High work function materials for source/drain contacts in printed polymer thin film transistors
Studies of materials for source-drain electrodes in inkjet printed polymer based thin film transistors (TFTs) are reported. The first system is a blend of Ag nanoparticles with Pedot:PSS and the second is an ethylene glycol-doped Pedot:PSS solution, here referred to as modified-Pedot. The semiconductor used is the polythiophene derivative poly [5,5'-bis(3-dodecyl-2-thienyl)-2,2'-bithiophene] (PQT-12). Pedot:Ag blends and modified-Pedot yield TFTs with mobilites of the order of 10-2 cm2/Vs and 10-3 cm2/Vs respectively, subthreshold slopes of around 1.6 V/decade and ION/IOFF ratios of the order of 106-107. Both systems show considerable improvement with respect to printed TFTs using Ag nanoparticles as source-drain electrodes. Results on the resistivity and morphology of the films are discussed along with device characteristics analysis.
Sholin, V. ; Street, R. A. ; Carter, S. A.; Arias, A. C. High work function materials for source/drain contacts in printed polymer thin film transistors. Applied Physics Letters. 2008 February 11; 92: 063307.