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arXiv · 1707.00200

Strong second harmonic generation in two-dimensional ferroelectric IV-monochalcogenides

Suman Raj Panday·Benjamin M. Fregoso
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Abstract

The two-dimensional ferroelectrics GeS, GeSe, SnS and SnSe are expected to have large spontaneous in-plane electric polarization and enhanced shift-current response. Using density functional methods, we show that these materials also exhibit the largest effective second harmonic generation reported so far. It can reach magnitudes up to $10$ nm/V which is about an order of magnitude larger than that of prototypical GaAs. To rationalize this result we model the optical response with a simple one-dimensional two-band model along the spontaneous polarization direction. Within this model the second-harmonic generation tensor is proportional to the shift-current response tensor. The large shift current and second harmonic responses of GeS, GeSe, SnS and SnSe make them promising non-linear materials for optoelectronic applications.

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Suman Raj Panday, Benjamin M. Fregoso. 2017-09-29. Strong second harmonic generation in two-dimensional ferroelectric IV-monochalcogenides. https://doi.org/10.1088/1361-648x%2Faa8bfc

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