The steady-state behaviour of an extrinsic silicon IR-detector

The electrical behaviour of the Ga-doped IR detector is investigated with the aid of exact numerical solution of the one dimensional semiconductor equations. The resulting distributions of hole density, ionized impurity densities, and electric field are shown together with the detector current as a function of applied voltage, photon flux and operating temperature. These results are used to derive a simple model for small voltages which predicts the measured resistance of the detector to within 30 per cent.