Design,Assembly,Properties,and Application Of Organic Semiconductor Materials

The application of organic electronic technology in different fields has received great attention since the discovery of the field-effect phenomenon of organic semiconductors in 1984.In 2000,Heeger and coworkers were awarded the Nobel Prize in Chemistry for the discovery of conducting polymers,which opened a new era of organic electronics.In various electronic devices,such as field-effect transistor,solar cell,memory,sensor,organic materials have emerged one after another and proven to have broad application prospects.Therefore,a thorough understanding and mastery of materials and devices is necessary for the development of organic electronics.In the past two decades,organic electronics has seen tremendous improvements in the performance of organic field-effect transistors（OFETs）,which is attributed to the advantages of organic transistor devices such as low cost and versatility.The active materials in OFETs are organic semiconductors（OSCs）,which can be either conjugated small molecules or conjugated polymers.In this thesis,several works have been carried out around the design and assembly of organic semiconductor materials and related applications,with the following three specific areas of research:1.Based on the supramolecular self-assembly strategy,the coronene-DTTCNQ charge-transfer complex was prepared,and its charge-transfer properties were investigated using a liquid-liquid interfacial precipitation method with polycyclic aromatic hydrocarbons（coronene）as the donor and DTTCNQ as the acceptor.Coronene-DTTCNQ cocrystal had a stoichiometric ratio of 1:1 and a mixed-stacked binary structure.The electron mobility of the single-crystal field-effect transistor based on the coronene-DTTCNQ micro-nanocrystal was 0.07 cm²V^-1s^-1,which was consistent with the energy level symmetry mismatch results obtained from theoretical calculations.This had good electrical properties to D-A complexes,further extending the PAH-based complexes system.2.A novel patterned dielectric layer method was designed to prepare a flexible pressure sensor based on a field-effect transistor using DPP-DTT as a semiconductor layer,PMMA as a dielectric layer,and DBCz-TCAF complex crystals as a channel filler.By filling the new charge transfer complex DBCz-TCAF crystals in the patterned PMMA layer,the I_D is greatly reduced while maintaining high capacitance.The flexible OFET-based pressure sensor prepared using this patterned dielectric layer achieves a sensitivity of 0.28 kpa^-1 with good air stability.Our results provide a new idea for the development of flexible pressure sensors and may be used for future practical electronic skin applications.3.Two new perylenimine derivatives were designed and synthesized,and the hydrogen atoms on the nitrogen atoms of both perylenimine units were replaced by 6-methylundecyl.PDI-lg60 is characterized by core[1,2]disulfide substitution and selenium cyclization,while epoxidized and monomer-substituted PDI-lg57 has an extended conjugated structure and a distorted conjugated backbone.The performance of n-type organic thin-film transistor devices based on PDI-lg60 can reach up to 0.001 cm²V^-1s^-1 after thermal annealing.Further analysis illustrates that thermal annealing as well as the distorted conjugate backbone of the polymer significantly affects the crystallinity,grain size and n-channel charge transport behavior of the films.