Ultrathin and highly flexible parylene-C packaged carbon nanotube field effect transistors.

摘要

Flexible electronics are promising alternatives to traditional silicon based electronics for applications that require characteristics such as lightweight, ease of fabrication, mechanical flexibility, low cost production, and able to be wrapped into complex shapes. The advances in organic materials and related processing techniques have enabled several emerging applications for flexible electronics such as electronic paper, wearable displays, large area antennas, RFID tags, etc. Despite the growing momentum in this field, the low field effect mobility of the organic molecules used in realizing these devices has limited their performance (eg. mobility of pentacene based transistor is ∼1 cm2/Vs). Carbon nanotubes with their unique chemical, physical and mechanical properties are promising active materials for high performance electronic devices. The ability to deposit and pattern CNTs from solution phase over a large area presents them as ideal candidates for flexible electronics.;The goal of this thesis is to realize ultrathin, highly flexible and biocompatible electronic devices using solution processed SWNTs on flexible parylene-C substrates. Due to its excellent dielectric and passivation properties, parylene is also used as an encapsulation layer. The adhesion and gate dielectric properties of parylene-C for CNT based flexible devices are evaluated. Next, parylene-C packaged SWNTs based thin (12im) film transistor is designed and fabricated, electrical characteristic before and after encapsulation is evaluated, and then its mechanical flexibility is studied. The stability of all-parylene CNTFETs are also investigated in 0.9% sterile solution of sodium chloride for 42 days. Finally, a room temperature integration of SWNTs into three dimensional architectures is demonstrated for the realization of high density flexible devices.