Photoluminescence and gas sensing study of nanostructured pure and Sn doped ZnO

The nanostructured pure and Sn doped ZnO have been synthesized by the thermal evaporation technique. The influence of Sn on the morphology and structure is investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis techniques. The SEM images indicate change in the growth pattern from nanowires of pure ZnO to tetrapods for Sn doped ZnO. Pure ZnO nanowires exhibit selective response towards acetone vapors while on Sn doping the response decreases. The non-stiochiometry and the morphology of ZnO are probably responsible for such a difference in gas response. However increase in temperature doesn't improve the sensing behavior. The photoluminiscence (PL) studies reveal UV emission in pure ZnO which shifts to green emission on doping of Sn.