Real-Time Observation of Morphological Transformations in II-VI Semiconducting Nanobelts via Environmental Transmission Electron Microscopy.
It has been observed that wurtzite II-VI semiconducting nanobelts transform into single-crystal, periodically branched nanostructures upon heating. The mechanism of this novel transformation has been elucidated by heating II-VI nanobelts in an environmental transmission electron microscope (ETEM) in oxidizing, reducing, and inert atmospheres while observing their structural changes with high spatial resolution. The interplay of surface reconstruction of high-energy surfaces of the wurtzite phase and environment-dependent anisotropic chemical etching of certain crystal surfaces in the branching mechanism of nanobelts has been observed. Understanding of structural and chemical transformations of materials via in situ microscopy techniques and their role in designing new nanostructured materials is discussed.
†Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Rahul
R
Agarwal
‡Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States.
Dmitri N
DN
Zakharov
†Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Nadia M
NM
Krook
†Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Wenjing
W
Liu
†Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Jacob S
JS
Berger
‡Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States.
Eric A
EA
Stach
†Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Ritesh
R
Agarwal
D016880:Anisotropy; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology; D012666:Semiconductors; D013499:Surface Properties
Branched nanostructure; environmental TEM; heterostructure; in situ TEM; nanobelt