An Evaluation of Structural, Topographic, Optical, and Temperature-Dependent Electrical Features of Sol–Gel Spin-Coated p-NiO/n-Si Heterojunction

p-NiO/n-Si heterodiode was deposited with an easy and cheap sol–gel route using a spin coater. The XRD results revealed that NiO film had polycrystalline cubic bunsenite structure with (200) preferential direction. The AFM and SEM micrographs indicated that the film was composed of homogenously distributed nanoparticles on n-Si surface. The uniform scattering of Ni and O elements was also seen from EDX mapping pictures. The band gap value for NiO sample was found to be 3.74 eV. The current–voltage (I–V) properties of Ag/p-NiO/n-Si heterojunction were inquired in the temperature range of 80 K to 300 K (−193 °C to 27 °C). The temperature coefficient of barrier height of the Ag/p-NiO/n-Si heterojunction was determined to be 2.6 meV/K. The I-V measurements showed that the barrier height of the heterojunction increased with an increment in the temperature.