Low voltage field emission from PbZr0.2Ti0.8O3-coated silicon nanotips

We report field emission from nanometer-sharp tips of polarized PbZr_0.2Ti_0.8O₃ (PZT) and silicon. The ferroelectric PZT emitters are a high-density array of single-crystal silicon tips that are coated with a 30 nm thick film of crystalline PZT in a batch fabrication process. The PZT emitter tips begin to emit electrons at fields as low as 2 V/μm and reach threshold emission at fields as low as 3.9 V/μm. This is considerably lower than the threshold field of 7.2 V/μm for uncoated silicon emitter tips. This improvement is about one order of magnitude improvement over previous publications for silicon tips. Using a Fowler-Nordheim analysis, we calculate the effective work function of the PZT film to be 1.00 eV and the field amplification factor to be 1525.