Growth and Characterization of a Nonlinear Optical Crystal Cd3Te2WO10 Decorated by WO4 Tetrahedra Showing a Large Band Gap

A noncentrosymmetric nonlinear optical (NLO) crystal Cd3Te2WO10 with a large band gap has been synthesized and grown using the high-temperature solution method with TeO2 as a flux. Cd3Te2WO10, crystallized in P21, contains two classes of d0 W6+ and lone-pair Te4+ cations holding asymmetric coordination environments which are associated with the second-order Jahn–Teller effect. Importantly, it has a large band gap of 4.28 eV, which is profitable for high-power application, and wide transparency region of 0.29–5.63 μm, especially in 1–5 μm possessing tremendous transmittance that exceeded 80% and fully covering the 3–5 μm range, which is one of the vital atmospheric windows, and a good Raman performance that arises from the WO4 polyhedra. In addition, Cd3Te2WO10 features phase-matching behavior owing to large birefringence and considerable second-harmonic generation response equivalent to 1.1 times that of KH2PO4, which is further elucidated by the theoretical calculation. Therefore, our experimental results demonstrate that Cd3Te2WO10 could be used as a promising functional NLO crystal.