@inproceedings{fc63c510d4764675b33ccb7879ae828f,
title = "Terahertz emission from 2D nanomaterials",
abstract = "Group-IV monochalcogenides belong to a family of 2D layered materials. Monolayers of group-IV monochalcogenides GeS, GeSe, SnS and SnSe have been theoretically predicted to exhibit a large shift current owing to a spontaneous electric polarization at room temperature. Using THz emission spectroscopy, we find that above band gap photoexcitation with ultrashort laser pulses results in emission of nearly single-cycle THz pulses due to a surface shift current in multi-layer, sub-μm to few-μm thick GeS and GeSe, as inversion symmetry breaking at the crystal surface enables THz emission by the shift current. Experimental demonstration of THz emission by the surface shift current puts this layered group-IV monochalcogenides forward as a candidate for next generation shift current photovoltaics, nonlinear photonic devices and THz sources.",
keywords = "2D materials, GeS, GeSe, Terahertz emission spectroscopy, shift current, terahertz generation",
author = "Kateryna Kushnir and Mengjing Wang and Ying Qin and Guangjiang Li and Sefaattin Tongay and Koski, {Kristie J.} and Titova, {Lyubov V.}",
note = "Funding Information: We acknowledges support from the NSF DMR-1750944, and thank Benjamin Fregoso for insightful discussions. Publisher Copyright: {\textcopyright} 2018 SPIE.; Terahertz Emitters, Receivers, and Applications IX 2018 ; Conference date: 19-08-2018 Through 20-08-2018",
year = "2018",
doi = "10.1117/12.2322160",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Manijeh Razeghi and Baranov, {Alexei N.}",
booktitle = "Terahertz Emitters, Receivers, and Applications IX",
}