Ultraviolet emission of silicon quantum tips

Silicon tips used as field emitters have dimensions that are within the qua ntum confinement regime. Therefore they can be considered as freestanding s ilicon tips. In this letter, a photoluminescence spectrum of a 100 x 100 ar ray of silicon tips was taken at 10 K. Narrow ultraviolet luminescence peak s were observed. Using the empirical pseudopotential homojunction model, it is demonstrated that these luminescence peaks come from energy levels aris ing from quantum confinement. By fitting the theoretical result to the expe rimental result, we conclude that the luminescence peaks come from Si quant um tips of about 20 Angstrom in width and that they are covered by silicon dioxide. (C) 1999 American Institute of Physics. [S0003-6951(99)03703- 1].