Ray Nirat, Gupta Nikita, Adhikary Meghadeepa, Nekić Nikolina, Basioli Lovro, Dražić Goran, Bernstorff Sigrid, Mičetić Maja
School of Physical Sciences, Jawaharlal Nehru University, Delhi, 110067, India.
Department of Materials Science and Engineering, Indian Institute of Technology, Delhi, 110016, India.
Sci Rep. 2019 Apr 1;9(1):5432. doi: 10.1038/s41598-019-41942-3.
We demonstrate formation of material consisting of three-dimensional Germanium nanowire network embedded in an insulating alumina matrix. A wide range of such nanowire networks is produced using a simple magnetron sputtering deposition process. We are able to vary the network parameters including its geometry as well as the length and width of the nanowires. The charge transport in these materials is shown to be related to the nanowire surface per unit volume of the material, α. For low values of α, transport is characterized by space charge limited conduction and a drift of carriers in the extended states with intermittent trapping-detrapping in the localized states. For large values of α, charge transport occurs through hopping between localized electronic states, similar to observations in disorder-dominated arrays of quantum dots. A crossover between these two mechanisms is observed for the intermediate values of α. Our results are understood in terms of an almost linear scaling of the characteristic trap energy with changes in the nanowire network parameters.
我们展示了由嵌入绝缘氧化铝基质中的三维锗纳米线网络组成的材料的形成。使用简单的磁控溅射沉积工艺制备了多种此类纳米线网络。我们能够改变网络参数，包括其几何形状以及纳米线的长度和宽度。这些材料中的电荷传输显示与材料单位体积的纳米线表面α有关。对于α的低值，传输的特征是空间电荷限制传导以及载流子在扩展态中的漂移，同时在局域态中存在间歇性的俘获 - 脱俘获。对于α的高值，电荷传输通过局域电子态之间的跳跃发生，类似于在无序主导的量子点阵列中的观察结果。在α的中间值处观察到这两种机制之间的转变。我们的结果可以通过特征陷阱能量随纳米线网络参数变化的几乎线性缩放来理解。
