NaGa₃Se₅: An Infrared Nonlinear Optical Material with Balanced Performance Contributed by Complex {[Ga₃Se₅]⁻}_∞ Anionic Network

Abstract

Second-order nonlinear optical (NLO) materials are extensively applied in laser-related techniques. For developing IR NLO materials, chalcogenides are the main candidates. Here, NaGa 3 Se 5 was explored as inspired by its unique anionic structure. It crystallizes with the orthorhombic chiral P2 1 2 1 2 1 structure, featuring 12 types of GaSe 4 tetrahedra built into a three-dimensional {[Ga 3 Se 5 ] − } ∞ anionic network, representing a new NLO-functional motif. NaGa 3 Se 5 exhibits large and phase-matchable NLO response 1.37 × AgGaS 2 . It has the largest band gap among the noncentrosymmetric A−M III −Se (A = alkali metal; M = Ga, In) compounds. The NLO properties' origin is explored via theoretical analysis. The success of NaGa 3 Se 5 contributes a practical case for exploring new NLO materials.

Ba3.5Cu7.55In1.15Se9: A Wide-Bandgap Copper Indium Selenide Reveals Strong Luminescence and Third-Harmonic Generation

“…The performance of photoluminescence is crucial to revealing the potential of photovoltaic (PV) materials, as the high conversion efficiency of photoexcited electrons into photons implies a reduced loss from nonradiative decay, thereby minimizing the discrepancy between the open-circuit voltage and the band gap. , For the wide band gap of organic–inorganic halide perovskite (1.6–2.3 eV), the solid solutions have been tuned to reach a 30% quantum yield of photoluminescence . In addition, metal chalcogenides are nonlinear optical materials used in the infrared optical range, where polarized tetrahedra are confined in a two-dimensional layered topology that is expected to generate stronger nonlinear optical responses and larger birefringences to facilitate phase matching. − The high polarizability of the crystal structure could yield a large THG response that does not even cancel out in the centrosymmetric environment. − Here, the tuned equilibrium composition synthesis, crystal structure, in situ thermal analysis by synchrotron powder X-ray diffraction, photoluminescence, Hall effect, and third-harmonic generation will be characterized for the novel copper indium selenide Ba 3.5 Cu 7.55 In 1.15 Se 9 .…”

Polysubstitution Induced Centrosymmetric-to-Noncentrosymmetric Structural Transformation and Nonlinear-Optical Behavior: The Case of Na0.45Ag0.55Ga3Se5

“…19−22 Among the potential chalcogenides, the A-M-Q (A = alkali or alkaline-earth metal; M = tetra-coordinated metal; Q = chalcogen) system is an attractive class of compounds with rich chemical compositions and structures. For the A-M 3 -Q 5 or A-Ag-M 6 -Q 10 (A = alkali metal; M = Ga, In; Q = S, Se, Te) subsystem members (Table S1), some promising IR NLO candidates have been studied, including NaGa 3 Se 5 , 23 Na 2 Ga x In 6−x Se 10 (x = 3 and 3.76), 24 AAgGa 6 S 10 (A = K, Rb, Cs), 25 NaGaIn 2 Se 5 , 26 and CsAgGa 6 S 10 . 27 Examples with cations independently occupying the A site in this family have been extensively reported, while cases with cations cooccupying the A site have never been studied.…”