Beitrag zur Klärung des Grossen Flusswiderstandes von Selengleichrichtern

The differential resistance of selenium rectifiers in the linear part of the V–I characteristic in the forward direction is considered; its value is three orders of magnitude higher than that of monocrystalline Ge-or Si-rectifiers and is closely connected with the current carrying capacity of selenium rectifiers. X-ray pictures showing the crystalline structure of selenium layers after heat treatment of different duration show increasing crystal growth in the polycrystalline selenium layer so that the differential resistance should be reduced. Measurement of the differential resistance, however, showed a gradual increase following an initial decrease, which is obviously connected with the process of ageing.