An analytic model for the polymer grid triode

The polymer grid triode (PGT) is a novel semiconductor device constructed using a self-assembling porous conducting polyaniline (PANI) network placed between two semiconducting polymer layers, and sandwiched between metal electrodes. The structure behaves as a three-terminal device capable of current amplification, with the PANI network functioning as the control grid. An analysis of the generalized field-assisted carrier injection by tunneling, controlled by the grid voltage, is presented to model the charge injection and transport in the PGT. The results are in good agreement with the measured current-voltage characteristics. Further, an effective diode model for the PGT is introduced, and a simple, intuitive expression for charge transport in the presence of the grid network is obtained. In the effective diode regime, the current through the PGT is a function of (V-ac-PVag); i.e., I(ac)approximate to I(V-ac-PVag) where P is a geometric factor, as required for use in image processing applications. Other application possibilities for the PGT are surveyed, and the limitations of this device when placed in common circuit configurations are discussed. (C) 1996 American Institute of Physics.