Synthesis and Field-Emission Properties of Ga2O3-C Nanocables

Uniform Ga2O3-C nanocables with an average core diameter of 40 nm, wall thickness of 6 nm, and lengths of up to dozens of (mu)m were generated via co-thermal evaporation of gallium oxide and activated carbon powder. The nanocable formation is discussed based on thermodynamics and crystallography. Gallium oxide and carbon generate gaseous Ga2O and CO at a higher temperature; they then recombine to form Ga2O3 and C. The simultaneous generation of Ga2O3 and C ensures continuous uniform coatings of carbon on gallium oxide nanowires. Field-emission measurements indicated that the nanocables exhibited an unusual sharp increase in emission current density near the threshold field.