Raman spectroscopy and field electron emission properties of aligned silicon nanowire arrays

Arrays of aligned silicon nanowire (SiNW) were synthesized on a silicon (1 0 0) substrate by self-assembling electroless nanoelectrochemistry. Compared with that of bulk crystal silicon, the first-order Raman peak of the silver cap-removed SiNW arrays shows a downshift and asymmetric broadening due to the phonon quantum confinement effects, and intensity enhancement. Field electron emission from the SiNWs was also investigated. The turn-on field was found to be about 12 V/μm at a current density of 0.01 mA/cm2. These highly densified and ordered SiNW arrays can be expected to have favorable applications in vacuum electronic or optoelectronic devices.