Growth and electron field emission properties of ultrananocrystalline diamond on silicon nanostructures

The electron field emission (EFE) properties of Si nanostructures (SiNS), such as Si nanorods (SiNR) and Si nanowire (SiNW) bundles were investigated. Additionally, ultrananocrystalline diamond (UNCD) growth on SiNS was carried out to improve the EFE properties of SiNS via forming a combined UNCD/SiNS structure. The EFE properties of SiNS were improved after the deposition of UNCD at specific growth conditions. The EFE performance of SiNR (turn-on field, E0 = 5.3 V/μm and current density, Je = 0.53 mA/cm2 at an applied field of 15 V/μm) was better than SiNW bundles (turn-on field, E0 = 10.9 V/μm and current density, Je < 0.01 mA/cm2 at an applied field of 15 V/μm). The improved EFE properties with turn-on field, E0 = 4.7 V/μm, current density, Je = 1.1 mA/cm2 at an applied field of 15 V/μm was achieved for UNCD coated (UNCD grown for 60 min at 1200 W) SiNR. The EFE property of SiNW bundles was improved to a turn-on field, E0 = 8.0 V/μm, and current density, Je = 0.12 mA/cm2 at an applied field of 15 V/μm (UNCD grown for 30 min at 1200 W).