Lou Xiao-Yu, Jiang Xiao-Ming, Liu Bin-Wen, Guo Guo-Cong
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China.
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian, 350002, P. R. China.
Small. 2024 Jan;20(3):e2305711. doi: 10.1002/smll.202305711. Epub 2023 Sep 11.
The typical chalcopyrite AgGaQ (Q = S, Se) are commercial infrared (IR) second-order nonlinear optical (NLO) materials; however, they suffer from unexpected laser-induced damage thresholds (LIDTs) primairy due to their narrow band gaps. Herein, what sets this apart from previously reported chemical substitutions is the utilization of an unusual cationic substitution strategy, represented by [[SZn ]S + [S Zn ]S + 11ZnS ⇒ MS + [M Cl]S + 11GaS ], in which the covalent S Zn units in the diamond-like sphalerite ZnS are synergistically replaced by cationic M Cl units, resulting in two novel salt-inclusion sulfides, M[M Cl][Ga S ] (M = A/Ba, A = K, 1; Rb, 2). As expected, the introduction of mixed cations in the GaS anionic frameworks of 1 and 2 leads to wide band gaps (3.04 and 3.01 eV), which exceeds the value of AgGaS , facilitating the improvement of high LIDTs (9.4 and 10.3 × AgGaS @1.06 µm, respectively). Furthermore, compounds 1 and 2 exhibit moderate second-harmonic generation intensities (0.84 and 0.78 × AgGaS @2.9 µm, respectively), mainly originating from the orderly packing tetrahedral GaS units. Importantly, this study demonstrates the successful application of the cationic substitution strategy based on diamond-like structures to provide a feasible chemical design insight for constructing high-performance NLO materials.
典型的黄铜矿型AgGaQ（Q = S，Se）是商业红外（IR）二阶非线性光学（NLO）材料；然而，由于其窄带隙，它们的激光诱导损伤阈值（LIDT）较低。在此，与先前报道的化学取代不同的是，采用了一种不寻常的阳离子取代策略，以[[SZn ]S + [S Zn ]S + 11ZnS ⇒ MS + [M Cl]S + 11GaS ]表示，其中类金刚石闪锌矿ZnS中的共价S Zn单元被阳离子M Cl单元协同取代，从而得到两种新型的含盐硫化物，M[M Cl][Ga S ]（M = A/Ba，A = K，1；Rb，2）。正如预期的那样，在1和2的GaS阴离子骨架中引入混合阳离子导致宽带隙（3.04和3.01 eV），超过了AgGaS的值，有助于提高高激光诱导损伤阈值（分别为9.4和10.3×AgGaS @1.06 µm）。此外，化合物1和2表现出中等的二次谐波产生强度（分别为0.84和0.78×AgGaS @2.9 µm），主要源于有序堆积的四面体GaS单元。重要的是，这项研究证明了基于类金刚石结构的阳离子取代策略的成功应用，为构建高性能NLO材料提供了可行的化学设计思路。
