Synthesis Of Anthracene Oligomers For Organic Functional Materials And Fabrication Of Its Field-effect Transistors

Recently,New study turns its direction to organic functional materials and its application which reflects the integration of subjects such as chemicals,materials,physicals and electronics,gradually,a new interdiscipline turns out -organic electronics.in the future,One of the most important unit device in organic electronics is Organic Field Effect Transistors. The continuous advent of new type functional materials enrich man's visual field and also bring birth to the research of organic photo-electronic devices .The Organic field-effect transistor (OFET) is the importance devices of organic electronic devices families, it is transistor device using organic semiconductor materials as active layers. OFET can be applied to many fields, such as the driver of the active matrix liquid crystal display and the active matrix organic display, organic sensor, memorizer, RFID, E-book and E-paper, et al., it attracts great interests and people attention, OFET has important values of research. This paper summarizes and introduces the research in my doctor period, accompanied by the national Natural Science Foundation of China(NO.60276026) and provincial Natural Science Foundation of Gansu (ZS031-A25-012-G). In this paper, we carry out our researches on OFET from the following aspects:Firstly, it summarizes the general evolution history and important applications of organic semiconductor, such as Organic Light-Emitting Diode (OLED), organic solar, organic laser, organic Photodetector, organic sensor, Organic field-effect transistor(OFET) et al., their development and actuality. Review 20 years history of OFET, introduce organic integrate circuit, discuss problem of OFET, and present research hotspot of OFET.This thesis discusses the device structure of OFET which includes four general structures and some especial structures. It sums up all kinds of OFET materials, including organic semiconductor, dielectric materials, electrode materials, underlay materials, et al., which have performance, characteristic and applications. It studies the operation principle of organic semiconductor electric-types in detail.This paper introduces and studies roundly the theory model of organic semiconductor carrier, analyze the distributing form of carriers in OFET,and deduces the electric current equation of OFETs. It researches the estimating method of field-effect mobility, on/off ratio of current and threshold voltage in OFET. It discusses the reason of contact resistance between organic semiconductor and metal electrode, and influences to the device characteristic.This thesis discusses the influences of the contact resistance and the growth status of gate to the device characteristic insulating layer and organic semiconductor, and solutions are put forward, respectively.This paper researches the technics and characteristic of anthacene film by X ray diffraction(XRD),scan electronic microscope(SEM),atom force microscope(AFM).The epoxy resin and polyimide are researched in film technics, characteristic of dielectric, anthracene OFETs using a epoxy resin gate dielectric layer and polyimide gate dielectric layer are fabricated, respectively. We probe into the possibility and feasibility of all-organic, low cost OFETs.The organic semiconductor material 9,9'-Bianthracene of high purity has been synthesized and purified. Its characteristics are investigated by FT-IR, 1HNMR, MS, element analysis, XRD and AFM. For the first time, the OFETs with the 9,9'-bianthracene as the active layer are fabricated and found to exhibit P-type characteristics. It can thus be concluded from this study that the oligomerization of a small semiconductor molecule could also be an effective way to expand a p system for developing high mobility organic semiconductors.This paper investigate the Surface of 9,9'-bianthracene /SiO₂ using Atomic Force Microscopy(AFM) and X-ray Photoelectron Spectroscopy(XPS). XPS analysis shows that the O element diffused from insulator was proved to great bearing on the shift of other elements, which may degrade the performance of OFET. SiO₂ produced by sputtering technology is more advantageous than that by thermal oxidation.