Structural, electrical and optical properties of transparent conducting SnO2 films: effect of the oxygen flow rate

Pure tin oxide films were deposited onto glass substrate at different oxygen flow rates by a simple and inexpensive method of air pressure chemical vapor deposition. The deposition temperature was kept constant at about 500 degrees C, and oxygen with a flow rate of 0-400 sccm was used as both a carrier gas and the oxidizing agent. Investigation of the electrical parameters variations showed that these parameters vary with oxygen flow rate, reaching an optimum value at the flow rate of 100 sccm. X-ray diffraction (XRD) also revealed the structure to be polycrystalline for all films deposited at different oxygen flow rates. In agreement with the XRD results, field emission scanning electron microscopy micrographs showed a reduction in grain size corresponding to increasing flow rates until 200 sccm, and after that, with a further increase of flow rate, the grain size increased.