Structural and optical properties in defect induced SnO2 and Sn0.95Nb0.05O2 nanocrystallites

Intrinsic crystal defects like metal or oxygen vacancies and extrinsic defects like impurity dopants in a metal oxide semiconductor play a crucial role and alter the several structural and optical properties. In the present work, we have successfully synthesized pure and 5% Nb-doped SnO2 nanocrystalline powder using very convenient and less expensive solid-state reaction route. Influence of Nb incorporation and defects on the structural and optical parameters like lattice constants, lattice strain, average crystallite size, optical band gap, defect energy, etc. has been studied. The average crystallite size, lattice constants, and lattice strain are found to be high in the Nb-doped SnO2 as compared to pure SnO2. The optical bandgap of the pure SnO2 was found to be 3.82 eV and increased to 3.92 eV on the incorporation of the Nb content. Defect energy was found to be 0.26 eV in the pure SnO2 and 0.27 eV in Sn0.95Nb0.05O2.