Controlled Growth of Ternary Alloy Nanowires Using Metalorganic Chemical Vapor Deposition

Abstract

We report the growth and characterization of ternary AlxGa1- xAs nanowires by metalorganic chemical vapor deposition as a function of temperature and V/III ratio. Transmission electron microscopy and energy dispersive X-ray spectroscopy show that, at high temperatures and high V/III ratios, the nanowires form a core-shell structure with higher Al composition in the nanowire core than in the shell. We develop a growth model that takes into account diffusion of reactants and decomposition rates at the nanowire catalyst and stem to describe the compositional difference and the shell growth rate. Utilizing this model, we have successfully grown compositionally uniform Al0.16Ga0.84As nanowires. The ability to rationally tune the composition of ternary alloy nanowires broadens the application range of nanowires by enabling more complex nanowire heterostructures.

Electronic structure and optical properties of CdSxSe1−x solid solution nanostructures from X-ray absorption near edge structure, X-ray excited optical luminescence, and density functional theory investigations

“…One goal is to have the ability to control the composition of semiconductor alloys and effectively tune the band-gap of a material for a specific function. As a result, various ternary alloys have recently attracted a great deal of attention for their ability to achieve a wide range of band-gaps, [1][2][3][4][5][6][7][8][9][10][11][12] Additionally, nano-materials, such as nano-wires and nano-ribbons, offer greater versatility by providing a wider range of alloy composition and band-gap modulation which is unachievable using traditional epitaxial film materials due to lattice strain at the substrate interface. 13 Ternary chalcogenide semiconductors, particularly cadmium sulpho-selenide (CdS x Se 1Àx ) alloys, have been intensely studied 8,[14][15][16][17][18][19] in part due to the remarkably broad range of stable stoichiometries that can be attained, owing to the small lattice mismatch among the constituent anions.…”

XX Международный симпозиум Нанофизика и наноэлектроника", Нижний Новгород, 14-18 марта 2016 г. Гибридные нитевидные нанокристаллы AlGaAs/GaAs/ AlGaAs с квантовой точкой, полученные методом молекулярно-пучковой эпитаксии на поверхности кремния

“…Следует отметить, что подобное образование самоорганизован-ной структуры типа " стержень-оболочка" ранее упоми-налось как при МПЭ [8], так и газофазной эпитаксии [9]. Однако приведенные результаты противоречат друг дру-гу.…”

“…Однако приведенные результаты противоречат друг дру-гу. Так, в первом случае, как и в данной работе, мольный состав x у оболочки был выше, чем у стержня, в то время как в работе [9] -наоборот. Детальный анализ причин, приводящих к подобному феномену, приведен в отдельной статье [10].…”

MOVPE Self-Assembly and Physical Properties of Free-Standing III-V Nanowires

“…Today the MOVPE self-assembly of III-V nanowires is studied by several research groups, which however, in most cases use colloidal Au NPs as catalysts for the VLS growth. To date the Au-catalyst assisted MOVPE of III-V nanowires has been extended to ternary alloys, such as GaAsP , GaInP (Sköld et al, 2005), and InGaAs (Regolin et al, 2006), while only few data can yet be found on the catalyst-assisted MOVPE of AlGaAs nanowires (Lim et al, 2008). For these ternary alloys a major challenge is to growth nanowires with uniform composition along both their major axis and in the radial direction (Regolin et al, 2006;Kim et al, 2006;& Lim et al, 2008).…”

“…To date the Au-catalyst assisted MOVPE of III-V nanowires has been extended to ternary alloys, such as GaAsP , GaInP (Sköld et al, 2005), and InGaAs (Regolin et al, 2006), while only few data can yet be found on the catalyst-assisted MOVPE of AlGaAs nanowires (Lim et al, 2008). For these ternary alloys a major challenge is to growth nanowires with uniform composition along both their major axis and in the radial direction (Regolin et al, 2006;Kim et al, 2006;& Lim et al, 2008). The MOVPE growth of nanowires with modulation of the material composition in either the axial or radial direction has been also demonstrated for a number of III-V systems.…”