High Density Germanium Nanowire Growth Directly from Copper Foil by Self-Induced Solid Seeding

Abstract

Herein, we describe the growth of highly dense germanium nanowire mats directly on copper foil by a self induced, solid seeded protocol. The existence of Cu 3 Ge tips on each of the nanowires indicates that growth proceeds via a solid catalyzed route, dependent on the in situ formation of the germanide intermediate. The nanowires show a tight diameter distribution and typically <110> growth directions resulting from similarities in the d-spacings between the nanowire and the catalyst seed. The nanowires and substrates were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD) scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDX) and electron backscatter diffraction (EBSD).

Growth of Crystalline Copper Silicide Nanowires in High Yield within a High Boiling Point Solvent System

“…In the case of the Ge NWs previously grown in our system from Cu foil, the intermediate Cu germanide phase formed on top of the cubic Cu foil was Cu 3 Ge (orthorhombic). 24 The Ge NWs (cubic) grew on top of the Cu 3 Ge and it was found that the resultant Cu 3 Ge catalyst seeds which remained on the NW tips post-synthesis were oriented such that the lattice spacing of the seed closely matched that of the <110> growth directions of the Ge NWs. Similarly, previous reports using Cu as a seed for elemental Si NW formation have always led the formation of orthorhombic Cu 3 Si catalyst seeds from the initial Cu nanoparticles.…”

Direct growth of germanium and silicon nanowires on metal films

“…35 An interesting new direction in semiconductor NW synthesis methods emerged from the recent work of Ryan and co-workers who demonstrated that Ge NWs can also be grown directly on Cu lms. 36,37 Yuan et al 38 showed that single crystalline Si nanowires can be synthesized on the surface of various bulk metals including Ag, Al, Cu, Fe, Ni, Pb, and Ti. This variation of the VSS growth is particularly attractive for NW applications requiring high-throughput processing and direct integration of NWs into devices through roll-to-roll processing.…”

High-Performance Germanium Nanowire-Based Lithium-Ion Battery Anodes Extending over 1000 Cycles Through in Situ Formation of a Continuous Porous Network

“…10,11 Gold is the most common catalyst for Ge NWs synthesis 4,[12][13][14] , however as it is expensive and does not reversibly alloy with lithium 15 , alternative more cost effective catalyst materials that can contribute to the specific capacity of the electrode are desirable. 16,17 Improving the cycle life of simple Ge NW arrangements as Li-ion anodes would be very interesting as their ease of processability and scalability, particularly if solution grown, can offer viable alternatives to graphitic materials. Reports to-date on binder-free Ge NW electrodes have only shown stability up to 50 cycles.…”