Source-gated thin-film transistors

The on-current of a source-gated transistor is determined by the current passing through a reverse biased source barrier. Since this current is field-dependent, it can be controlled using a gate located directly opposite the source barrier. This concept leads to major changes in thin-film transistor behaviour compared with the standard FET. In particular saturation voltages, short channel effects and excess carrier concentrations are reduced while internal electric fields are enhanced. These features lead to lower power dissipation and higher output impedance compared with a FET as well as improvements in stability and speed. The SGT is particularly useful for high-performance circuits in poor-quality semiconductors.