Invited Paper TC+EM+AS+TF+EN-ThM9
Low Temperature, High Performance Solution-Processed Metal Oxide Thin Film Transistors formed by a ‘Sol-Gel on Chip’ Process

Thursday, November 1, 2012, 10:40 am, Room 007

N-type amorphous mixed metal oxide semiconductors,such as ternary oxides , where M¹ and M² are metals such as In, Ga, Sn, Zn, have recently gained momentum because of high carrier mobility and stability and good optical transparency, but they are mostly deposited by sputtering. To date only limited routes are available for forming high-performance mixed oxide materials from solution at low process temperature < 250° C. Ionic mixed metal oxides should in principle be ideal candidates for solution processible materials because the conduction band states derived from metal s-orbitals are relatively insensitive to the presence of structural disorder and high charge carrier mobilities are achievable in amorphous structures. Here we report the formation of amorphous metal oxide semiconducting thin films via a ‘sol-gel on chip’ hydrolysis approach from soluble metal alkoxide precursors, which affords unprecedented high field-effect mobilities of 10 cm²/Vs, reproducible and stable turn-on voltages V_on » 0V and high operational stability at maximum process temperature as low as 230°C. We discuss the effect of film composition on device performance and stability.