PbB5O7F3: A High-Performing Short-Wavelength Nonlinear Optical Material

Nonlinear optical materials are the vital components of future photonic technologies as they can transfer and process data at the speed of light. However, the necessary prerequisites for a practical nonlinear optical material are very strict, and it is still a huge challenge to achieve the perfect balance among three critical parameters for nonlinear optics, including short cutoff edges, strong second-harmonic generation responses, and a suitable birefringence. Herein, via the introduction of the lone pair Pb2+ cations with stereochemical activity and the F- anions with the largest electronegativity into borate, a new fluorooxoborate PbB5O7F3 was obtained successfully. It exhibits a short cutoff edge (similar to 225 nm), a strong second-harmonic generation response (approximately 6 x KDP@1064 nm), and a large birefringence (cal. 0.12@1064 nm), achieving the optimal balance among the three critical parameters mentioned above for nonlinear optical applications in the short-wavelength region. The first-principles calculations were carried out to investigate the structure-property relationship of PbB5O7F3.