A study of the grain size and electric properties of Mn‐doped ZnO thin films grown by plasma‐assisted molecular beam epitaxy

Abstract

In this study, we investigated the effect of manganese (Mn) doping on the grain size and electrical properties of Zn1‐xMnxO films grown on c ‐sapphire substrates by plasma‐assisted molecular beam epitaxy (PAMBE). Compared with the Raman spectra of reference ZnO films grown at the same conditions without Mn‐doping, the Mn related mode is observed and studied. The surface morphology and grain size were investigated by atomic force microscopy (AFM). The results show that the grains become smaller with increasing the Mn doping content. The electric properties including carrier concentration and mobility have been studied by Hall measurements. The decrease in mobility and the increase in resistivity of the samples with higher Mn doping content might be related to an increase of impurity scattering centers. The electric properties of the grain interior and grain boundary have been studied by using impedance spectroscopy (IS). Based on the IS data, we found that the relaxation time increases gradually with increasing Mn doping content. Besides, the activation energy for grain and grain boundary conduction are studied. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Effect of Laser Pulses on Characterization of Zincoxide Thin Film Prepared by PLD

“…the root mean square (RMS) surface roughness increased with increasing film thickness as shown in Figure 5. Which is in accordance with thefindings of other workers [16,17]. Figure 6 shows the short circuit current density Jsc at different laser pulses: 100 pluses, 150 pluses, and 200 pluses Vs. illuminating power nanostructures ZnO, It has been noted that the Jsc has a linearity behavior for all ZnO thin films with increasing the power.…”

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“…XRD peak shows a monotonic shift in the lower 2θ direction with higher milling time (inset of Fig 1). It is probably a reflection of more grain surface disorder and improved occupancy of Mn atoms at the Zn sites [30]. Both of these factors can contribute to the enhancement [30] of resistivity with increased milling time (Table 1).…”

“…It is probably a reflection of more grain surface disorder and improved occupancy of Mn atoms at the Zn sites [30]. Both of these factors can contribute to the enhancement [30] has not been completely saturated; though for samples with higher milling times, the saturation tendencies of magnetization are better. We feel that a competing paramagnetic tendency is dominant for 6 hours milled sample.…”

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