Chinese Academy of Sciences Recently, Chinese scientists reported a new class of two-dimensional (2D) third-order nonlinear optical (NLO) materials, called metallated graphynes. The new material, exhibits broadband (at both 532 and 1064 nm) saturable absorption NLO property and high laser damage threshold. Researchers prepared two free-standing mercurated graphyne nanosheets by applying an interface-assisted bottom-up method. The large-area nanosheets derived from the chemical growth have shown their layered molecular structural arrangement, controllable thickness and enhanced π-conjugation. The mercurated graphyne nanosheets are therefore having stable and outstanding broadband nonlinear saturable absorption properties. With the help of the absorption ability, the metallated graphynes are acting as saturable absorbers. And it has better pulse properties and Q-switched performances, especially comparing with traditional 2D materials (like graphene, black phosphorus).