Abstract: An electron emitting device including an active semiconductor layer having a surface from which electrons are emitted. The layer is doped with impurity atoms at a density which decreases with distance from the surface.

Abstract: In manufacturing a semiconductor device by epitaxial growth from the liquid phase on a substrate of layers of gallium arsenide or gallium aluminum arsenide doped with elements such as germanium, the last growth melt is wiped off and the structure is cooled to a temperature from room temperature to 200.degree. C. During cooling, the structure's upper surface is contacted with a liquid gallium melt in such a manner that the doping elements present in the few remaining drops of the last growth melt not removed by the wiping off are dissolved.

Abstract: A microchannel plate for secondary electron emission intensification, having channel walls which are rounded so as to increase the interception of secondary electrons formed due to the incidence of primary electrons on the ends of the said channel walls.According to the invention, the method of manufacturing such a channel plate consists of softening the channel wall material and by bombardment of the glass of the input surface by means of an energy-carrying beam of high power for a very short period of time. The glass of the walls at the input surface side then assumes a rounded shape under the influence of gravity and the surface stress of the glass.