Abstract
The influence of nickel (Ni) doping concentrations on structural, optical, electrical and diode properties of molybdenum trioxide (MoO3) thin films has been studied systematically. Ni-doped MoO3 films and diodes were prepared for various doping concentrations of Ni such as 0, 3, 6 and 9 wt.% by jet nebulizer spray (JNS) pyrolysis technique. The structural properties of Ni-doped MoO3 films were analyzed by X-ray diffraction (XRD) pattern and scanning electron microscopy (SEM). The prepared films were exhibited in the orthorhombic crystal structure and sub-microsized plate-like surface morphology. The energy-dispersive X-ray spectroscopy (EDX) analysis confirmed the presence of Ni, Mo and O elements in the prepared films. Ultraviolet-visible (UV-vis) analysis results showed that the absorbance decreases with the increasing of Ni doping concentration and the minimum band gap energy (E-g=2.25) was obtained for 9 wt.% Ni-doped MoO3 film. From current-voltage (I-V) characterization, the conductivity is increased by increasing the Ni doping concentration in MoO3 thin films. The diode measurements were performed in darkness and under light illumination of a halogen lamp. The methods of I-V, Cheung's and Norde were used to calculate the diode parameters of ideality factor (n), barrier height (Phi (b)) and sheet resistance (R-s). Also, the light ON/OFF switching response of the fabricated n-NiMoO3/p-Si diodes was analyzed.