Development of Nanoparticle-Based High Current Density Cathode for THz Devices Application

Scandia (Sc 2 O 3 )-doped tungsten nanoparticle-based high current density cathode is developed for the application in terahertz (THz) devices. This paper involves synthesis of scandia-doped tungsten nanoparticle powder using chemical technique, estimation of optimum porosity, and development of pellet with required porosity by optimizing process parameters. The cathode, made out of the above pellet, is tested in an analytical system containing Auger electron spectroscope and anode. The results show that the cathode can deliver more than 100 A/cm 2 current density with stable emission—strongly recommending it as a candidate for the use in a THz device. Theoretical estimates show that the void porosity is to be kept at 21% for proper surface coverage to produce good emission with long life.