Department of Mathematics and Physics, Lappeenranta University of Technology, PO Box 20, FIN-53851, Lappeenranta, Finland.
Institute of Applied Physics, Academy of Sciences of Moldova, Academiei Str. 5, MD-2028, Chisinau, Republic of Moldova.
Sci Rep. 2017 Sep 6;7(1):10685. doi: 10.1038/s41598-017-10883-0.
Recent development of the thin film solar cells, based on quaternary compounds, has been focused on the Ge contain compounds and their solid solutions. However, for effective utilization of CuZnGeS, deeper investigations of its transport properties are required. In the present manuscript, we investigate resistivity, ρ (T), magnetoresistance and Hall effect in p-type CuZnGeS single crystals in pulsed magnetic fields up to 20 T. The dependence of ρ (T) in zero magnetic field is described by the Mott type of the variable-range hopping (VRH) charge transfer mechanism within a broad temperature interval of ~100-200 K. Magnetoresistance contains the positive and negative components, which are interpreted by the common reasons of doped semiconductors. On the other hand, a joint analysis of the resistivity and magnetoresistance data has yielded series of important electronic parameters and permitted specification of the CuZnGeS conductivity mechanisms outside the temperature intervals of the Mott VRH conduction. The Hall coefficient is negative, exhibiting an exponential dependence on temperature, which is quite close to that of ρ(T). This is typical of the Hall effect in the domain of the VRH charge transfer.
近年来，基于四元化合物的薄膜太阳能电池的发展集中在含锗化合物及其固溶体上。然而，为了有效利用 CuZnGeS，需要对其输运性质进行更深入的研究。在本论文中，我们在脉冲磁场高达 20T 的条件下研究了 p 型 CuZnGeS 单晶体的电阻率 ρ（T）、磁电阻和霍尔效应。在零磁场下，ρ（T）的依赖性可以用变程跳跃（VRH）电荷转移机制的莫特类型来描述，该机制在约 100-200K 的宽温度范围内适用。磁电阻包含正、负分量，这可以用掺杂半导体的共同原因来解释。另一方面，对电阻率和磁电阻数据的联合分析得出了一系列重要的电子参数，并允许在莫特 VRH 传导的温度间隔之外指定 CuZnGeS 的传导机制。霍尔系数为负值，表现出对温度的指数依赖性，这与 ρ(T) 非常接近。这是 VRH 电荷转移领域中霍尔效应的典型特征。
