Synthesis And Characterization Of Novel Organic Small Molecules On Field-effect Transistor

Organic field-effect transistors (OFETs) have attracted great attention from both scientific and technological circles due to their applications in sensors, electronic paper, and radio-frequency identification tags (RFIDs). In particularly, the organic semiconductor materials get enormous development because of their advantages which can be fabricated at low-cost, easy tailor, over large areas and on flexible substrate. However, the lagged research of the n-type organic semiconductor materials blocks the development and application of OFETs. To develop the high performance organic semiconductor materials with n-type and ambipolar properity, a serial of novel two-dimensional molecules were designed and synthesized. The physical and chemical properties were investigated by UV-vis spectra, electrochemistry and TGA. The electronic performance was characterized by thin film transistors. The detailed contents are listed as follows:1. Firstly, a series of new organic compounds with cruciform configuration were designed and synthesized in which benzodithiophene (BDT) was used as the central unit. The results of UV-vis spectra and electrochemistry revealed that these materials had good oxidation stability. The results of TGA indicated that these materials had high thermal stability. The thin film transistors were fabricated by chemical vapor deposition methods based on these cruciform semiconductor materials, the electronic performance including mobility and on/off ratio etc. was measured under different temperature of deposition. The effect of modified groups on the properties was also explored.2. A new organic semiconductors based on the naphthalimide was designed and synthesized. Its photophysical and electrochemical properties were characterized by UV-vis spectra and electrochemistry. The results of HOMO/LUMO energy levels and bandgap indicated that this compound should possess ambipolar performance.