Quaternary diamond-like sulfides for nonlinear optical applications: Investigation into composition-structure-property relationships of the I2-II-IV-VI4 and I4-II-IV2-VI7 formulae

Author

Jordan KellyFollow

Defense Date

2-9-2024

Graduation Date

Spring 5-10-2024

Availability

One-year Embargo

Submission Type

dissertation

Degree Name

PhD

Department

Chemistry and Biochemistry

School

School of Science and Engineering

Committee Chair

Jennifer Aitken

Committee Member

Thomas Montgomery

Committee Member

Paul Lummis

Committee Member

Alexander Kendall

Keywords

Inorganic Chemistry, Diamond-Like Semiconductor, Nonlinear Optics, X-ray Diffraction, Electronic Structure, Crystal Structure

Abstract

The research work presented in this dissertation focuses on the synthesis, characterization, and property assessment of new and existing quaternary diamond-like semiconductor (DLS) materials for the potential application in infrared (IR) nonlinear optics (NLO). Chapter 2 discusses the previously discovered temperature-dependent polymorphs of Cu₂ZnGeS₄ (CZGS); however, the IR NLO properties, neutron powder diffraction data, and single crystal X-ray diffraction structures were previously undetermined. The high-temperature α-CZGS polymorph was superior to the low-temperature β-CZGS analog in both second harmonic generation (SHG) and laser-induced damage threshold (LIDT). Chapter 3 presents the discovery of Li₂MgGeS₄ and comparison to the Cu₂MgGeS₄ analog that previously was not assessed using wavelength-dependent SHG or LIDT measurements. Li₂MgGeS₄ was evaluated to have one of the highest, if not the highest, LIDT of known quaternary DLS with an SHG response not as impressive but still significant. In comparison, Cu₂MgGeS₄ had a comparable LIDT to AGS and a lackluster SHG that exponentially diminished with an increasing input wavelength. Chapter 4 reports on the discovery of Cu₄ZnGe₂S₇ and Cu₄CdGe₂S₇ that was published in the Journal of Alloys and Compounds. The single crystal X-ray diffraction structures of both compounds are reported and analyzed, along with electronic structure calculations, optical bandgaps, and NLO properties. Cu₄ZnGe₂S₇ was found to have a phase-matching SHG response but a low LIDT, while the SHG response for Cu₄CdGe₂S₇ was considerably weak, but the compound did have a larger LIDT. Overall, the research shows the potential of Li₂MgGeS₄ in high-powered laser applications and α-CZGS and Cu₄ZnGe₂S₇ for low-powered purposes.

Language

English

Recommended Citation

Kelly, J. (2024). Quaternary diamond-like sulfides for nonlinear optical applications: Investigation into composition-structure-property relationships of the I2-II-IV-VI4 and I4-II-IV2-VI7 formulae (Doctoral dissertation, Duquesne University). Retrieved from https://dsc.duq.edu/etd/2341

Additional Citations

Kelly, J. C.; Hoyer, C. E.; Shin, S. H.; Cho, J. B.; Stoyko, S. S.; Bonnoni, A.; Craig, A. J.; Rosello, K. E.; O’Hara, E. T.; Jang, J. I.; Aitken, J. A., Crystal structure, electronic structure, and optical properties of Cu4ZnGe2S7 and Cu4CdGe2S7: Polar diamond-like semiconductors exhibiting second harmonic generation. J. Alloys Compd. 2024, 970, 172437. https://doi.org/10.1016/j.jallcom.2023.172437