Understanding Synthesis and Characterization of Oxide Semiconductor Nanostructures through the Example of Nanostructured Nickel Doped Hematite

Hematite is an n-type semiconductor, and its semiconducting properties can further be improved by nano-structuring and doping. In several optoelectronic devices, such as thermoelectric and solar cells, both n- and p-type semiconductors are required. The p-type hematite can be synthesized by doping cations, such as Ni2+, Mg2+, Cu2+, and Mn2+. Furthermore, hematite is a weak ferromagnetic material, and its magnetic properties vary with the size of nanoparticles, doping of cations as well as doping concentration. This chapter discusses various properties of nanostructured nickel-doped hematite. As nickel is a ferromagnetic divalent dopant with a high magnetic moment, its doping in hematite together with nano-structuring shows a large variation in both electrical and magnetic properties in nickel.