Effects of molar ratio of Zn:Sn on the properties of Zn0/Sn0₂ humidity sensor / Noorlaily Samsudin

In this research ZnO thin films prepared by rf magnetron sputtering and ZnO/SnO₂ cubic structure thin films developed by immersion method are reported. The effects of molar ratio Zn:Sn that varies from (1:10, 2:10, 3:10, 4:10) on the ZnO/SnO₂ thin films were characterized by using 2 probe I-V measurement (Keithley 2400) inside a humidity chamber (ESPEC SH-261) for electrical properties. The surface morphology of ZnO/SnO₂ thin films was characterized by using Field Emission Scanning Electron Microscopy (FESEM) (JEOL JSM 6701F). The parameter of molar ratio 4:10 shows high sensitivity and therefore is suitable for humidity sensor application. The size of cubic structure thin films decrease as the molar ratio of Zn:Sn increase.