CMOS-compatible metal-semiconductor-metal photodetector

The present invention relates to photodetectors, and in particular to Metal-Semiconductor-Metal (MSM) photodetectors. A novel photodetector CMOS-compatible photodetector is disclosed in which photo-generation of carriers (electrons) is carried out in the metal of the electrodes, rather than as electron-hole pairs in the semiconductor on which the metal electrodes are deposited. The novel photo detector comprises a silicon or other semiconductor substrate material characterized by an electron energy bandgap, and a pair of metal electrodes disposed upon a surface of the silicon to define therebetween a border area of the surface. One of the two electrodes being exposed to the incident radiation and covering an area of said surface which is larger than the aforesaid border area, the aforesaid metal of the electrodes being characterized by a Fermi level which is within said electron energy bandgap.