Development of thin film transistors for printed inverter circuits on flexible substrates

Abstract

The development of inverter circuits represents one important research topics on organic electronics, since they are the building blocks for digital electronics. The production of flexible and printable circuits has been attracting even more attention due to its technological power on several applications, such as displays. The inverter circuits that exhibit the best performances and stability are the hybrid complementary ones (CIC-Hi), which the structure is based on the association of two thin film transistors (TFT), a p-type organic and a n-type inorganic one. The proper operation of CIC-Hi, however, is very dependent on the individual characteristics of each TFT as the charge carrier mobility µ, threshold voltage VT and operational stability. Thus, such parameters and characteristics must be carefully adjusted to produce efficient inverter circuits. The main purpose of this project is the fabrication and study of TFTs aiming the production of flexible CIC-Hi using printing techniques. We aim the fabrication of organic TFTs based on TIPs-pentacene and P3HT, and zinc oxide-based inorganic ones. Dielectrics as Al2O3 and PSQ will be used, evaluating the effect of surface treatments as their modification by self-assembled monolayers, corona discharge and O2 plasma exposure on the TFT operational characteristics. Once such characteristics are dependent on the materials' choice, treatments and fabrication techniques, the development of CIC-Hi by printing techniques becomes a major technological challenge. (AU)