Cd5As2Br4: A Ternary Arsenide 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 Pna21. 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 d15 of −11.66 pm/V.