid developments of organic optoelectronic devices,such as organic solar cells,organic light-emitting diodes and organic field-effect transistors,et al.,organic n-type semiconductors with high mobility,good stability and facile processing ability are in dire need.Thereby,basing on molecule and material designs,new kind of n-type electronic transporting materials triphemodioxazine derivatives were discovered,and strong electron-withdrawing trifluoromethyl group and F atom were introduced to its aromatic core, perfluoroalkyl group was introduced in the molecular structure of a kind of traditional organic n-type material,naphthalene diimide.The effects of the fluorination on energy levels, solubility and stability of naphthalene diimide were studied.With aniline and 2-aminophenol as starting material,the triphemodioxazine derivatives A1-A6 were synthesized.The influence of the fluorination on the energy levels was investigated.Cyclic voltammetry(CV) and UV-Vis absorption measurements were performed and the LUMO energy levels was calculated.The results indicated that introducing fluorine groups lowered the LUMO energy level.According to the study of intermolecular interactions and crystal packing,it suggests that the close face-to-face p-p stacking lies in the direction normal to the molecular plane and it could give rise to efficient charge carrier transport and prevent O₂ intrusion which could be responsible for high stability of these OFET devices.The best OFETs based on A1 and A2 showed a mobility of 0.07 cm²/V·s and 0.03 cm²/V·s.With 1,4,5,8-naphthalene tetracarboxylic dianhydride as starting material,through esterification,bromination,fluorination,hydrolyzation and imidization,perfluoroalkyl groups were introduced to the naphthalene core at the 2-and 2,6-position.The introduction of alkyl group in N atom results in impressive improvements of the solubility.The LUMO energy level is lowered by 0.35 eV because of the fluorination.The liquid-crystalline behaviors of B3 and B6 were investigated by differential scanning calorimetry(DSC) and polarizing optical microscopy(POM).Preliminary tests show that they will be promising n-type materials.