Effect of using split-gate electrodes on a pentacene based field effect transistor

We present our results of using split-gate electrodes on an evaporated film of pentacene in a field effect transistor configuration. Pentacene was purchased from Aldrich and used as received. Two split-gate electrodes, each 20 $\mu $m wide and separated by 4 $\mu $m were patterned on a Si/SiO$_{2}$ substrate over which an additional 100 nm of SiO$_{2}$ was grown. Source (S) and drain (D) electrodes were evaporated onto the substrate, centered on the buried split-gate structure. Finally, a pentacene film of thickness 500 nm was evaporated onto the patterned substrate in vacuum (2x10$^{-5}$ mbar). Current voltage characteristics of this device show negligible S/D drain current under S/D biases up to -10V with either or both gates turned ``off'' (gate electrodes grounded) but does show an increase of about two orders of magnitude in the S/D current (at a S/D bias of -10V) when both gates are turned ``on'' with a voltage of -12 V. Several devices were tested and gave similar results. Based on these results the device can be treated as two gate controlled switches placed in series and is analogous to a logic AND gate.