Feasibility of tunable infrared detectors using metal-insulator-metal structures

It is suggested that metal-insulator-metal (MIM) structures under bias can be used as voltage-controlled tunable detectors. Theoretical results are based upon adapting a theory of photostimulated field emission to the MIM geometry. It is shown that tunneling resonances, which exist both below and above the tunneling-barrier maximum, provide a mechanism by which the biased MIM junction detects photons within a tunable wavelength band. It is also suggested that exploitation of these tunneling resonances can improve the sensitivity of the scanning tunneling microscope.