A photon receptor having a sensitivity threshold of a single photon is readily fabricated on a nanometric scale for compact and/or large-scale array devices. The fundamental receptor element is a quantum dot of a direct semiconductor, as for example in a semiconductor (such as GaAs) isolated from a parallel or adjacent gate electrodes by Nano-scale gap(s). Source and drain electrodes are separated from the photoelectric material by a smaller gap such that photoelectrons created when a photon impinges on the photoelectric material it will release a single electron under a bias (applied between the source and drain to the drain) to the drain electrode, rather than directly to the gate electrode. The drain electrode is connected to the gate electrode by a detection circuit configured to count each photoelectron that flows to the gate electrode.