Field emission from hybrid CuO and CuCO3 nanosystems

Hybrid CuO nanostructures with CuCO3 nanoparticles are grown by simple heating of copper-coated carbon paper in ambient. Various techniques were used to characterize the samples and the relative concentration of CuCO3 nanoparticles formed can be tuned by varying the thickness of copper on carbon paper. Field emission tests show that heated carbon paper ∼400 nm of Cu coating has the optimized field emission properties with the lowest turn-on field (2.1 V/μm) and can achieve a high current density of 1.0 mA/cm2 at 3.2 V/μm. The field emission property of the hybrid nanosystem decreases as the concentration of CuCO3 decreases. UPS measurements show that samples with higher concentration of CuCO3 have lower workfunction as compared to samples with lower concentration of CuCO3. Using the FN equation, samples with higher concentration of CuCO3 are calculated to have higher enhancement factor β and area factor α and this could be due to the higher number of defects and lower work function of CuCO3 nanoparticles. The CuO–CuCO3 hybrid nanosystem shows potential as candidate for future tunable field emission devices.