Semenenko M. Emission properties of silicon and carbon based nano-composite films.

The complex investigations of the effect of silicon and carbon-based nanocomposite films growth condition and modification on their electron field emission properties have been presented. The porous silicon, amorphous diamond-like carbon films and the films of the silicon oxide, with different value of the stoichiometry index have been researched. The methods of current-voltage measurement, photoluminescence and atomic-force spectroscopy have been used as main experimental techniques. A new method for the formation of the porous silicon layers by galvanic anodization to be used as field emission cathodes was analyzed. Coating porous silicon by the diamond-like carbon films leads to improvement of the electron field emission. The effect of emission enhancement of the silicon tips, coated by PE CVD and the method of the thermal vapor evaporation of the silicon powder in vacuum, were shown. The described effect was analyzed in the frame of the energetic barrier divide model. The significant growth of thefield emission efficiency out of the tips, coated by nanocomposite films, after pre-breakdown formation was revealed. This effect is caused by formation of the conductive nanochannels in the films. The physical mechanism of emission parameters improvement of the cathodes coated by diamond-like carbon and SiOx films with the formed conductive nanochannels into the films was proposed. The considered model explains the decrease of threshold electric field due to the increasing field enhancement coefficient; the increase of current density due to the decreasing work function; the improvement of working stability due to smoothing surface roughness. The method for pre-breakdown formation of the films was proposed.