基本信息
摘要：770,066. Semi-conductor devices. SIEMENSSCHUCKERTWERKE AKT.-GES. Oct. 20, 1954 [Oct. 20, 1953; April 24, 1954], No. 30283/54. Addition to 750,134. Drawings to Specification. Class 37. [Also in Group XL (b)] A semi-conductor device according to the parent Specification has a surface of the semiconductor subjected to radiation which provides a third means for controlling the currentvoltage characteristic of the device. The device, as described in the prior Specification, comprises an intrinsic semi-conductor body subjected to electric and magnetic fields at right angles to each other, thereby modifying the resistance of the semi-conductor body due to the production of a depleted region (the magnetic barrier layer) having fewer electrons and holes than exist under thermal equilibrium conditions. The depleted region may be 10 cms. in thickness. In the present invention, radiation is applied to the depleted side of the body to generate electron-hole pairs therein which reduces the extent and intensity of the depleted region, and thus modifies the semi-conductor resistance. The arrangement may be such that the radiation penetrates the whole of the magnetic barrier layer, thus effectively reducing its thickness, or only the surface region, thus weakening the effect of the barrier layer by increasing the number of carriers in this region. The radiation may consist of light, infra-red, X-rays, γ-rays, or particles such as neutrons or α or #-rays. Details of the depth of penetration for varying wavelengths, are given for germanium and indium antimonide. Silicon, germanium, grey tin, FeS, and A III B V compounds such as InSb, GaSb, AlSb and InAs, are given as examples of semi-conductor material. The importance of carrier mobility is discussed and the invention enables the dark current to be maintained at a low level when using relatively low resistance materials. The arrangement is less sensitive to temperature than PN-junction arrangements. The device may be used as a rectifier, as described in the parent Specification, by causing two opposite surfaces of the semiconductor body to have different carrier recombination characteristics, and the radiation may then be used to control the rectification characteristic. By connecting such a device in series with an A.C. source and a D.C. motor (Fig. 8 not shown), the speed of the motor may be controlled according to the intensity of the radiation. The device may also be used as a photo-electric cell, and also for demodulating a modulated radiation to provide an electrical output (Fig. 11, not shown).
摘要附图：
