Structural, Optical, and Electronic Properties of Two Quaternary Chalcogenide Semiconductors: Ag2 SrSiS4 and Ag2 SrGeS4 .

Journal Article (Journal Article)

Quaternary chalcogenide materials have long been a source of semiconductors for optoelectronic applications. Recent studies on I2 -II-IV-X4 (I = Ag, Cu, Li; II = Ba, Sr, Eu, Pb; IV = Si, Ge, Sn; X = S, Se) materials have shown particular versatility and promise among these compounds. These semiconductors take advantage of a diverse bonding scheme and chemical differences among cations to target a degree of antisite defect resistance. Within this set of compounds, the materials containing both Ag and Sr have not been experimentally studied and leave a gap in the full understanding of the family. Here, we have synthesized powders and single crystals of two Ag- and Sr-containing compounds, Ag2 SrSiS4 and Ag2 SrGeS4 , each found to form in the tetragonal I 4̅2m structure of Ag2 BaGeS4 . During the synthesis targeting the title compounds, two additional materials, Ag2 Sr3 Si2 S8 and Ag2 Sr3 Ge2 S8 , have also been identified. These cubic compounds represent impurity phases during the synthesis of Ag2 SrSiS4 and Ag2 SrGeS4 . We show through hybrid density functional theory calculations that Ag2 SrSiS4 and Ag2 SrGeS4 have highly dispersive band-edge states and indirect band gaps, experimentally measured as 2.08(1) and 1.73(2) eV, respectively. Second-harmonic generation measurements on Ag2 SrSiS4 and Ag2 SrGeS4 powders show frequency-doubling capabilities in the near-infrared range.

Full Text

Duke Authors

Cited Authors

  • McKeown Wessler, GC; Wang, T; Sun, J-P; Liao, Y; Fischer, MC; Blum, V; Mitzi, DB

Published Date

  • August 2021

Published In

Volume / Issue

  • 60 / 16

Start / End Page

  • 12206 - 12217

PubMed ID

  • 34319109

Electronic International Standard Serial Number (EISSN)

  • 1520-510X

International Standard Serial Number (ISSN)

  • 0020-1669

Digital Object Identifier (DOI)

  • 10.1021/acs.inorgchem.1c01416

Language

  • eng