A new gradually graded p-i-n structure produced by electron irradiation in germanium (III) magnetoresistance

A gradually graded p–i–n structure is produced near the surface in an n-type germanium slice by irradiating it with high energy electrons. In this structure negative magnetoresistance appears in the dark at a temperature below 160 K, when a magnetic field is applied in such a direction that paths of carriers are deflected away from the surface exposed to the electron beam. However, when the sample is illuminated by light from a tungsten lamp, it disappears and becomes positive magnetoresistance. The observed negative magnetoresistance can be interpreted in terms of the change in the recombination of carriers injected from the junction and contact, because the ratio of the number of carriers lost by recombination to the total number of injected carriers is dependent on their paths which are deflected by the magnetic field.