Pranay K. Sen | Searcharxiv

arXiv2017

Temperature induced transition from p-n to n-n electronic behavior in Ni0.07Zn0.93O/Mg0.21Zn0.79O heterojunction

The transport characteristics across the pulsed laser deposited Ni0.07Zn0.93O/Mg0.21Zn0.79O heterojunction exhibits p-n type semiconducting properties at 10 K while at 100 K, its characteristics become similar to that of an n-n junction. The reason for the same is attributed to the role of larger electronegativity of Ni as compared to Mg at 10 K and ionization of impurity states at 100 K. The above behavior is confirmed by performing the Hall measurements.

cond-mat.mtrl-sci↗

arXiv2017

Sign reversal of magnetoresistance and p to n transition in Ni doped ZnO thin film

We report the magnetoresistance and nonlinear Hall effect studies over a wide temperature range in pulsed laser deposited Ni0.07Zn0.93O thin film. Negative and positive contributions to magnetoresistance at high and low temperatures have been successfully modeled by the localized magnetic moment and two band conduction process involving heavy and light hole subbands, respectively. Nonlinearity in the Hall resistance also agrees well with the two channel conduction model. A negative Hall voltage has been found for T $\gte 50 K$, implying a dominant conduction mainly by electrons whereas positive Hall voltage for T less than 50 K shows hole dominated conduction in this material. Crossover in the sign of magnetoresistance from negative to positive reveals the spin polarization of the charge carriers and hence the applicability of Ni doped ZnO thin film for spintronic applications.

cond-mat.mtrl-sci↗