Since the first isolation of single graphene layer from bulk graphite via Scotch tape, various other layered two-dimensional (2D) materials, including hexagonal boron nitride and transition metal dichalcogenides like MoS2 and WS2, were isolated through a similar method. Although the bulk form of these materials had been well studied for decades, the atomically thin 2D layers attracted new interest due to the new electronic, chemical, and optical characteristics compared with their bulk counterparts. The synthesis of phosphorene, a monolayer form of bulk black phosphorus, is another attempt in the exploration of post-graphene 2D materials.