Featured with high thermal decomposition temperature and layered structure, violet phosphorus (VP) offers an unparalleled stable allotrope of phosphorus to demonstrate the optoelectronic device and photonics elements with high performance at the nanoscale. Here, we report few-layer and hundreds of nanometer-sized VP with robust stability in different solvents and ambient conditions by ultrasound-assisted liquid phase exfoliation approach. For the first time, the ultrafast carrier dynamics and third-order nonlinear optical response of VP were investigated. Sub-picosecond timescale ultrafast carrier dynamic and ultrafast nonlinear saturable absorption of VP were demonstrated. Our findings demonstrated that VP possessed a promising potential for use in ultrafast nonlinear photonic applications such as saturable absorbers and optical switches.

An emerging subclass of transition-metal dichalcogenides (TMDs), noble-transition-metal dichalcogenides (NMDs), has led to an increase in nanoscientific research in two-dimensional (2D) materials. NMDs feature a unique structure and several useful properties. 2D NMDs are promising candidates for a broad range of applications in areas such as photodetectors, phototransistors, saturable absorbers, and meta optics. In this review, the state of the art of 2D NMDs research, their structures, properties, synthesis, and potential applications are discussed, and a perspective of expected future developments is provided.