Abstract: A device for the multiplication of charge carriers of a given type by an avalanche phenomenon includes:a semiconductor material of homogeneous composition, placed in an electrical field.Perpendicular to the working field, plane and parallel layers which are thin as compared with the thickness of the material separating them, are made in this material and are n-doped or p-doped depending on the type of charge carrier, the said layers forming reservoirs where charge carriers of the said type are confined. The injection of at least one charge carrier of the said type in the charge carrier multiplying device sets off the multiplication of charge carriers through a process of impact ionization. This charge carrier is accelerated by the working field and thus acquires energy sufficient to make it capable of ejecting a charge carrier of the said type from the doped layer. The charge carriers obtained are guided by the working field.

Abstract: An avalanche photodetector of the heterojunction type comprises an intermediate region between two end regions made from distinct semiconductor materials. The intermediate region comprises a lattice of slices of varying thicknesses of alternating layers of the material of the end regions thus forming a system of coupled quantum wells whose thicknesses and whose number of slices are determined so that the response time of the photodetector is less than a maximum given time, while maintaining the number of coupled quantum wells to a minimum.