Observation of the Multilayer Growth Mode in Ternary InGaAs Nanowires

Abstract

Au-seeded semiconductor nanowires have classically been considered to only grow in a layer-by-layer growth mode, where individual layers nucleate and grow one at a time with an incubation step in between. Recent in situ investigations have shown that there are circumstances where binary semiconductor nanowires grow in a multilayer fashion, creating a stack of incomplete layers at the interface between a nanoparticle and a nanowire. In the current investigation, the growth behavior in ternary InGaAs nanowires has been analyzed in situ, using environmental transmission electron microscopy. The investigation has revealed that multilayer growth also occurs for ternary nanowires and appears to be more common than in the binary case. In addition, the size of the multilayer stacks observed is much larger than what has been reported previously. The investigation details the implications of multilayers for the overall growth of the nanowires, as well as the surrounding conditions under which it has manifested. We show that multilayer growth is highly dynamic, where the stack of layers regularly changes size by transporting material between the growing layers. Another observation is that multilayer growth can be initiated in conjunction with the formation of crystallographic defects and compositional changes. In addition, the role that multilayers can have in behaviors such as growth failure and kinking, sometimes observed when creating heterostructures between GaAs and InAs ex situ, is discussed. The prevalence of multilayer growth in this ternary material system implies that, in order to fully understand and accurately predict the growth of nanowires of complex composition and structure, multilayer growth has to be considered.

Diameter Control of GaSb Nanowires Revealed by In Situ Environmental Transmission Electron Microscopy

“…The introduction of environmental transmission electron microscopes (ETEMs) has allowed the exploration of some of the previously hidden aspects of nanowire growth dynamics in real time. − Importantly, nanowires have in some circumstances been shown to exhibit unconventional growth modes that differ from the traditional view. , In situ growth has also proven to be an invaluable technique in developing new methods and strategies to circumvent known problems in conventional ex situ nanowire growth systems, which has most notably been demonstrated in Si nanowire growth. , The strength lies in that the surrounding growth conditions can be changed in real time based on the observations made, and the effects on the growth are immediate, which means that conclusions about the growth dynamics can quickly be drawn. By monitoring the growth and how it changes with the growth conditions, it is also easier to make rational decisions about how to adjust the growth conditions to achieve a specific result.…”

Direct Observation of Liquid–Solid Two‐Phase Seed Particle‐Assisted Kinking in GaP Nanowire Growth

“…After the seed particle was reshaped at the ZB GaP NW tip, multilayer growth (nucleation of new bilayers before the bilayer closest to the growth front could fully evolve) [ 64 ] promoted by the Cu 9 Ga 4 phase proceeded for approximately 10 GaP bilayers (see Movie S4, Supporting Information). Multilayer GaP NW growth via the VSS mechanism yielded a ZB GaP segment without the formation of twins/stacking faults ( Figure a).…”

Epitaxial growth of crystal phase quantum dots in III–V semiconductor nanowires

“…Layer by layer, generating the longitudinal growth of the NW. Although, multilayer growth has also been demonstrated 104 . After a certain growth time and for a chosen NW length, the growth conditions are changed to switch to crystal phase B.…”

“…It is worth mentioning that the layer evolution in ternary NWs can determine and affect the resulting composition 117 . Recently, Sjökvist and co-workers reported 104 , using in situ TEM investigations the growth of InGaAs NWs. Therefore, creating a stack of incomplete layers at the catalyst-NW interface.…”

“…However, multilayer growth has also been demonstrated. 103 After a certain growth time and for a chosen NW length, the growth conditions are changed to switch to crystal phase B. Note that the growth rate may change.…”