Traditionally, high-temperature manufacturing methods are employed for fabricated electronic device using inorganic semiconductors and rigid substrates . Organic semiconductors on the other hand can be processed at low temperatures and on large-area polymeric substrates. This has allowed for the development of a variety of electronic devices on flexible plastic substrates, including solar cells.Most of the organic memory transistors reported to date exploit the electric field–induced remnant polarization in ferroelectric polymer films . A considerable limitation of ferroelectric polymer memory transistors is that the coercive field required to reverse the macroscopic polarization increases with decreasing film thickness, which makes it difficult to obtain a large enough memory window with program and erase voltages below about 20 V. Also, due to the substantial surface roughness of the ferroelectric polymer films, the carrier field-effect mobility in these transistors is usually quite low.
Although silicon floating-gate transistors are excellent for high-density data storage, flexible organic floating-gate transistors are potentially useful for large-area sensors and actuators with integrated nonvolatile memory capability.
Using organic transistors with a floating gate embedded in hybrid dielectrics that comprise a 2-nanometer-thick molecular self-assembled monolayer and a 4-nanometer-thick plasma-grown metal oxide, nonvolatile memory arrays on flexible plastic substrates is realized . The small thickness of the dielectrics allows very small program and erase voltages (
6 volts) to produce a large, nonvolatile, reversible threshold-voltage shift. The transistors endure more than 1000 program and erase cycles, which is within two orders of magnitude of silicon-based floating-gate transistors widely employed in flash memory. By integrating a flexible array of organic floating-gate transistors with a pressure-sensitive rubber sheet, a sensor matrix that detects the spatial distribution of applied mechanical pressure and stores the analog sensor input as a two-dimensional image over long periods of time has been created.
Ref: Science 11 December 2009: Vol. 326. no. 5959, pp. 1516 - 1519
6 volts) to produce a large, nonvolatile, reversible threshold-voltage shift. The transistors endure more than 1000 program and erase cycles, which is within two orders of magnitude of silicon-based floating-gate transistors widely employed in flash memory. By integrating a flexible array of organic floating-gate transistors with a pressure-sensitive rubber sheet, a sensor matrix that detects the spatial distribution of applied mechanical pressure and stores the analog sensor input as a two-dimensional image over long periods of time has been created.
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