Research On The Process Of Electrohydrodynamic Printing And Directional Laser Annealing For OTFT Devices

Organic thin film transistors(OTFT)have attracted much attention in memory,sensors,and organic integrated circuits due to their advantages of low-temperature solution processing and flexible molecular structure design.The main challenge of commercial OTFT manufacturing is to improve its electrical performance and develop.large-area manufacturing method.This paper mainly studies the active layer,the key structure of OTFT devices,with the goal of improving transistor performance and large-area and high-efficiency fabrication,and has carried out research,exploration and attempts in process.Taking the poly3-hexylthiophene P3HT OTFT as the research object,the organic semiconductor P3HT fiber is prepared by the electro-jet printing process as the active layer of the OTFT device.At the same time,the laser directional annealing method is assisted to optimize the molecular orientation and crystallinity of the P3HT,improve the electrical performance of the P3HT OTFT,and realize the device High performance,mass production,and large-area manufacturing requirements.The main research contents are as follows:(1)The overall structure of P3HT OTFT is studied.Determine the structure of the transistor device and the materials of each functional layer.Silvaco TCAD was used to simulate the transistor device.The key parts affecting the device including the channel length,active layer thickness,insulating layer thickness,defect state were analyzed,and determined OTFT structure.(2)A directional laser annealing method is proposed to prepare highly ordered P3HT films.Based on the theory of heat conduction,COMSOL Multiphysics is used to analyze the thermal field model of Si O₂/Si under different laser annealing parameters(laser power,laser scanning speed),and explore its influence on the temperature distribution of P3HT thin films.According to the simulation results,the P3HT film spin-coated on the Si O₂/Si substrate was subjected to laser directed annealing,and the temperature of the P3HT film was measured by an infrared thermal imager,which verified the rationality of the simulation model.The surface microstructure of the film was characterized by XRD and SEM,and the influence of laser parameters on its crystal morphology was observed.The results show that when laser power=5W and scanning rate=0.1mm/s,the crystallinity and order of the polymer film are greatly improved,the grain size increases,and promoted carrier transport.(3)The preparation process of P3HT OTFT device based on electrohydrodynamic printing is studied.Explore the influence of printing parameters(working voltage,working distance,supply flow)on the morphology of P3HT fibers on Si O₂/Si substrates.The P3HT OTFT device array is prepared by using electrohydrodynamic printing P3HT fiber as the active layer,assisting directional laser annealing technology,magnetron sputtering Au as the source and drain electrodes,and its carrier mobility is more than 10 times that of thermal annealing devices.Achieve high-performance and mass-production of OTFT devices.