Se₂(B₂O₇):  A New Type of Second-Order NLO Material

Exploration on the compounds in the selenite−borate system led to the discovery of a new second-order NLO material, Se₂B₂O₇, with a SHG efficiency of about 2.2 times that of KDP (KH₂PO₄). Its structure features a 3D network with helical tunnels, and it is transparent in the UV and visible region. The compound is a wide band gap semiconductor.