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Title: Molecular Dynamics Study of High Symmetry Planar Defect Evolution during Growth of CdTe/CdS Films

The growth dynamics and evolution of intrinsic stacking faults, lamellar, and double positioning twin grain boundaries were explored using molecular dynamics simulations during the growth of CdTe homoepitaxy and CdTe/CdS heteroepitaxy. Initial substrate structures were created containing either stacking fault or one type of twin grain boundary, and films were subsequently deposited to study the evolution of the underlying defect. Results show that during homoepitaxy the film growth was epitaxial and the substrate’s defects propagated into the epilayer, except for the stacking fault case where the defect disappeared after the film thickness increased. In contrast, films grown on heteroepitaxy conditions formed misfit dislocations and grew with a small angle tilt (within ~5°) of the underlying substrate’s orientation to alleviate the lattice mismatch. Grain boundary proliferation was observed in the lamellar and double positioning twin cases. Finally, our study indicates that it is possible to influence the propagation of high symmetry planar defects by selecting a suitable substrate defect configuration, thereby controlling the film defect morphology.
Authors:
ORCiD logo [1] ;  [1] ;  [2] ;  [2] ;  [2]
  1. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
  2. Univ. of Texas at El Paso, El Paso, TX (United States)
Publication Date:
Report Number(s):
SAND-2017-10411J
Journal ID: ISSN 1932-7447; 657306
Grant/Contract Number:
AC04-94AL85000; EE0005958
Type:
Published Article
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 122; Journal Issue: 1; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; thin films; cadmium compounds; CdTe; dislocations; grain boundaries; stacking fault; lamellar twin; double positioning twin
OSTI Identifier:
1415335
Alternate Identifier(s):
OSTI ID: 1421857