Space-charge electrets as gate dielectrics in organic electronic devices

The basic element in organic electronics is the organic field effect transistor, consisting of an organic semiconductor and a gate dielectric. Whereas organic semiconductors are widely investigated, much less attention is paid for the search on organic gate dielectrics. Space-charge and dipole electrets offer a huge potential as gate dielectrics in organic field effect transistors. An example is the development of a nonvolatile organic field effect transistor memory based on fullerenes as molecular semiconductor and polyvinylalcohol as space-charge electret. In polyvinylalcohol, most probably mobile ions are the charge carriers that are trapped with long retention times. The memory element is characterized by a large metastable hysteresis in the transfer characteristics, the drain source current versus gate voltage. Improvements and even further going applications are possible by the use of better space-charge electrets.