Device for the multiplication of charge carriers by an avalanche phenomenon and application of the said device to photosensors, photocathodes and infrared viewing devices

A device for the multiplication of charge carriers of a given type by means of an avalanche phenomenon, said device comprising:

• a first electrically semi-conductive material, said material being a single semiconductor of homogeneous composition;
• substantially planar parallel layers provided in said material, said layers having a first conductivity type depending on the type of said charge carriers, said layers being separated by portions of said material, the thicknesses of said layers being far smaller than the thicknesses of said portions, said layers introducing potential wells in a direction substantially perpendicular to said layers, said wells forming reservoirs in which said charge carriers are confined, said portions have a second conductivity type, the number of doping impurities of said layers being greater than the number of doping impurities of said portions;
• means for applying a working electric field substantially parallel to said direction;
• at least one of said charge carrier being injected in said device, being accelerated by said working field and being capable of producing, through a process of impact ionization, the ejection of a charge carrier of said type out of one of said potential wells, said charge carriers being guided by said working field, said ejection process being repeated from said potential well to the next and thus constituting said avalanche phenomenon.