Two-carrier Analysis of a- and m-ZnO Thin Films
ORAL
Abstract
Thin films of a- and m-plane oriented ZnO have been produced, respectively, on r- and m-sapphire substrates, all demonstrating reasonable crystalline qualities as judged by the X-ray diffractornetry. Contrary to most reported, the samples all demonstrated p-type charge carriers determined by Hall measurement using a Quantum Design PPMS system. The I-V curves of All-ZnO p-n junctions all demonstrate the characteristic nature of diodes. These two measurements provide unambiguous evidences of p-type behaviors. However, there are some irregularity in Hall measurement and magneto-resistivity. In order to understand the origin, we conducted a two-carrier analysis of the Hall data taken over a wide range of temperatures (T) and magnetic fields (B). The dependence of Hall resistivity and MR on B as T and the existence of hysteresis, we speculate, possibly reflect the complex atomic defects and their mobile nature in the otherwise largely perfect crystalline lattices.
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