Transistor device, a memory device and a method for operating a memory device

A field-effect transistor (FET) device comprising:

• a semiconductor layer of a wide-bandgap semiconductor, the semiconductor layer comprising a source region, a drain region, and a floating body region between the source region and the drain region;
• a first gate and a second gate arranged along the floating body region of the semiconductor layer, wherein the first gate is arranged at a first side of the semiconductor layer and the second gate is arranged at a second side of the semiconductor layer opposite the first side;
• and
• a charge storage island arranged along the floating body region in contact with the second side of the semiconductor layer such that the charge storage island is arranged between the floating body region and the second gate, wherein the charge storage island is configured to define a potential well for charge carriers attracted from a channel induced in the floating body region when the FET device is in an on-state.