X-RAY DIFFRACTION ANALYSIS, OPTICAL CHARACTERISTICS AND ELECTRO-PHYSICAL PROPERTIES OF THE N-ZnO/P-NiO STRUCTURE GROWN BY THE SPRAY PYROLYSIS METHOD

This paper presents X-ray diffraction studies, optical and electrophysical properties of n-ZnO/p-NiO structures. The analysis showed that the ZnO film surfaces exhibit a hexagonal crystal structure, characterized by lattice parameters a = b = 0.3265 nm and c = 0.5212 nm. The deposited NiO films belong to the spatial group Fm3m with lattice parameters of 0.4178 nm. It has been found that the sizes of the subcrystallites of the NiO films were 22.3 nm, 29.3 nm and 16.9 nm, respectively. The grown ZnO and NiO films have a high transmittance coefficient from 74% to 92% and from 56% to 68% in the visible and near-infrared regions of the spectrum, respectively. The optical bandgaps were calculated as 3.27 eV for ZnO, 3.81 eV for NiO and 3.26 eV for the combined ZnO/NiO structure. The volt-ampere characteristics and capacitance-voltage analysis indicate that the n-ZnO/p-NiO structure forms regions with high specific resistances at the heterojunction, with potential for applications in LEDs, solar cells and sensors due to its favorable optical and electrical properties.