Pb9Si8O22Cl6 and Pb3.07Ca1.93Si3O11: Two Ultraviolet Nonlinear Optical Materials Exhibit a Moderate Second Harmonic Generation Response

Finding novel efficient nonlinear optical materials with large second-order nonlinearity for the UV spectral range remains a formidable challenge, especially for silicate systems. Using a high-temperature solid reaction in a tight vacuum environment, two ultraviolet nonlinear optical materials with a moderate second harmonic generation (SHG) response have been created: Pb9Si8O22Cl6 and Pb3.07Ca1.93Si3O11. The SHG values they computed are roughly 2.4 and 3.5 times higher than those of KH2PO4 (KDP). This study reports on Pb9Si8O22Cl6 and Pb3.07Ca1.93Si3O11 syntheses, crystal structures, and optical characteristics. In addition, the relationship between electronic structure and optical properties was clarified by first-principles theoretical computations.