Metal-insulator transition in epitaxial Ga-doped ZnO films via controlled thickness.
作者： Joynarayan Mukherjee , B R K Nanda , M S Ramachandra Rao
关键词: Thin film 、 Metal–insulator transition 、 Pulsed laser deposition 、 Weak localization 、 Magnetoresistance 、 Electron mobility 、 Variable-range hopping 、 Electrical resistivity and conductivity 、 Condensed matter physics 、 Materials science
摘要: Understanding and tuning of metal-insulator transition (MIT) in oxide systems is an interesting active research topics condensed matter physics. We report thickness dependent MIT Ga-doped ZnO (Ga:ZnO) thin films grown by pulsed laser deposition technique. From the electrical transport measurements, we find that while thinnest film (6 nm) exhibits a resistivity 0.05 Ω cm, lying insulating regime, thickest (51 has 6.6 × 10-4 cm which shows metallic type conduction. Our analysis reveals Mott's variable range hopping model governs behavior 6 nm whereas 2D weak localization (WL) phenomena appropriate to explain electron thicker Ga:ZnO films. Magnetoresistance study further confirms presence strong WL observed 20 above density functional calculations, it found due surface reconstruction Ga doping, crystalline disorder sets very introduce localized states thereby, restricts donor mobility.
harvard.edu
sci-hub.st 参考文章(49)
Marek Pękała, Nadezda Kozlova, Vadym Drozd, Comparison of magnetotransport properties of nano- and microcrystalline La0.7Ca0.3MnO3 manganites in high magnetic field Journal of Applied Physics. ,vol. 104, pp. 123902- ,(2008) , 10.1063/1.3040013
N. Sharma, S. Granville, S. C. Kashyap, J.-Ph. Ansermet, Low-temperature hopping and absence of spin-dependent transport in single crystals of cobalt-doped ZnO Physical Review B. ,vol. 82, ,(2010) , 10.1103/PHYSREVB.82.125211
H. Okamoto, Y. Hamakawa, Electronic behaviors of the gap states in amorphous semiconductors Solid State Communications. ,vol. 24, pp. 23- 27 ,(1977) , 10.1016/0038-1098(77)90557-9
John P. Perdew, Kieron Burke, Matthias Ernzerhof, Generalized Gradient Approximation Made Simple Physical Review Letters. ,vol. 77, pp. 3865- 3868 ,(1996) , 10.1103/PHYSREVLETT.77.3865
Amit K. Das, R. S. Ajimsha, L. M. Kukreja, Thickness dependent metal-insulator transition and dimensional crossover for weak localization in Si0.02Zn0.98O thin films grown by pulsed laser deposition Journal of Applied Physics. ,vol. 115, pp. 193705- ,(2014) , 10.1063/1.4878698
V. Bhosle, A. Tiwari, J. Narayan, Electrical properties of transparent and conducting Ga doped ZnO Journal of Applied Physics. ,vol. 100, pp. 033713- ,(2006) , 10.1063/1.2218466
Arpana Agrawal, Tanveer A. Dar, Pratima Sen, Deodatta M. Phase, Transport and magnetotransport study of Mg doped ZnO thin films Journal of Applied Physics. ,vol. 115, pp. 143701- ,(2014) , 10.1063/1.4870864
J. Hüpkes, B. Rech, O. Kluth, T. Repmann, B. Zwaygardt, J. Müller, R. Drese, M. Wuttig, Surface textured MF-sputtered ZnO films for microcrystalline silicon-based thin-film solar cells Solar Energy Materials and Solar Cells. ,vol. 90, pp. 3054- 3060 ,(2006) , 10.1016/J.SOLMAT.2006.06.027
F. Reuss, S. Frank, C. Kirchner, R. Kling, Th. Gruber, A. Waag, Magnetoresistance in epitaxially grown degenerate ZnO thin films Applied Physics Letters. ,vol. 87, pp. 112104- ,(2005) , 10.1063/1.2045553
D. C. Look, K. D. Leedy, L. Vines, B. G. Svensson, A. Zubiaga, F. Tuomisto, D. R. Doutt, L. J. Brillson, Self-compensation in semiconductors: the Zn-vacancy in Ga-doped ZnO Physical Review B. ,vol. 84, pp. 115202- ,(2011) , 10.1103/PHYSREVB.84.115202