Direct
Observation of Transient Surface Species during
Ge Nanowire Growth and Their Influence on Growth Stability
Saujan
V. Sivaram
Naechul Shin
Li-Wei Chou
Michael A. Filler
10.1021/jacs.5b03818.s001
https://acs.figshare.com/articles/journal_contribution/Direct_Observation_of_Transient_Surface_Species_during_Ge_Nanowire_Growth_and_Their_Influence_on_Growth_Stability/2141395
Surface
adsorbates are well-established choreographers of material
synthesis, but the presence and impact of these short-lived species
on semiconductor nanowire growth are largely unknown. Here, we use
infrared spectroscopy to directly observe surface adsorbates, hydrogen
atoms and methyl groups, chemisorbed to the nanowire sidewall and
show they are essential for the stable growth of Ge nanowires via
the vapor–liquid–solid mechanism. We quantitatively
determine the surface coverage of hydrogen atoms during nanowire growth
by comparing ν(Ge–H) absorption bands from <i>operando</i> measurements (i.e., during growth) to those after saturating the
nanowire sidewall with hydrogen atoms. This method provides sub-monolayer
chemical information at relevant reaction conditions while accounting
for the heterogeneity of sidewall surface sites and their evolution
during elongation. Our findings demonstrate that changes to surface
bonding are critical to understand Ge nanowire synthesis and provide
new guidelines for rationally selecting catalysts, forming heterostructures,
and controlling dopant profiles.
2015-08-12 00:00:00
hydrogen atoms
Ge Nanowire Growth
Ge nanowire synthesis
semiconductor nanowire growth
sidewall surface sites
Transient Surface Species
nanowire sidewall
Growth StabilitySurface adsorbates