A storage device includes a first semiconducting layer having a p-dopant
and a second semiconducting layer having an n-dopant, disposed on the
first semiconducting layer forming a junction between the first and the
second semiconducting layers. The storage device also includes a charge
trapping structure disposed on the second semiconducting layer and a
conductive gate, wherein the conductive gate and the charge trapping
structure move relative to the other, wherein an electric field applied
across the second semiconducting layer and the conductive gate traps
charge in the charge trapping structure.