Effect of the propanol-water volume ratios on the properties of SnO sub(2) nanocrystals

Herein we report on the tuning of the morphologies of SnO sub(2) nanocrystals (NCs) by varying the water-propanol volume ratios during the microwave synthesis. Our results show the change in morphology from spherical, when pure water is a solvent, to oriented attachment and then nanotubes, as the solvent mixture is increased from 1:1 to 2:3 to 3:2 propanol-water volume ratios. Furthermore electrical properties of solution processed thin films of the as-prepared SnO sub(2) NCs were investigated. The 2:3 ratio sample showed the lowest resistivity of 0.95 m[Omega] cm. Annealing of the sample at different temperatures had an effect in electrical properties with an oscillatory trend with annealing temperature being observed. In addition there was an initial decrease in particle size upon annealing and the oriented attachment mechanism seen at room temperature was dismantled. There was subsequent increase in particle size with an increase on temperature due to Ostwald ripening.