Syntheses, characterization and nonlinear optical properties of a bismuth subcarbonate Bi2O2CO3

A novel nonlinear optical (NLO) material Bi2O2CO3 has been successfully developed by the hydrothermal method. It was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, high resolution transmission electron microscopy (HRTEM), UV–vis–NIR diffuse reflectance spectrum (DRS) and photoluminescence (PL) spectra. The band gap was determined to be 3.42 eV, and the PL properties of Eu3+ doped Bi2O2CO3 under UV excitation have also been investigated. The powder second-harmonic generation (SHG) measurement performed on the ground crystal indicates that the NLO efficiency is approximately 5 times as large as that of KDP (KH2PO4) standard. In addition, the origin of large SHG for Bi2O2CO3 was also researched according to its crystal structure.