Effect of growth duration to the electrical properties of Zn doped SnO2 thin film toward humidity sensor application

Abstract

This technical paper investigates the electrical properties of the Zinc doped SnO2 (Zn-doped SnO2) nanostructures that have been prepared by the immersion method by different period of immersion process. The experiment was conducted in 3 different time constraint. The thin films were characterized by using current-voltage (I-V) measurement (Keithley 2400). The results analyzed were for time duration of 6, 12 and 24 hour. At initial stage, the substrate which is a glass was deposited by ZnO using RF magnetron sputtering method. Zn has been doped by SnO2 using immersion process. The optical and structural properties has been characterized using photoluminescence (PL) measurement (Horiba Jobin Yvon-DU420A-OE-325 system) and field emmision scanning electron microscopy (FESEM) (JEOL JSM 6701F) respectively. The sensor were characterized using I-V measurement (Keithley 2400) in a humidity chamber (ESPEC SH-261) and the chamber has been set at same room temperature (25°C) but different percent relative humidity (RH %) at 40 RH% to 90 RH. The highest sensitivity was resulted at 24 hours immersion process. PL measurement revealed one peak at about between range red emission for all Zn-doped SnO2 thin film while for ZnO catalyst reveal two peaks at UV region (380 nm) and visible range (600 nm). FESEM image show the possible growth of nanoparticle and nanocube Zn-doped SnO2 growth on the nucleation site of ZnO catalyst.