Cd₅As₂Br₄: A TernaryArsenide with Nonlinear Optical Property

In this research, a new ternary arsenide, Cd₅As₂Br₄, with a nonlinear optical (NLO) property has been synthesized. Cd₅As₂Br₄ possesses a noncentrosymmetric structure with a space group belonging to the orthorhombic crystal system, specifically <i>Pna</i>2₁. The structure of Cd₅As₂Br₄ is formed by the interconnection of three one-dimensional structures, resulting in a three-dimensional structure. The diffuse reflectance spectrum reveals that Cd₅As₂Br₄ has a direct band gap of 1.91 eV. NLO performance tests indicate that at a particle size range of 20–50 μm, the second harmonic generation (SHG) intensity of Cd₅As₂Br₄ is 0.7 times that of AgGaS₂ (AGS), and it exhibits nonphase-matching behavior at 2090 nm. Additionally, at a particle size range of 125–150 μm, the laser-induced damage threshold (LIDT) of Cd₅As₂Br₄ is equal to that of AGS. Finally, theoretical calculations elucidate that Cd₅As₂Br₄ possesses a calculated maximum SHG coefficient <i>d</i>₁₅ of −11.66 pm/V.