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Title: Realization of highly crystallographic three-dimensional nanosheets by a stress-induced oriented-diffusion method

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4892091· OSTI ID:22311365
; ; ;  [1];  [2]
  1. Thin Film and Nanoelectronics Lab, Nanoelectronics Center of Excellence, School of Electrical and Computer Engineering, University of Tehran, Tehran 143957131 (Iran, Islamic Republic of)
  2. Nano-Physics Research Lab, Department of Physics, University of Tehran, Tehran 1439955961 (Iran, Islamic Republic of)

Morphologically controlled nanostructures have been increasingly important because of their strongly shape dependent physical and chemical properties. Formation of nanoscale silicon based structures that employ high levels of strain, intentional, and unintentional twins or grain boundaries can be dramatically different from the commonly conceived bulk processes. We report, realization of highly crystallographic 3D nanosheets with unique morphology and ultra-thin thickness by a stress-induced oriented-diffusion method, based on plasma processing of metal layer deposited on Si substrate and its post deep reactive ion etching. Annealing in plasma ambient creates rod-like metal alloy precursors which induce stress at its interface with Si substrate due to the mismatch of lattice constants. This stress opens facilitated gateways for orientated-diffusion of metal atoms in 〈110〉 directions and leads to formation of NSs (nanosheets) with [111] crystalline essence. Nanosheets are mainly triangular, hexagonal, or pseudo hexagonal in shape and their thicknesses are well controlled from several to tens of nanometers. The structural and morphological evolution of features were investigated in detail using transmission electron microscope, atomic force microscope, scanning electron microscope and possible mechanism is proposed to explain the formation of the thermodynamically unfavorable morphology of nanosheets. Significant photoemission capability of NSs was also demonstrated by photoluminescence spectroscopy.

OSTI ID:
22311365
Journal Information:
Applied Physics Letters, Vol. 105, Issue 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English