| 摘要 |
Field emission cathode.. G6A. Consists of a number of parallel wires, needles, whiskers etc. of metallic, conducting or semiconducting material. Their tip radii of curvature are less than 1 micron. The sharp tips promote field emission. In a cathode body made from a electrically anisotropic two phase semiconductor only the contacts from the second phase are formed by the very thin needles whose electrical conductivity is higher than that of the semi-conductor body. The tips project from the cathode body. The cathode body is made from InSb and the second phase forming the needles is made from NiSb. The second phase conductors is with 7 x 104 (ohm-cm)-1 higher than that of the InSb which is 102 to 103 (ohm-cm)-1. The density of the needle tips is about 106 to 107 tips per cm2. The tips are generated by etching the alloy of InSb with NiSb inclusions by an aqueous solution containing ammonium fluoride, bromine and methanol. |
