Control of Interfacial Structure with Precursor Chemistry in Radial Core/Shell Nanowires of Zinc Oxide, Optically-Active Erbium, and Germanium

Abstract

Germanium nanowires (GeNWs) with core−shell structures enhance the long-term chemical and photophysical stability of their surfaces. In this work, the preparation of Ge core nanowires surrounded by a zinc oxide shell containing erbium was achieved through the use of vapor−liquid−solid (VLS) methods followed by vapor transport processes. It is shown that surface reaction conditions considerably affect the morphology, composition, and photoluminescence properties of these nanowires, including, in some cases, the formation of shell alloy phases, such as Zn2GeO4, during annealing. All nanowire products were characterized by a combination of high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and photoluminescence spectroscopy in both the UV/visible and the near-IR spectral regions.

Self-organization of Ge(111)/Al/glass structures through layer exchange in metal-induced crystallization

“…7 According to Huang et al, the lattice structure possibly has a causal relationship with the formation of the Al-Ge-O alloy during growth. 36,37 Note that these planar defects are almost parallel to the substrate owing to the (111) orientation of Ge. Thus, the resulting Ge layer can be useful as an epitaxial template for fabrication of low-defect semiconductor layers.…”

ZnO/ITO core/shell nanostructure electrodes for future prototype solar cell devices

“…For example, Sungjee Kim et al have synthesized both Type-I as well as Type-II quantum dot (QD) structures and observed good quantum yield enhancement in Type-I structures (20%), and shrinkage in Type-II structures (4%). 4 In this direction, a variety of heteronanostructures including InAs/InP, 5 InAs/CdSe, 6 CdSe/CdS, 7,8 CdSe/CdS/Zn 0.5 Cd 0.5 S/ZnS, 9 Si/ZnO, [10][11][12] Si/SiGe, 13,14 GaAs/ GaP, 15,16 TiO 2 /SnO 2 , 17,18 ZnO/Ge, [19][20][21] and CdSe/Si 22 structures have been synthesized by using multidisciplinary methods, and their interesting physical and chemical properties were explored. On the other hand, a few groups have also fabricated PV devices using various heteronanostructures and noticed considerable light conversion efficiency.…”

Visible light enhanced gas sensing of CdSe nanoribbons of ethanol

“…4 In various semiconductors, Te, Ge and CdS nanomaterials have been extensively investigated due to their advantageous electronic, chemical and optical features. 5,6 Besides, researchers have developed various nanostructures, such as nanoparticles, 7 nanotubes, 8 nanoribbons 9 and nanowires, 10 which could significantly improve the sensitivity of gas sensors. Furthermore, some novel techniques, for instance, compositing nanomaterials, 11 doping metal oxides with Fe/Mn/Co, 12,13 applying high electric field across the sensor terminals 14 and illuminating sensors with UV-vis light, 11 have been introduced to develop multi-functional gas sensors.…”