A SEMICONDUCTOR DEVICE

摘要

In a semiconductor device comprising a first semiconductor layer (4) doped by dopants assuming such deep energy levels in the semiconductor material of said layer that the majority thereof will not be thermally activated at working temperature a contact layer (11) is of a metal having a work function (ζ) being for a n-type doping substantially as high as or higher than the electron affinity (ψ) of the semiconductor material and for a p-type doping substantially as high as or lower than the sum of on one hand the band gap between the conduction band and the valence band and on the other the electron affinity of said semiconductor material. The device comprises an irradiation source adapted to emit radiation of an energy being high enough for activating said dopants and thereby controlling the barrier against charge transport between the contact layer and the semiconductor layer.