CsBP2O6(OH)2: A Second-Order NLO Material with Unique Borophosphate Anionic Partial Structure and Strong SHG Effect

A noncentrosymmetric (NCS) alkali-metal borophosphate CsBP2O6(OH)2 (CBPO) containing unique borophosphate anionic partial structure has been obtained through a mixed-solvent thermal method. Its structure could be regarded as a 1-D chain that is built by Cs+ cations and unique anionic chain [BP2O6(OH)2]∞n- composed of BO4 and PO3(OH) groups. CBPO possesses a wide UV-vis transparent range and the strong SHG response. Moreover, we have well explored and established the origin of SHG effect by the dipole moment and PDOS calculations. This work will help inspire and stimulate scientists to discover more excellent NLO materials.