Effect of solution flow on the properties of tin dioxide SnO2 thin films deposited by spray pyrolysis technique

In this paper, we investigate the effect of solution flow rate on the structural, optical, and electrical properties of tin dioxide (SnO2) thin films prepared by spray pyrolysis method onto glass substrate. The films deposited at various flow rates ranging from 50 to 175 ml/h with steps of 25 ml/h at 400 °C. Using characterizations techniques, such as X-ray diffraction, which determinate that our films poly crystalline have tetragonal structure, with favorable growth direction (110); the grain size was between 10.08-12.599 nm. However, the films subjected to compressive stresses which caused deformation in the mesh parameter a and dislocation density changed from 6.29*1015 to 9.84*1015 line/m2. While UV-vis showed that a transmittance decrease when the flow rate increase from 85% to 50% approximately, that is because a thickness increase too from 510.17 to 1066.5 nm. We found direct energy band gap between 3.7251 eV for 3.8355 eV with presence of disorder ranging from 609 to 1041 meV. Also the electrical study using four-point technique gave maximum values at 100 ml/h is 45.90 Ω cm.