Charge transport in layers of ZnO nanotetrapods and porous nanosheets comparatively investigated by impedance spectroscopy measurements

The charge transport mechanisms are investigated in layers made of either ZnO nanotetrapods (TPs) grown by vapour phase processes or mesoporous ZnO nanosheets (NSs) obtained from hybrid organic-inorganic precursor nanostructures. In particular, the response of gas sensing devices exploiting these nanostructures is studied by impedance spectroscopy for different gases at different temperatures. It is shown that, in spite of the huge differences in the nanostructure shapes and dimensions, the same equivalent circuit provides an excellent description of the impedance of both the TPs-based and the NSs-based sensors, for all the conditions considered.