Electron emission behaviors of polycrystalline-diamond-coated silicon emitters

In this work the electron emission characteristics of the polycrystalline-diamond-coated silicon field emission array (DSFEA) are examined, and its emission behavior is compared with that of the bare Si field emission array (SFEA). For the DSFEA, a linear ohmic and a Fowler-Nordheim (FN) emission are observed in the low- and high-applied-voltage regions, respectively. The threshold voltage for DSFEA is 235 V. The maximum emission current of 0.23 mA is obtained at an applied voltage of 500 V. Using the FN plot, the effective work function of DSFEA is calculated to be 0.2115 eV. The emission properly of DSFEA in threshold voltage lowering is attributed to the structural defects in the diamond film, i.e., graphite inclusions, grain boundaries and surface protrusions of the diamond film.