Enhanced electron field emission of Cu implanted microcrystalline diamond films after annealing

Effects of Cu ions implantation on the structure and electron field emission (EFE) properties of microcrystalline diamond (MCD) films were investigated. The MCD films implanted with Cu ions at a fluence of 1.0 × 1017 ions/cm2 and subsequent annealing in N2 atmosphere at 600 °C for 2 h achieved good electrical conductivity with lower surface resistance of 0.1301 Ω/sq, high carrier concentration of 7.621 × 1018 cm−3 and hall mobility of 62 cm2 V−1s−1. Our results show that Cu nanoparticles can be formed in surface of MCD films after Cu ion implantation and annealing, which induced the formation of graphitic phases during annealing process. Consequently, the presence of Cu nanoparticles and graphitic phase formed conduction channels for efficient electron transport, ensuing better electron field emission (EFE) properties for Cu ion implanted/annealed MCD film with low turn-on field of 2.234 V/μm and high EFE current density of 28.560 μA/cm2 at an applied field of 4.172 V/μm.