Growth of Narrow and Straight Germanium Nanowires by Vapor–Liquid–Solid Chemical Vapor Deposition

Abstract

This paper describes the growth of germanium nanowires (Ge NWs) via vapor–liquid–solid (VLS) mechanism by the low-pressure chemical vapor deposition (CVD) technique. A systematic study of the growth conditions of the Ge NWs has been conducted by varying the size of the Au nanoparticles and the substrate temperature. The tapering of the nanowires has been minimised when the growth temperature is lowered from 300 to 280 °C which also contributes to the decrease in the diameter of the Ge NWs. The growth temperature of 280 °C yields Ge NWs with diameters of less than 5 nm, offering an opportunity for the fabrication of high-performance germanium nanowire field-effect transistors.

Array geometry dictates electrochemical performance of Ge nanowire lithium ion battery anodes

“…For the case of VLS Ge nanowires, parasitic islands near the current collector were reported in a range of studies. [60][61][62][63][64][65] In our samples, with increasing growth time and with a higher growth temperature the parasitic Ge layers thickened.…”

“…This study is also the rst to examine the role of the parasitic thin lm layer sitting at the base of the nanowire arrays in establishing the cycling performance of Ge nanowires. Parasitic lms are widely reported in literature for VLS grown Si and Ge nanowires [59][60][61][62][63][64][65] and have been recently examined by Picraux et al 59 only for the case of Si. However their role remains unexplored for the fundamentally different case of Ge nanowires.…”

Inherent Control of Growth, Morphology, and Defect Formation in Germanium Nanowires

“…Usually bottom-up synthesis using solid phase catalysts allows control over the aspect ratio, diameter and structure of one-dimensional (1D) crystals, through the control over external parameters such as precursor feedstock, temperature, operating pressure and precursor flow rate. 7,[19][20][21][22][23] Ge nanowires from twinned seed particles. 31 The density of planar defects in the collector seed particles can potentially be varied by alloying seeds with different intermetallic compositions.…”

Recent advances in the growth of germanium nanowires: synthesis, growth dynamics and morphology control

“…Vapour and liquid-based growth of Ge nanowires consists of any method where the Ge precursor is in either vapour and liquid form and include techniques such as chemical vapour deposition (CVD) [45][46][47][48][49][50] , metal-organic chemical vapour deposition (MOCVD) 51 52 , molecular beam epitaxy [53][54][55] , template methods 56,57 and various evaporation methods such as electron beam evaporation 58,59 and thermal evaporation 60,61 . Alternatively, liquid/solution (see figure 1) 14,52,[62][63][64][65][66][67] and SCF [68][69][70][71][72] based methods involve the introduction of precursors in liquid and supercritical media respectively.…”

“…OAG essentially involves the evaporation and deposition of an oxide vapour to form crystalline nanowires wrapped in an amorphous oxide shell, which prevents radial growth and tapering, thus yielding nanowires with a constant diameter. In contrast to the two-temperature method, the more facile single temperature methods have been used by Simanullang et al to grow very thin (less than 5 nm) taper-free Ge nanowires 50,90 . Vertically aligned epitaxial Ge nanowires have also been achieved using bio-templated Au nanoparticles.…”