Studies Of Fabrication And Performance Of Organic Field-effect Transistors Based On Novel Structures

In recent years,with the advantages of low-cost,large-scale and mechanically flexible,organic semiconductor materials have great potential in flexible electronics.At present,field-effect transistors based on organic semiconductors are the basic devices in the field of organic electronics and flexible electronics,which can be used in numerous applications,including flexible flat panel display and logic circuits,organic storage devices and sensors,etc.However,the irregular arrangement of organic molecules and the film patterning have greatly limited the development and application of organic field-effect transistors.In this thesis,we report a novel method to construct organic microwires using a microfluidic template,which enables the fabricated semiconductors with well-defined sizes,as well as precise control of their location and alignment in devices assembly.Furthermore,we employ these semiconductor microwires to construct different types of devices like organic microwires transistors and organic/perovskites microwires heterojunction transistors,and to study the electrical and photoelectric performance of these devices.Details are as follows:(1)Organic microwires transistors are prepared using the microfluidic template method.First,the ordered organic microwires are fabricated by the microfluidic template method,and then p-type and n-type organic microwires transistors are constructed.The performances of microwires and thin-film transistors are compared.High-performance p-type and n-type organic microwires transistors are obtained,the corresponding carrier mobilities can reach 0.28 cm²·V^-1·s^-1 and 0.05 cm²·V^-1·s^-1,respectively.(2)In order to confirm the universal applicability of the above method,we adopt the microfluidic template method to fabricate perovskite microwires and characterize the corresponding photodetector performance.The photodetectors with a responsivity of 0.2 A·W^-1 and a response time of less than 50 ms are obtained.(3)On the basis of the above work,we present the fabrication and characterization of transistors and phototransistors composed of organic/perovskite microwire heterojunctions.The heterojunction transistors combine the advantages of both organic semiconductor and perovskite,which have strong responses to both light and gate modulation,and exhibit responsivity of 350 A·W^-1.These works described above will be helpful for the manufacture and application of microwire-based devices,and pave the way for the subsequent construction of optoelectronic devices with complex structure.