基于喷墨打印工艺的小分子有机薄膜晶体管的制备和性能研究

发布时间：2018-04-29 23:31

本文选题：有机薄膜晶体管 + 喷墨打印　；参考：《合肥工业大学》2015年硕士论文

【摘要】：近些年,有机薄膜晶体管的发展受到了前所未有的关注。随着研究的不断深入,有机薄膜晶体管的性能已经逐渐接近传统的无机薄膜晶体管并将其应用扩展到柔性、可折叠等领域。其中利用喷墨打印技术制备有机薄膜晶体管更是由于其成本低廉、直接图案化等独特优势备受青睐。本文的主要研究方向为喷墨打印TIPS并五苯作为有源层的有机薄膜晶体管,并基于此进行了喷墨打印过程中的条件优化设置、半导体成核方式、喷墨稳定性等一系列关于喷墨打印工艺中TIPS并五苯的微观动力学行为的研究。主要内容如下：(1) 分别在UV-ozone、FDTS+UV-ozone、PVP、PETS修饰的衬底上喷墨打印TIPS并五苯单点薄膜,研究了单点薄膜尺寸大小的影响因素以及咖啡环形貌的产生原因。衬底的表面能色散分量决定了液滴干燥后的半径大小,同时降低衬底的极性分量可以有效消除咖啡环的影响。最后利用优选的PVP衬底对喷墨打印过程中的各项参数条件进一步优化,包括喷墨打印过程中的间距比设置以及溶剂选择等,通过调节打印间距比可以使器件的电流开关比达到一个最优值,考虑到溶解性等因素最终确定选用沸点高且溶解性温和的四氢化萘作为打印溶剂。(2) 分别在UV-ozone、PVP、PETS、PTS修饰的绝缘层衬底上喷墨打印TIPS并五苯制备底接触有机薄膜晶体管。实验中通过调节表面能极性控制TIPS并五苯半导体的成核方式。对于在PVP以及UV-ozone极性较高的衬底上,TIPS并五苯的成核方式为从薄膜外围向内干燥成核,从而会在沿着沟道的方向产生大量阻挡载流子传输的晶界。而TIPS并五苯在另外两种极性较低的衬底上更倾向于在整个半导体-绝缘层界面成核,这在很大程度上提高了薄膜的整体覆盖率。特别是在PETS衬底上,当膜厚达到一定程度后,器件的迁移率、亚阈值摆幅等性能参数能够得到很大幅度的提高(3) 分析影响喷墨过程中稳定性的多种因素,并基于此通过混合溶剂的方法优化了原先喷墨不稳定的四氢化萘溶剂,使其达到稳定的喷墨效果。实验中通过描绘喷墨过程中喷墨速率与频率的关系表征了喷墨稳定性,并分别利用四氢化萘以及混合溶剂制备了有机薄膜晶体管。相对于单一四氢化萘溶剂,混合溶剂在有效优化喷墨稳定性的同时还在一定程度上提高器件的性能。
[Abstract]:In recent years, the development of organic thin film transistors has received unprecedented attention. With the development of research, the performance of organic thin film transistors has been close to the traditional inorganic thin film transistors and has been extended to flexible, foldable and other fields. Among them, organic thin film transistors fabricated by inkjet printing technology are favored for their low cost and direct patterning. The main research direction of this paper is the organic thin film transistor of inkjet printing TIPS and pentabenzene as the active layer. Based on this, the optimization of the conditions in the process of inkjet printing and the nucleation of semiconductors are carried out. A series of studies on the microdynamic behavior of TIPS pentabenzene in inkjet printing process are presented in this paper. The main contents are as follows: 1) Ink-jet printing of TIPS and penta-benzene monolayers on UV-ozoneFT-FDTS / PVP modified PETS-modified substrates respectively. The factors affecting the size of the single point films and the reasons for the appearance of coffee rings are studied. The dispersion component of the surface energy of the substrate determines the radius of the droplet after drying, and reducing the polar component of the substrate can effectively eliminate the influence of the coffee ring. Finally, the optimal PVP substrate is used to further optimize the parameters in the ink jet printing process, including the setting of the distance ratio in the ink jet printing process and the selection of the solvent, etc. By adjusting the printing spacing ratio, the current-switching ratio of the device can reach an optimal value. Considering the solubility and other factors, it was determined that tetrahydronaphthalene with high boiling point and mild solubility was selected as printing solvent. The nucleation mode of TIPS pentaben semiconductor is controlled by adjusting the polarity of surface energy. The nucleation of tips and pentabenzene on substrates with high polarity of PVP and UV-ozone is dryness from the outside of the film to the inner nucleation, which will result in a large number of grain boundaries that block carrier transport along the channel direction. On the other two substrates with lower polarity, TIPS pentabenzene tends to nucleate at the interface between semiconductor and insulating layer, which greatly improves the overall coverage of the films. Especially on the PETS substrate, when the film thickness reaches a certain degree, the device mobility, sub-threshold swing and other performance parameters can be greatly improved. Based on this, the original ink-jet unstable tetralin solvent was optimized by the method of mixed solvent to achieve a stable inkjet effect. The stability of ink-jet was characterized by describing the relationship between the rate and frequency of ink-jet, and the organic thin film transistors were prepared by using naphthalene tetrachloride and mixed solvent, respectively. Compared with a single tetrahydronaphthalene solvent, the mixed solvent not only optimizes the stability of ink jet, but also improves the performance of the device to some extent.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN321.5

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