1. An ambipolar synaptic device comprising: a semiconductor layer; a gate operatively associated with the semiconductor layer; a first structure configured for injecting both electrons and holes into the semiconductor layer, and a second structure configured for trapping, de-trapping and/or recombination of both electrons and holes injected by the first structure into the semiconductor layer; wherein the first structure includes a source/drain structure comprised of a highly doped region of a first doping type confined within a highly doped region of a second doping type, the second structure includes a channel having the first doping type operatively associated with the source/drain structure, and further including a gate dielectric or barrier layer between the gate and the channel, at least one of the channel and gate dielectric or barrier layer including quantum wells or quantum dots.