Study On Physical Properties Of Stretchable Insulating Materials And Construction Of Fully Stretchable Organic Field Effect Transistors

To meet people's constantly increasing demand for portable and comfortable electronic products,the fields of electronic skin and stretchable electronic devices are developing rapidly.The semiconductor materials and conductor materials for the fabrication of basic electronic devices are generally rigid,which are easy to break and unable to be elongated.Polymer insulating elastomers are the key material to help the majority of rigid semiconductors and conductors realize stretchablity.They also have good insulating properties,so in stretchable electronic devices,polymer insulating elastomers play a key role in including substrate,electrode,active layer,insulating layer,almost all parts.Unfortunately,there is still a lack of systematic reports on detailed information about insulating elastomers in stretchable electronic devices.Therefore,my work has systematically studied and characterized the mechanical properties,surface properties and dielectric properties of five widely used low-cost commercial insulating elastomers,which are vital properties affecting the performance of stretchable devices.And by comparing the performance parameters of insulating elastomers,Sylgard-186 is preferably used as the insulating layer of the intrinsically stretchable organic field effect transistor.The Sylgard-186 insulating layer can provide high elongation at break,low surface energy,and suitable dielectric constant,capacitance with excellent frequency stability,and low leakage current density,and then relying on the excellent properties of Sylgard-186 insulating layer to fabricate high-performance intrinsically stretchable transistors,the main research contents are as follows:1.After systematic investigation,five kinds of widely used commercial polymer insulating elastomers are selected.They are easy to obtain,low in price,able to be made to a large-area film by solution method,transparent in texture,adhesive on the surface,and have excellent mechanical properties and certain dielectric properties,which are suitable for the research needs of this work.The transparency,surface adhesion,surface energy,Young's modulus,elongation at break and other properties of the five selected materials were characterized in detail and comprehensively.2.The electrical properties of five materials as insulating layer materials are further investigated systematically.The sandwich structure device of“gold film-insulating layer-silicon”was prepared,and the capacitance-frequency dependence,dielectric constant and leakage current of each material were characterized.In order to show more clearly that each material acts as insulating layers in OFETs.Then prepared five kinds of DNTT organic field effect transistors with different insulating layers.Statistics and characterization of the device performance are carried out,and the comparison of various parameters is selected.Sylgard-186 is the most suitable material as the insulating layer of stretchable organic field effect transistors.3.Using Sylgard-186 as the insulating layer material,combined with photolithography and based on the idea of separated fabrication and lamination process,an intrinsically stretchable OFET with high was successfully prepared by the all-solution-processed method,and the mechanical and electrical properties were tested.The electrical properties of intrinsically stretchable transistors are fully characterized,and the results show that Sylgard-186 intrinsically stretchable organic field-effect transistors have superior performance,with a mobility as high as 1.81 cm²V^-1s^-1,and stable mobility of 1.4 cm² V^-1s^-1 when subjected to 60%strain and 0.96cm² V^-1s^-1at 100%strain,which is one of the highest performance values of a stretchable OFET.This is the first time that Sylgard-186 has been applied to stretchable transistors.This work provides general guidance for the selection of commercial insulating elastomers in stretchable electronic products and broadens the way to manufacture high-performance stretchable OFETs.