Band gap energy modifications observed in trivalent In substituted nanocrystalline SnO_2

摘要

The effect of In doping concentration on the optical band gap of nano-SnO_2 is investigated as a function of calcination temperature. Changes in the band gap explain the room temperature H_2 gas sensing of doped nano-SnO_2. The band gap was found to be lower than those reported for SnO_2 (3.6 eV) from 2.55 to 3.43 eV and may be explained by the presence of nonequilibrium oxygen vacancies in the oxide lattice and band bending effects at the nanoscale.