Defects and strain enhancements of second-harmonic generation in Si/Ge superlattices

Matteo Bertocchi (1) , E. Luppi (2) , Elena Degoli (3) , Valérie Véniard (4, 5) , Stefano Ossicini (1, 6)

1 Dipartimento di Scienze e Metodi dell'Ingegneria
2 LCT - Laboratoire de chimie théorique
3 Istituto di Nanoscienze
4 LSI - Laboratoire des Solides Irradiés
5 ETSF - European Theoretical Spectroscopy Facility
6 Centro Interdipartimentale En&Tech

Starting from experimental findings and interface growth problems in Si/Ge superlattices, we have investigated through ab initio methods the concurrent and competitive behavior of strain and defects in the second-harmonic generation process. Interpreting the second-harmonic intensities as a function of the different nature and percentage of defects together with the strain induced at the interface between Si and Ge, we found a way to tune and enhance the second-harmonic generation response of these systems. (C) 2014 AIP Publishing LLC.

Domains: Engineering Sciences [physics]; Mechanics [physics.med-ph]

Matteo Bertocchi, E. Luppi, Elena Degoli, Valérie Véniard, Stefano Ossicini. Defects and strain enhancements of second-harmonic generation in Si/Ge superlattices. Journal of Chemical Physics, 2014, 140 (21), pp.214705. ⟨10.1063/1.4880756⟩. ⟨hal-01024364⟩