Halonitrides Zn<sub>2</sub>NX (X=Cl,Br): Novel Mid-Infrared Nonlinear Optical Materials
Xin Zhao, Chensheng Lin, Jindong Chen, Min Luo, Feng Xu, Shunda Yang, Shuangshuang Shi, Bingxuan Li, Ning Ye
Abstract
Continuously, nitrides are mainly regarded as semiconductors or thermal conductivity materials and applied in photonic devices. In this work, we proposed that nitrides may also be a new system for mid-infrared (mid-IR) nonlinear optical (NLO) materials. Meanwhile, we first report the halonitrides Zn2NX (X = Cl, Br) as mid-IR NLO crystals, which were synthesized by a solid–liquid reaction. Both compounds show excellent optical properties including large band gaps (3.21 and 3.28 eV), strong second-harmonic generation responses (0.9 and 0.8 × AGS), a wide IR transparent range (0.37–8.0 μm for Zn2NBr) and moderate birefringences (Δn = 0.060 and 0.063). Also, the powder laser damage threshold (LDT) measurements revealed that they had high LDTs (20.7 and 25.9 × AGS). This study suggests that not only nitrides may be potential and outstanding mid-IR NLO candidates but also the combination of different anions into one structure will be a feasible strategy to discover high-performance NLO materials.