Detection of optical and infrared radiation with DC-biased electron-tunneling metal-barrier-metal diodes

The voltage obtained from metal-barrier-metal (MBM) diodes by phase-sensitive detection when illuminated with optical and near-infrared radiation, modulated at 880 Hz, has been studied as a function of an applied dc bias. The detected voltage is a nonlinear function of the bias voltage for high junction impedances, and linear for low junction impedances. The nonlinearity in the junction has been shown to be consistent with electron tunneling theory.