It is shown that there is a strong correlation between the emission efficiency and silicon nanostructure in a porous polysilicon(PPS) cold cathode. Nondoped polysilicon layer is formed on an n-type<100>silicon wafer and anodized in a solution of HF(50%):ethanol=1:1 under illumination by a 500 Wtungsten lamp. Subsequently, a PPS layer is oxidized in a rapid thermal oxidation(RTO) furnace for 1 hour at a temperature of 900 C.A thin Au film is deposited onto the PPS layer as a positive electrode. The silicon nanostructures are evaluated by photoluminescent spectra. The PPS which has luminescent peak from Si nanocrystallites shows higher emission efficiency. This result supports our multitunneling model which leads to generate quasi-ballistic electron in a PPS cold cathode.
