A method of operating a device comprising: a first conductor layer defining a plurality of source conductors each associated with a respective group of transistors, and a plurality of drain conductors each associated with a respective transistor; a semiconductor layer defining semiconductor channels between said source and drain conductors; a second conductor layer defining a plurality of gate conductors each associated with a respective set of transistors, and one or more storage capacitor conductors capacitively coupled to the drain conductors for a respective set of transistors; the method comprising: using the gate conductors to switch the transistors between on and off states; and using the storage capacitor conductors to reduce the conductivity of one or more semiconductor layer connecting the drain conductor of each transistor in the on state to source and/or drain conductors other than those associated with that transistor.