Study of dark-conductivity and photoconductivity of ZnO nano structures synthesized by thermal decomposition of zinc oxalate

In the present work, zinc oxalate [ZnC 2 O 4 ·2H 2 O] was used as precursor to prepare zinc oxide nano structures by thermal decomposition. Its photoconductivity and dark-conductivity properties have been studied in air as well as in vacuum. Voltage dependence of photocurrent and dark-current has been observed at room temperature in air under UV-vis illumination and is found as superlinear in nature. Rise and decay curve in air exhibits anomalous behavior wherein the photocurrent decreases even during steady illumination. In vacuum, the rise of photocurrent becomes slow and prolonged.