A semiconductor device, such as a memory device or radiation detector, is disclosed, in which data storage cells are formed on a substrate 13. Each of the data storage cells includes a field effect transistor having a source 18, drain 22 and gate 28, and a body arranged between the source and drain for storing electrical charge generated in the body. The magnitude of the net electrical charge in the body 22 can be adjusted by input signals applied to the transistor, and the adjustment of the net electrical charge by the input signals can be at least partially cancelled by applying electrical voltage signals between the gate 28 and the drain 22 and between the source 18 and the drain 22.