Gate-voltage control of optically-induced charges and memory effects in polymer field-effect transistors

Memory operations in polymer phototransistors have been demonstrated. A fraction of light-induced drain current in the depletion mode of a polythiophene-based field-effect transistor persists after switching off the photoexcitation, and can be erased by reversing the gate voltage (V-g) (see Figure). Write, store, read. and erase operations can be performed by applying a combination of gate voltages and incident light over a wide temperature range.