| 摘要 |
<p>In one example of construction, a high-performance photocathode has the following structure: a transparent layer formed of P+ type semiconductor material having a forbidden band of sufficient width to ensure that this layer is transparent to the photons of the light to be detected; an absorption layer constituted by ten first sublayers formed of P+ type semiconductor material with a forbidden band of sufficiently small width to have two-dimensional electronic properties in order to achieve efficient conversion of the photons into electron-hole pairs and by ten second sublayers interposed between the first and formed of the same material as the transparent layer, the second sublayers being sufficiently thin to permit passage of electrons by tunnel effect and the thickness of the first sublayers being sufficient to permit absorption of the photons of all wavelengths of the light to be detected; a transport layer formed of the same material as the first sublayers; a layer of Cs+O for reducing the energy-gap potential so as to permit emission of electrons into vacuum.</p> |
