Tin dioxide sensing layer grown on tubular nanostructures by a non-aqueous atomic layer deposition process

A new atomic layer deposition (ALD) process for nanocrystalline tin dioxide films is developed and applied for the coating of nanostructured materials. This approach, which is adapted from non-hydrolytic sol-gel chemistry, permits the deposition of SnO₂ at temperatures as low as 75 °C. It allows the coating of the inner and outer surface of multiwalled carbon nanotubes with a highly conformal film of controllable thickness. The ALD-coated tubes are investigated as active components in gas-sensor devices. Due to the formation of a p-n heterojunction between the highly conductive support and the SnO ₂ thin film an enhancement of the gas sensing response is observed. A new low temperature atomic layer deposition process of nanocrystalline tin dioxide films is developed and applied for the coating of tubular nanostructures. This approach allows the coating of inner and outer surface of multiwalled carbon nanotubes with a highly conformal film of controllable thickness, at temperature as low as 75°C. The obtained heterostructures show enhanced gas sensing responses.