Circuit techniques for organic and amorphous semiconductor based field effect transistors

Field effect transistors (FETs) built with noncrystalline semiconductors, such as amorphous hydrogenated silicon (a-Si:H) and organic thin film transistors(TFTs) are of immense interest in the development of large area sensor and display systems [1]-[3]. However, these FETs have a time variant threshold voltage due to bulk and interfacial charge trapping, and hence, to-date these devices have been mostly used as switches. This paper identifies circuit techniques to enable time invariant transfer characteristics using these devices, thereby enabling versatile analog design.