Semiconductor element in which negative resistance characteristics are produced throughout the bulk of said element

998,494. Semi-conductor devices. INTERNATIONAL BUSINESS MACHINES COR. PORATION. Jan. 8, 1964 [Jan. 10, 1963], No. 797/64. Heading H1K. A biasing electric field E is applied along a first axis of a semi-conductor crystal 5 having symmetrical axes and symmetrical multi-valley conduction bands producing negative resistance characteristics along a second axis (differing from the first axis) along which a second electric field is applied. The effect may be enhanced by the application of mechanical stress along one axis. The semi-conductor material has an energy band structure for its majority carrier consisting of several valleys whose constant energy surfaces are ellipses (preferably of large eccentricity) and is capable of producing hot electrons such that, when power is applied to the crystal by means of an electric field, the product of the mobility and intervalley relaxation time of the hot electrons decreases as the power applied by the electric field increases. N-type germanium and silicon, Bi 2 Se 3 , Bi 2 Te 3 , and semi-conducting alloys of bismuth and antimony are stated to be suitable materials.