The authors fabricated organic Schottky diode using ink-jet print, where 6,13-bis(triisopropyl-silylethynyl) pentacene (TIPS-pentacene) was used as an active layer. As for a reference diode, they also fabricated pentacene Schottky diodes on the polyethersulfone substrate by evaporating pentacene as an active layer. Alternatively, the Ohmic contact variations due to the presence of either self-assembled monolayer or Poly(3,4-ethylenedioxythiophene):polystyrene-sulfonate acid (PEDOT:PSS) layer was also investigated using the evaporated pentacene Schottky diode. They found that pentacene Schottky diode with PEDOT:PSS layer yielded the best rectifying behavior in terms of the contact voltage, forward bias current, and rectifying ratio. In this study, Au was used to form Ohmic contact, while Al was used to form Schottky contact with either pentacene or TIPS-pentacene. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3328803]