Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/22825
Title: Growth and characterization of Germanium and Silicon Nanostructures
Authors: HUANG JINQUAN
Keywords: Growth, Characterization, Germanium, Silicon, Nanostructures
Issue Date: 19-Jul-2010
Source: HUANG JINQUAN (2010-07-19). Growth and characterization of Germanium and Silicon Nanostructures. ScholarBank@NUS Repository.
Abstract: In this dissertation, the growth and characterization of five different types of germanium (Ge) and silicon (Si) nanostructures are presented. The nanostructures include one-dimensional Ge nanowires (GeNWs), GeSi oxide nanotubes (GeSiOxNTs), heterostructures of GeNW-GeSiOxNT, Si nanowires (SiNWs) and near zero-dimensional Ge nanodots (GeNDs). The first three were obtained using bottom-up approaches where the materials were self-assembled together with the aid of metal catalysts. The formation of the SiNWs, on the other hand, was by a top-down process making use of metal nanodots formed using an anodized aluminium oxide (AAO) template. AAO was also utilized as a thermal evaporation mask for the deposition of the regular arrays of GeNDs. The formation mechanism of each type of nanostructure was investigated in detail. GeNWs were obtained via the vapour-liquid-solid growth catalyzed by active gold (Au) droplets. On the other hand, the formation of the GeSiOxNTs required passivation of the Au catalyst so that growth was limited to the rims of the Au dots. Consequently, the GeNW-GeSiOxNT heterostructure was a result of timely control of the Au passivation such that formations of hollow tubes and solid wires took place at different time. For the top-down fabrication of SiNWs, uniform and well-aligned SiNWs were produced by chemical wet etching using AAO-templated chromium/gold nanodots as a hard mask blocking material. This dissertation also explored some unique properties of the as-synthesized nanostructures. In particular, thermal conductance measurements have shown that the wire-tube heterostructure demonstrated a thermal rectification as high as 6%. The different charge-trapping characteristics of the GeNDs were also studied using the scanning capacitance microscopy technique.
URI: http://scholarbank.nus.edu.sg/handle/10635/22825
Appears in Collections:Ph.D Theses (Open)

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
HuangJQ_Growth & Characterization of Germanium & Silicon Nanostructures.pdf10.42 MBAdobe PDF

OPEN

NoneView/Download

Page view(s)

319
checked on Dec 11, 2017

Download(s)

440
checked on Dec 11, 2017

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.