US Patent 7858975 Organic field effect transistor systems and methods

An OFET includes a ferroelectric gate dielectric permitting electrical reprogramming, such as to implement an electrically re-programmable array logic (PAL) or a field-programmable gate array (FPGA). Methods of constructing such an OFET, PAL, or FPGA, can including roll printing. An OFET on a piezoelectric substrate provides local amplification in an active matrix. Methods of constructing such an OFET on a piezoelectric substrate can including rolling printing. Techniques permit direct measurement of trap distribution, such as across the channel length of an OFET device. Techniques permit direct measurement of the size and location of an electrically active grain structure in OFET devices. Techniques permit confirmation of the mechanism of operation of a number of OFET techniques, including use of silanes or thiols, or OFET operation or aging. Techniques provide an internal circuit probe, such as for a ferroelectric gate dielectric OFET or a piezoelectric substrate OFET, for example.