Effect of localized electric field on the carrier transport properties of NiO nanofibers

Nickel oxide nanofibers were synthesized using an electrospinning technique. X-ray diffraction revealed the formation of single phase polycrystalline NiO nanofibers when calcined at 600 degrees C. Scanning electron microscopy demonstrated that the average diameter of composite nanofibers dried at 100 degrees C was 400 nm, which decreased to similar to 100 nm for samples calcined at 600 degrees C. The smooth surface of these nanofibers turned highly porous upon burning of the remnant organic constituents (e.g., PVP, acetic acid and other volatile components) and crystallization of the nanofibers upon calcination at 600 degrees C. At higher voltages, the IV curves followed the bulk limited Poole Frenkel (PF) conduction mechanism. The theoretical field lowering coefficient fin, was in good agreement with the experimental Poole Frenkel field lowering coefficient beta(PF),. The variation in field lowering coefficient may be attributed to the presence of localized electric field due to difference in the work function of NiO nanofibers and electrode material.