Fabrication of ON/OFF switching response based on n-Ni-doped MoO_3/p-Si junction diodes using Ni-MoO_3 thin films as n-type layer prepared by JNS pyrolysis technique

摘要

The influence of nickel (Ni) doping concentrations on structural, optical, electrical and diode properties of molybdenum tri-oxide (MoO_3) thin films has been studied systematically. Ni-doped MoO_3 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 MoO_3 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 MoO_3 film. From current-voltage (I-V) characterization, the conductivity is increased by increasing the Ni doping concentration in MoO_3 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 (Φ_b) and sheet resistance (R_s). Also, the light ON/OFF switching response of the fabricated n-NiMoO_3/p-Si diodes was analyzed.