Synthesis and characterisation of nickel nanorods for cold cathode fluorescent lamps

Self supporting nickel substrates coated with nickel nanorods having diameters distributed between 110 nm and 170 nm were electrochemically synthesised using a two-step anodisation process, using as freshly anodised nanoporous alumina membrane as template. Field emission from the nanorods was observed at a relatively low bias potential Vbias (Vbias ≤ 1 V) using scanning tunnelling microscopy; the emission current was found to be larger than that from the nickel substrate at least by a factor of 4 at Vbias = 1.0 V. Experimental results were interpreted in the modified Millikan–Lauritsen plot and values of the emission parameters were estimated using the value of the work function measured by the Kelvin probe technique. -- Highlights: ► Electrochemical synthesis of Ni nanorods, 110–170 nm in diameter on Ni substrate. ► Low bias field emission from nickel nanorods as cathodes for CCFL applications. ► Scanning Tunnelling microscopic recording of electron emissions. ► Empirical Millikan–Lauritsen law for cold field electron emission from Ni nanorods.