We have investigated the dependence of polycrystalline pentacene thin-film transistors (TFTs) characteristics on work function of source-drain contact metals. The pentacene TFTs using Mg, Al, Ag, and Au source-drain electrodes showed only p-type characteristics and the field-effect hole mobilities were strongly dependent on their work function. On the other hand, the pentacene TFTs using Ca source-drain electrodes showed typical ambipolar characteristics. The field-effect hole mobility of 4.5 × 10 -4 cm 2 /Vs and field-effect electron mobility of 2.7 × 10 -5 cm 2 /Vs were estimated from saturation currents. Appearance of an electron enhancement mode in pentacene TFTs was ascribed to the lowering of barrier for electron injection at source electrodes.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics