Preparation Of Organic Thin-film Transistors Using Inkjet Printing Technology

The pressures of the competition make the electronic industry have to reduce the cost. The OTFT has gained significant interesting by the improving organic semiconductors'industry. We can see inkjet printing machine everywhere, and they can print many different materials, from the polymer materials to the metal materials. Inkjet printing has been recognized as the key technology to make the polymer deposited. It's simple, fast and easy patterned. Inkjet printing needn't contact, pressure and plate. It input the information which stored in the computer to the inkjet machine. So it has very important significant to study how to printing OTFT using inkjet printing technology.The task we have done is the national natural science foundation-funded projects (60776056). We adopt with the experimental and theoretical analysis, software simulation to finish some experimental objectives.This paper analyzes the OTFT's research and development status between domestic and foreign countries. We studied the structure of the OTFT, and compared its preparation process and the film-forming technology. We analyze the technical characteristics of inkjet printing in modern times. We discussed the character between the DOD inkjet and the CIJ. We choose the piezoelectricity inkjet to work on our experiments. We also discussed the physical properties of the ink.We know the physical properties of the experiments'machines by printing the original ink. We could know the resolution of the experimental equipment by the compared printed lines. We printed the PEDOT/PSS, and test the resistance under the different width, length and temperature of the lines. It reflects the performance of the device electrode materials.This paper uses the mathematical methods to establish several models. The dynamics in the piezoelectricity print head, the viscosity of the polymer ink, the droplet's velocity on the jet times and the process of the droplet getting down were simulated. From the simulation, we know the relationship between the viscosity and the velocity, the movement viscosity and the emission volume, the jet velocity, density and the radius of the print head, and et al. Relying on the relationships, we could control and adjust the hardware performance of the inkjet printing. For better droplet patterned, we also can adjust the viscosity and the velocity.In this paper we use Gambit and Fluent to simulate different types of the print head. The pressure distribution, velocity distribution and so on inside the print head were shown under a certain pressure conditions. Water and PEDOT/PSS were used as materials to simulate the jet velocity. We find that frustum is the best print heads'shapes. We have gained a lot of data about the parameters from the simulation. These will help us transform the print head. As long as the appropriate pressure settings and the flow rate changed, the droplet will be better patterned. This will guide our following tasks.