title: Outstanding laser damage threshold in Li2MnGeS4 and tunable optical nonlinearity in diamond-like semiconductors.
abstract: The new Li2MnGeS4 and Li2CoSnS4 compounds result from employing a rational and simple design strategy that guides the discovery of diamond-like semiconductors (DLSs) with wide regions of optical transparency, high laser damage threshold, and efficient second-order optical nonlinearity. Single-crystal X-ray diffraction was used to solve and refine the crystal structures of Li2MnGeS4 and Li2CoSnS4, which crystallize in the noncentrosymmetric space groups Pna21 and Pn, respectively. Synchrotron X-ray powder diffraction (SXRPD) was used to assess the phase purity, and diffuse reflectance UV-vis-NIR spectroscopy was used to estimate the bandgaps of Li2MnGeS4 (Eg = 3.069(3) eV) and Li2CoSnS4 (Eg = 2.421(3) eV). In comparison with Li2FeGeS4, Li2FeSnS4, and Li2CoSnS4 DLSs, Li2MnGeS4 exhibits the widest region of optical transparency (0.60-25 μm) and phase matchability (≥1.6 μm). All four of the DLSs exhibit second-harmonic generation and are compared with the benchmark NLO material, AgGaSe2. Most remarkably, Li2MnGeS4 does not undergo two- or three-photon absorption upon exposure to a fundamental Nd:YAG beam (λ = 1.064 μm) and exhibits a laser damage threshold > 16 GW/cm(2).
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University , Pittsburgh, Pennsylvania 15282, United States.
authors.forename: Jacilynn A
authors.initials: JA
authors.lastname: Brant
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Clark
authors.forename: Yong Soo
authors.initials: YS
authors.lastname: Kim
authors.forename: Joon I
authors.initials: JI
authors.lastname: Jang
authors.forename: Ashley
authors.initials: A
authors.lastname: Weiland
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Aitken
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005857:Germanium / Q000737:chemistry*; D007834:Lasers; D018020:Lithium Compounds / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D017711:Nonlinear Dynamics; D055620:Optical Phenomena; D012666:Semiconductors
chemical_list: D056831:Coordination Complexes; D018020:Lithium Compounds; D005857:Germanium