Fabrication And Characterization Of Organic Field Effect Transistors Based On Novel Small Molecules

Recently, organic electronics as a newly emerging important research field,achieved rapid development. As the main component of flexible circuits, organic field effect transistors(OFETs), have wide used in sensors, electronic paper, and radio-frequency identification tags(RFIDs). On the other hand, although scientists have made some forecast about the relationship between the structure of organic semiconductors molecular and field-effect transistor charge transfer, the charge transport mechanism and the relationships among the chemical structures, molecular arrangements and electronic properties are still unclear. It is important to explore new organic semiconductor materials and device fabrication methods for development of organic field-effect transistors. In this article, our research focused on the fabrication of thin film and single crystal field-effect transistors based on three kinds of novel organic semiconductor materials. The main results are summarized as following:1. Firstly, the two-dimensional starphene BTBTT was synthesized and its physical and chemical properties were characterized. The thin film field-effect transistors based on the two-dimensional fused-ring compound BTBTT were fabricated by vapor evaporation, and the highest mobility is 2.46x10-2cm2/Vs when deposited at 60℃.Furthermore, the single crystalline microribbons of BTBTT were prepared by physical vapor transportation. The single crystalline transistors based on the BTBTT microribbons were also fabricated and the devices exhibit high performance and the mobility is 0.56cm2/Vs.2. The two-dimensional fused-ring compound 4TBT was synthesized and which isnot only central symmetry but also axial symmetry. The thin film transistors devices were fabricated by vapor evaporation method at different substrate temperature and the results show that the temperature of substrate can greatly affect the devices performance.The highest mobility is 1.41x10-2 when deposited at 60℃.3. The thin films of 4BTTT were prepared at different substrate temperature by vapor evaporation. Then the field-effect transistors of 4BTTT were fabricated through evaporation of gold electrodes with copper mask. The measurement results show that the temperature of substrate can greatly affect the molecular arrangement as well as the devices performance and the highest mobility of 2.03x10-2 cm2/Vs was obtained when deposited at 60℃.