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Nonlinear Optical Properties of 0D Chiral Hybrid Bismuth Iodides
Author(s) -
Chaturvedi Aman,
Rajput Parikshit Kumar,
Maqbool Shabnum,
Nag Angshuman,
Mandal Pankaj
Publication year - 2025
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202501022
Abstract Chiral hybrid metal halides show great promise for nonlinear optical (NLO) applications like circularly polarized second harmonic generation (SHG). The inherent toxicity of lead is a concern for the widespread adoption of frequently explored lead‐based chiral hybrid halides. Here, we report the second and third‐order NLO properties of lead‐free 0D chiral compounds, ( R ‐/ S ‐MBA) 4 Bi 2 I 10 , and their achiral counterpart, ( R ac‐MBA) 4 Bi 2 I 10 (MBA: methylbenzylammonium) under excitation wavelength ranging 1360–1590 nm. Chiral ( R ‐/ S ‐MBA) 4 Bi 2 I 10 exhibits strong SHG along with stronger third harmonic generation (THG). The chiral crystals showed high sensitivity to the handedness of circularly polarized pump light ( g SHG − CD ≈ 9% at 1510 nm). The THG response shows resonance enhancement matching the excitonic absorption. Achiral ( R ac‐MBA) 4 Bi 2 I 10 exhibits the maximum THG response (χ (3) = 1.05 × 10⁻¹⁸ m 2 V − 2 ) . Z‐scan measurements with non‐resonant femtosecond pulse excitation at 800 nm yield high nonlinear absorption coefficients (β) and nonlinear refractive index (n 2 ) for all three samples, with ( R ac‐MBA) 4 Bi 2 I 10 exhibiting the highest values. These hybrid chiral metal halides, with efficient second and third‐order nonlinearity, and high optical stability, are potential candidates for NLO applications such as Kerr‐based optical switching, circularly polarized up‐conversion, and communication.