Photocathode and electron tube

摘要

This photocathode comprises: InP substrate 1; InAsx2P1-x2(0<x2<1) buffer layer 2; Inx1Ga1-x1As (1>x1>0.53) light-absorbing layer 3; InAsx3P1-x3 (0<x3<1) electron-emitting layer 4; InAsx3P1-x3 contact layer 5 formed on the electron-emitting layer 4; active layer 8 of an alkali metal or its oxide or fluoride formed on the exposed surface of electron-emitting layer 4; and electrodes 6 and 7.