表面修饰制备高性能薄膜晶体管

Preparation of High-Performance Organic Thin-Film Transistor Through Surface Modification

应用聚苯乙烯/氯硅烷复合材料作为栅绝缘层的界面修饰层制备了高性能的并五苯场效应晶体管。原子力显微镜观察发现,界面修饰对并五苯半导体薄膜的生长形貌产生了很大影响。在空白二氧化硅上沉积的并五苯晶粒尺寸都小于150nm,而在修饰过后二氧化硅的表面生长的并五苯晶粒尺寸多在200～400nm。大的晶粒尺寸能够减小晶粒间的界面,从而有效提高电学性能。表面改性的并五苯场效应晶体管的关态电流约为10-10 A,电流的开关比超过106,最大场效应迁移率约可达1.23cm2.V-1·s-1,而未处理的晶体管的场效应迁移率仅有0.011 8cm2.V-1·s-1。

High-performance pentacene organic thin film Transistor （OTFT） with interface modification layer of polystyrene/chlorosiiane composite material was developed. The AFM images show that the growth morphology of pentacene semiconductor film was affected by interface modification. The pentacene grains grown on modified SiO2 substrates with dimen- sions in the range of 200-400 nm are larger than those grown on bare SiO2 substrates which have sizes less than 150 nm. Large particle size can reduce intergranular interface so as to im- prove the electrical performance. The output and transfer curve, on/off current ratio, threshold voltage and field-effect mobility of the device were obtained by electric measure- ments. The transfer curve showed an on/off current ratio exceeding 106 with the off-current of about 10 10 A. The device with interface modification has a maximum field-effect mobilityof up to 1.23 cm2 · V-1 · s-1 , compared to the 0. 0118 cm2· V-1 · s -1 of OTFT on bare Si（）~ substrate.