3D Networks of Ge Quantum Wires in Amorphous Alumina Matrix

Abstract

Recently demonstrated 3D networks of Ge quantum wires in an alumina matrix, produced by a simple magnetron sputtering deposition enables the realization of nanodevices with tailored conductivity and opto-electrical properties. Their growth and ordering mechanisms as well as possibilities in the design of their structure have not been explored yet. Here, we investigate a broad range of deposition conditions leading to the formation of such quantum wire networks. The resulting structures show an extraordinary tenability of the networks’ geometrical properties. These properties are easily controllable by deposition temperature and Ge concentration. The network’s geometry is shown to retain the same basic structure, adjusting its parameters according to Ge concentration in the material. In addition, the networks’ growth and ordering mechanisms are explained. Furthermore, optical measurements demonstrate that the presented networks show strong confinement effects controllable by their geometrical parameters. Interestingly, energy shift is the largest for the longest quantum wires, and quantum wire length is the main parameter for control of confinement. Presented results demonstrate a method to produce unique materials with designable properties by a simple self-assembled growth method and reveal a self-assembling growth mechanism of novel 3D ordered Ge nanostructures with highly designable optical properties.

Multiple Exciton Generation in 3D-Ordered Networks of Ge Quantum Wires in Alumina Matrix

“…The interconnection is well visible in the microscopy measurements published in Ref. [ 21 ] and additionally confirmed by Ge desorption from this type of materials as shown in Ref. [ 22 ].…”

“…They reveal the formation of an ordered Ge QW network, as explained in detail in Ref. [ 21 ]. The scheme of the formed QWs and their ordering in a QW network is illustrated in Figure 2 d. The nodes of the QW network are ordered in a body-centered tetragonal lattice, and the QWs are interconnected.…”

Deposition of Thin Alumina Films Containing 3D Ordered Network of Nanopores on Porous Substrates

“…From the results, we can see that the nanopore radius (R) is around 0.6 nm for all the films. This is due to the same deposition temperature for all the films, as shown in the case of Ge quantum wires in [46]. The deposition time (D1-D3) only significantly influences the thickness of the films (D), assuming a constant Ge sputtering power (P1), while the pore length (L) depends on the Ge sputtering power during the film preparation (P1-P3).…”

“…The film grows homogeneously with the same value of the pore length. More information about the production of Ge quantum wire lattices with different structural parameters is given in [46]. Table 2.…”

Structural, Optical and Electrical Properties of Al+MoO3 and Au+MoO3 Thin Films Prepared by Magnetron Codeposition

“…The dimensionality of functional materials, for example one, two and three dimensional, has been demonstrated as a dominant factor in determining the performance of the resulting applications [ 15 ]. Zero dimensional quantum dots (QDs) [ 16 , 17 ], one dimensional nanofibers/nanotubes/nanorods [ 18 ], two dimensional layered semiconductors/insulators [ 19 ] and three dimensional complex structures [ 20 ] have recently shown the most attractive features in terms of structural, optical, electrical and mechanical characteristics, thus creating the conditions for significant technological breakthroughs.…”