SEMICONDUCTOR DEVICE FOR ELECTRON EMISSION IN VACUO

摘要

The invention relates to a semiconductor device for electron emission in vacuo, comprising a stack of a first semiconductor layer of type n (9), a second semiconductor layer of type p (7), which forms a first semiconductor junction (J1) with the first layer and a third semiconductor layer of type n (8), which forms a second semiconductor junction (J12) with the second layer and a surface region (10) of which faces the vacuum. The first junction (J1) is directly polarised to form an electron injector. The second junction (J2) has inverse polarisation to form an electron emitter in vacuo. The semiconductor material of the second layer to the input layer inclusive has a forbidden bandwidth Eg meeting the following inequality: Eg> chi /2 where chi is the electronic affinity of the material. A fourth semiconductor layer (11) which is non-intentionally doped (nid) is preferably sandwiched between the second and the third layers and a fifth semiconductor layer (9) is sandwiched between the layer (6) and the layer (7), with a doping weaker than the layers (6, 7 and 8). The above is of application to electronic and optoelectronic devices using an electron source.