A potassium lead 2-methylmalonate-iodide nonlinear optical crystal with strong second-harmonic generation response and large birefringence

• Published in: Scripta materialia Vol. 239; p. 115824
• Main Authors: Li, Shuang-Cheng, Geng, Zi-Long, Fu, Rui-Biao, Ma, Zu-Ju, Wu, Xin-Tao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2024
• Subjects: Birefringence; Iodide; Lead; Nonlinear optical crystal; Second-harmonic generation; Lead; Iodide; Birefringence; Second-harmonic generation; Nonlinear optical crystal
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/j.scriptamat.2023.115824

Nonlinear optical (NLO) crystals play a significant role in optoelectronic industry. Herein, a new NLO crystal, K(H2O)[KI][PbI(C4H4O4)], has been rationally obtained by tuning halide perovskite materials with 2-methylmalonate group. K(H2O)[KI][PbI(C4H4O4)] features that the highly distorted [PbO4I2] polyhedron with large hyperpolarizability and prominent polarizability anisotropy is served as a bifuntional unit. Remarkably, the distorted [PbO4I2] polyhedrons are aligned in an oriented arrangement that leads to the effective superposition of their microscopic second-order nonlinear susceptibilities and the enhancement of optical anisotropy. Notably, K(H2O)[KI][PbI(C4H4O4)] exhibits a strong phase-matching SHG response of 5.6 × KDP and a large birefringence (Δnobv. = 0.24@546 nm). Theoretical calculations elucidate that the strong SHG response and the large birefringence are predominantly attributed to the directional arrangement of the highly distorted [PbO4I2] polyhedrons. Our discovery provides an effective path for the rational exploration of high-performance NLO crystals. A new nonlinear optical crystal, K(H2O)[KI][PbI(C4H4O4)], has been rationally obtained. K(H2O)[KI][PbI(C4H4O4)] features that the distorted [PbO4I2] polyhedrons are aligned in an oriented arrangement, leading to the effective superposition of their microscopic second-order nonlinear susceptibilities and the enhancement of optical anisotropy. Remarkably, K(H2O)[KI][PbI(C4H4O4)] exhibits a strong phase-matching SHG response of 5.6 × KDP and a large birefringence (Δnobv. = 0.24@546 nm). [Display omitted]