Flexible and transparent carbon nanotube (CNT) devices have great potential for next generation displays and electronic devices. However, fabrication of CNT electronic devices on transparent and flexible substrates is more challenging than on the conventional solid substrates such as silicon.
Fabrication of CNT electronic devices on nonconventional substrates will enable the utilization of many desired properties of the substrates, such as flexibility, transparency, and low-cost with such applications as flexible displays, paper electronics, solar cells, sensors, and bio-integrated electronics. In traditional approaches, devices are directly fabricated on the desired substrates, so the choice of substrates is limited by their compatibilities with fabrication processes such as temperature, chemicals, and handling requirements.
In this dissertation, I will present a novel and simple Poly-methyl methacrylate (PMMA)-supported transfer printing technique. This method is based on a simple contact printing process that enables direct transfer and positioning of CNT electronic devices fabricated on the initial substrates to receiver substrates.
I, first, fabricated the CNT devices on Si substrates with a SiO2 layer with conventional semiconductor processes. Then, the whole CNT devices were released from the substrate on spin-coated and cured PMMA film with SiO2 as a sacrificial layer.
We confirmed that the CNT devices transferred to PMMA film mostly maintains the original IV characteristics. This method also enables to bring the CNT devices onto various nonconventional substrates such as papers, fabrics, plastics, metal foils, metallic cylinder, glasses, and polymers that have been not easily accessible previously. Devices characteristics on the nonconventional substrates will be discussed and compared with those on Si/SiO2 substrates.