Porous silicon as a material for enhancement of electron field emission

The influence of parameters of porous layers on silicon tips on the electro n field emission has been investigated in detail. Porous silicon layers obt ained by electrochemical and stain-etching were studied. It was shown that the conditions of porous layer growth and, hence, the parameters of the por ous layer strongly influence the emission current. The improvement of emiss ion characteristics in comparison with those for single-crystalline Si tips (without porous layer) was observed under definite porous layer growth con ditions. At lower emission current densities the non-monotonous behaviour o f current-voltage characteristics was revealed. The influence of the porous silicon layer on the electron field emission was explained by the formatio n of asperities (fibres) on the silicon tips surface. The parameters of fib res, namely, their density, height and thickness depend on the peculiaritie s of porous layer growth. Formation of porous silicon was modelled on the b asis of single-pore approach.