基本信息
摘要：937,456. Semi-conductor devices. GENERAL MILLS Inc. Dec. 8, 1959 [Dec 8, 1958] No. 41736/59. Class-37. [Also in Group XL (b)] A photosensor device for use in measuring light intensity comprises a grain boundary between two differently orientated single crystals. The boundary is equivalent to a series of edge dislocations which trap electrons and holes in N and P-type materials, respectively, so that the boundary attains a net negative or positive charge. If a voltage pulse of either polarity is applied between soldered contacts on the two crystals the boundary charges up to the pulse voltage and a space charge layer forms on both sides of the boundary. On removing the pulse the charge remains so that on application of a further pulse of the same magnitude only a small capacitive current pulse flows into the device which flows out again on removal of the pulse. If, prior to the second pulse, some of the charge is released from the boundary by photon bombardment the pulse restores the original boundary charge and charges up the associated capacitance. The charging current therefore is a measure of the total number of photons incident on the device between the pulses provided this is insufficient to completely discharge the boundary. Circuit arrangements for measuring the charging current and thus the light intensity are described (see Group XL (b)). Since the capacity of the device is proportional to the reciprocal of the square root of the barrier voltage the integrated light intensity may alternatively be measured continuously in terms of the charge of capacitance of the device between pulses (see also Group XL (b)). To facilitate use in such circuits as indium contact is provided to the edge of the grain boundary. Silicon is suitable for use in photosensors operated at room temperature, germanium for use at liquid nitrogen temperatures and indium antimonide at lower temperatures. The use of other A III By compounds and silicon carbide is also contemplated. A matrix 86 of 25 cells (Fig. 8) is formed from a plate 94 of semi-conductor material with a grain boundary 88 between its faces by cutting perpendicular sets 90, 92 of parallel grooves through the grain boundary from opposite sides of the plate.
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