Protocol for fabricating optically transparent, pinhole-free NiO thin film for memory devices using the spin-coating technique

Fabricating visibly transparent and uniform metal oxide thin films is a significant challenge. Here, we present a protocol for the fabrication of NiO thin films. We detail the essential steps for substrate preparation. We then describe the optimized steps for spin coating, considering various parameters such as the concentration of the precursor solution, drying temperature, annealing temperature, and spin-coating speed.