ABSTRACT
The electrical current density has two basic components, the conduction current and the displacement current. The conduction current density is related to the transport of carriers by the application of some driving force. This chapter outlines the analysis of transport of carriers in a material layer, focusing on the drift of carriers in a local electrical field. It starts with the formulation of the main relationships that provide the current density as a function of conductivity and electrical field. Another significant factor that determines the total electrical current is the injection of carriers at the contact, which leads us to discuss effects related to injection in organic conductors. The chapter also analyzes in detail the metal-insulator-metal model, in which the transport is driven by a constant field governed by the applied voltage. It is a simple device model, but nonetheless illustrative of many device features including contact formation properties.
