Calder’ On Technique Based Integral Equation Methods In Computational Electromagnetics

Although a considerable progress has been made of the study of organic thin film transistor（OTFT）, there are still many factors that limit the application of organic thin film transistor. At current stage, many organic thin film transistors require very high operating voltage, high voltage power not only have a great waste of energy, but also greatly limits the application field of organic thin film transistor. By reducing the thickness of the insulating layer, or using high relative permittivity dielectric layer material can obtain an insulating layer with a high capacitance. This paper studies the impact of a high dielectric constant material ZrO₂ organic thin film transistor performance.The main work of this paper is the following aspects:To achieve low-voltage driving TFT device, at first we should analysis the performance of OTFT device based on different annealing temperatures prepared solution method ZrO₂ dielectric layer, the annealing temperature was 200℃, 250℃, 300℃ and 350℃. Through films I-V, C-F and related electrical parameter analysis, experimental results show that when the annealing temperature of insulating layer was 350℃ high, the OTFT device shows the best performance. When the annealing temperature was 350℃, the carrier mobility was increased 6 times, reach 0.231 cm2 /V · s, the threshold voltage of the device is-0.25 V, improved 61%. The results show that the device performance is mainly due to the annealing temperature of the insulating layer, so that the inorganic insulating material is converted from Zr Cl4 to ZrO₂ more completely, and the surface roughness was reduced. Pentacene layer grow on the surface of insulating film shows better quality, the interface charge trap on the insulating / semiconductor layer have a density decrease, so that the device achieve optimal performance.Different properties of the OTFT device with different ZrO₂ dielectric layer thickness were studied. The thickness of ZrO₂ dielectric is controlled by changing the second layer concentration of Zr Cl4 solution. According to the optimum annealing temperature of the previous chapter, annealing temperature of 300℃ is chosen. The insulating layer has a thickness of 58 nm,82nm, 107 nm and 135 nm was measured respectively.The film performs analysised by C-F and related electrical parameter, experimental results show that when the insulating layer thickness is 58 nm, devices has the best performance. When the insulating layer thickness is 58 nm, the carrier mobility is 0.169 cm2/V·s, improved 81.7%, the threshold voltage of the device is-0.1V. Through the relevant parameters analysis, the device performance change is mainly due to reduced thickness of the insulating layer film, thus the device capacitance increased per unit area, the device at the same gate voltage attract more carriers cumulative in the active layer and the insulating interface, so that the electron density of the channel is increased, thereby increasing the output saturation current of the device, enhancing the field effect device to improve device performance.