| 摘要 |
<p>PURPOSE:To contrive to make possible easily the drive of an electron beam by light by a method wherein a photoconductive film is provided on a substrate side, the light is incident in the photoconductive film and an inverse bias is applied to a p-n junction part. CONSTITUTION:An optical electron beam converting element includes a semiconductor substrate (high concentration-doped P-type Si substrate) 1 having a p-n junction 5 formed between an n-type region 4 and a p-type region and a power source which impresses an inverse bias on the p-n junction and a photoconductive layer 2 provided on the substrate are connected in series. When light L is irradiated on the photoconductive film 2, the photoconductive film 2 is brought into low-resistance state, enough inverse bias is applied to the p-n junction part 5, an electron avalanche is generated, passes through the n-type region and moreover, is accelerated by an electric field which is generated from an accelerating electrode 8 and electron beams EB are scattered and emitted. Such a material (film) 9 to decrease a work function as cesium is evaporated on the surface of the n-type region and low--energy electrons are also so contrived as to be able to be emitted.</p> |
