The inventors disclose a new high performance optical sensor, preferably of nanoscale dimensions, that functions at room temperature based on an extraordinary optoconductance (EOC) phenomenon, and preferably an inverse EOC (I-EOC) phenomenon, in a metal-semiconductor hybrid (MSH) structure having a semiconductor/metal interface. Such a design shows efficient photon sensing not exhibited by bare semiconductors. In experimentation with an exemplary embodiment, ultrahigh spatial resolution 4-point optoconductance measurements using Helium-Neon laser radiation reveal a strikingly large optoconductance property, an observed maximum measurement of 9460% EOC, for a 250 nm device. Such an exemplary EOC device also demonstrates specific detectivity higher than 5.06×1011 cm√Hz/W for 632 nm illumination and a high dynamic response of 40 dB making such sensors technologically competitive for a wide range of practical applications.