Antiferromagnetic Magnetic Polaron Formation and Optical Properties of CVD-Grown Mn-Doped Zinc Stannate (ZTO)

The influence of Mn doping on structural, optical, and magnetic behaviors of Mn-doped zinc stannate (ZTO) nanostructures was investigated. Pure and Mn (atomic ratios of 1, 3, and 5%)-doped high-quality Zn2SnO4 nanowires were prepared through the chemical vapor deposition (CVD) technique. It was observed using X-ray diffraction (XRD) and Raman scattering that doped ZTO exhibits a cubic inverse spinel structure, and no peaks of ZnO, SnO, SnO2, and Mn oxides were found. Incorporation of the Mn ion into the ZTO lattice introduced partial antiferromagnetic coupled spins and related magnetism in the nanowires, which caused a clear band-edge luminescence blue shift as compared with the pure one, although the emission longer than 435 nm due to the presence of oxygen vacancies and traps in the lattice keeps minor changes. This blue-shifted emission in the doped nanowire indicates the formation of an antiferromagnetic polaronic exciton, which is seldom identified in the doped semiconductor. This finding in Mn-doped ZTO samples will have some optical applications in the future.