Investigation on mild condition preparation and quantum confinement effects in semiconductor nanocrystals of SnO2

Semiconductor SnO2 nanoparticles are successfully synthesized under mild conditions via a simple sol–gel process. The structural and morphological properties of the as prepared nanoparticles are investigated by powder XRD, SEM and TEM. The TEM and HRTEM images confirm the formation of SnO2 nanoparticles with nearly spherical morphology with low level of agglomerates. The formation of SnO2 quantum dots in the sizes ranging between 3 and 6 nm is clearly evident from the TEM study and their quantum confinement effect is verified by UV–Vis–NIR absorption study. The band gap value of the SnO2 nanopowder is found to be higher than the bulk material by 0.6 eV. The SAED pattern of individual SnO2 nanoparticle confirms the tetragonal rutile structure with good crystalline nature.