High-field magnetotransport in Cu2ZnGeS4 single crystals
| Autor: | S. Levcenko, E. Hajdeu-Chicarosh, Erkki Lähderanta, Maxim Guc, M. A. Shakhov, K. G. Lisunov, Ernest Arushanov, I. Zakharchuk |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Magnetoresistance Condensed matter physics Renewable Energy Sustainability and the Environment Fermi level 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Thermal conduction 01 natural sciences Acceptor 0104 chemical sciences Magnetic field symbols.namesake Electrical resistivity and conductivity Hall effect symbols General Materials Science Charge carrier 0210 nano-technology |
| Zdroj: | Solar Energy. 172:184-190 |
| ISSN: | 0038-092X |
| DOI: | 10.1016/j.solener.2018.04.043 |
| Popis: | The quaternary chalcogenides, attracting much attention in recent time as promising solar energy materials, permit an effective optimization of their composition by the Ge incorporation. In particular, this implies an interest to the Cu2ZnGeS4 compound, which utilization requires, however, a deeper understanding of its electronic properties in general. Here, we investigate magnetotransport of the p-type Cu2ZnGeS4 single crystals, including resistivity, ρ (T), magnetoresistance (MR) and Hall effect, in pulsed magnetic fields up to B = 20 T. The Mott variable-range hopping charge transfer has been established within a broad temperature interval of T between ∼100 and 200 K by investigations of ρ (T) in zero field. The positive and negative contributions to MR have been observed, attributing them to shrinkage of the impurity wave functions by the magnetic field and to the destructive interference of the hopping charge carriers, respectively. Observation of the negative Hall coefficient, RH (T), exhibiting the dependence close to that of ρ (T), gives a strong support to the Mott conduction mechanism in our p-type Cu2ZnGeS4 material. In addition, the conductivity, connected with thermal activation of holes on the mobility edge, Ec, has been identified both below and above the Mott conduction interval. Finally, the joint analysis of the ρ (T) and MR data has yielded a series of important microscopic parameters. These include such details of the hole spectrum in the acceptor band, as its semi-width, W, the density of localized states, g (μ), at the Fermi level, μ, the positions of μ and Ec, as well as values of the localization radius of holes, a, and of the acceptor concentration, NA. |
| Databáze: | OpenAIRE |
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