Limitations to the realization of noncentrosymmetric SimGen superlattices

Download
  1. Get@NRC: Limitations to the realization of noncentrosymmetric SimGen superlattices (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1103/PhysRevB.50.8564
AuthorSearch for: ; Search for: ; Search for:
TypeArticle
Journal titlePhysical review. B, Condensed matter and materials physics
Volume50
Issue12
Pages85648568; # of pages: 5
AbstractWe extend the work of Bottomley et al. [Appl. Phys. Lett. 63, 2324 (1993)] on second-harmonic generation from short-period (SimGen)p strained-layer superlattices (SLS) with n and m both odd integers. Such structures are theoretically predicted to be noncentrosymmetric and therefore should possess a large bulk, nonlinear susceptibility ?(2). However, the prior work showed that the inevitable presence of single atomic-height steps on the Si(001) substrate leads to the formation of antiphased domains within the SLS and hence a macroscopically centrosymmetric material. Here we report second-harmonic generation induced by a 775-nm beam on several samples of nominally (Si7Ge3)20 SLS?s grown on several substrates vicinal to Si(001), including those with biatomic-height steps; the latter substrates should allow in-phase domains to be grown. A nonzero, but weak bulk ?(2) is obtained. We propose that the weak nonlinear response is influenced by nonideal superlattice periodicity which results in the formation of antiphase domains along the growth direction. Suggestions are offered for how noncentrosymmetric SLS?s may eventually be realized.
Publication date
AffiliationNational Research Council Canada; NRC Institute for Microstructural Sciences
Peer reviewedNo
NPARC number12328270
Export citationExport as RIS
Report a correctionReport a correction
Record identifierff75af4c-986f-4dbe-a216-4a3dcbb5c913
Record created2009-09-10
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)