Rapid, Low-Temperature Synthesis of Germanium Nanowires from Oligosilylgermane Precursors

Abstract

Type of publicationArticle (peer-reviewed) Link to publisher's versionhttp://dx.doi.org/10.1021/acs.chemmater.7b00714Access to the full text of the published version may require a subscription. 1032112; E-mail: christoph.marschner@tugraz.at; j.holmes@ucc.ie Rights AbstractNew oligosilylgermane compounds with weak Ge-H bonds have been used as precursors for the rapid synthesis of germanium (Ge) nanowires in high yields (>80 %), via a solution-liquid-solid (SLS) mechanism, using indium (In) nanoparticles as a seeding agent over a temperature range between 180 to 380 °C. Even at low growth temperatures, milligram quantities of Ge nanowires could be synthesized over a reaction period of between 5 to 10 minutes. The speed of release of Ge(0) into the reaction environment can be tuned by altering the precursor type, synthesis temperature and the presence or lack of an oxidizing agent, such as tri-n-octylphosphine oxide (TOPO). Energy dispersive X-ray analysis showed that silicon 2 atoms from the precursors were not incorporated into the structure of the Ge nanowires. As both In and Ge facilitate reversible alloying with Li, Li-ion battery anodes fabricated with these nanowires cycled efficiently with specific capacities, i.e. >1000 mAh g -1

Uniformly Confined Germanium Quantum Dots in 3D Ordered Porous Carbon Framework for High‐Performance Li‐ion Battery

“…For the following cycles, the three cathodic peaks between 0.1 and 0.7 V correspond to the formation of different LixGe alloys (Li 9 Ge 4 , Li 7 Ge 2 , Li 15 Ge 4 , and Li 22 Ge 5 ), [ 5b ] whereas the peaks located between 0.25 and 0.75 V in the oxidation scan can be ascribed to the de‐alloying reactions during which LixGe alloys experience the extraction of lithium and eventually transform into germanium. [ 19 ] As control, the Ge/NC anode shows similar CV curve shapes to the 3DOP Ge@NC anode but slightly different voltage peak values (Figure S5, Supporting Information), implying that the control Ge/N–C anode has a similar lithium storage mechanism but inferior reversibility.…”

A Review of Self-Seeded Germanium Nanowires: Synthesis, Growth Mechanisms and Potential Applications

“…Cd and Tl are not very suitable for Ge nanowire growth due to droplet–nanowire system surface tension, a crucial element in nanowire growth. Group III, i.e., Ga [ 114 ] and In [ 115 ], IV, i.e., Sn [ 116 ] and Pb [ 117 ] and V, i.e., Sb [ 40 ] and Bi [ 118 ], elements are much more interesting as seed materials due to their low eutectic temperatures while having potential doping capacities as both n-type and p-type dopants. Type C catalysts, e.g., Cu [ 119 ] and Ni [ 120 ], are of particular interest due to their compatibility with group IV materials, and thus, potential integration in the Complementary Metal–Oxide–Semiconductor (CMOS) industry [ 121 ].…”

Applications of Low‐Melting‐Point Metals in Rechargeable Metal Batteries

“…Electrochemical intercalation of Li into these intermetallic compounds involves the non‐steady‐state Li diffusion in solid electrodes. Ge‐In nanowires were synthesized through In nanoseeds at elevated temperatures [18e] . As both In and Ge could reversibly alloy with Li, such anodes deliver a high specific capacity of >1000 mAh g −1 .…”