@phdthesis{Bettscheider2022,
  author    = {Bettscheider, Simon},
  title     = {Shape stability and bundling of ultrathin nanowires},
  organization    = {INM - Leibniz-Institut f{\"u}r Neue Materialien},
  doi       = {10.22028/D291-38167},
  institution = {Structure Formation},
  school    = {Universit{\"a}t des Saarlandes},
  year      = {2022},
  abstract  = {Ultrathin nanowires are promising nanoscale materials. They can reach length-to-diameter aspect ratios exceeding 1000, making them suitable building blocks for optoelectronic devices such as transparent conducting films. An organic ligand shell surrounds their inorganic core, provides colloidal stability, and guides their one-dimensional growth. Two unresolved issues limit their application. Nanowires can agglomerate into elongated bundles, but efficient use of this superstructure is difficult since we do not yet understand the bundling mechanisms. Furthermore, nanowires are prone to the Plateau-Rayleigh instability: thin wires tend to fragment into discrete spheroidal particles to reduce their surface energy, limiting their lifetime and reliability. This thesis investigates superstructure formation and nanowire stability and the link between both topics. Bundles are shown to emerge in non-polar solvents for entropic reasons. Solvent or unbound ligand molecules align in proximity to the ligand shell, thus losing entropy. Bundling decreases this loss in entropy by reducing contact with the bulk solvent. The structural stability of nanowires is enhanced or degraded by the ligand shell, depending on the relationship between free energy and local surface curvature. Kinetic barriers in ad- and desorbing ligands and rearrangement of surface atoms slow down the break-up. Bundling further stabilizes the wires by confining the space available to them.},
  language  = {en}
}