Anisotropic PC6N Monolayer with Wide Band Gap and Ultrahigh Carrier Mobility

The discovery of two-dimensional (2D) materials with direction-control behavior, wide band gap, and high carrier mobility is highly desirable for the development of advanced optoelectronic devices with photoresponse in the blue and ultraviolet range. Here, we predict an ideal optoelectronic material, a buckled graphene-like PC6N, which not only shows a direct wide band gap of 2.56 eV and anisotropic high hole mobility (104 cm2 V–1 s–1) but is also transparent to visible light and has a high absorption coefficient (105 cm–1) in the ultraviolet region. In this way, PC6N presents both a wide band gap and high mobility, a long-pursued target in the 2D semiconducting field. Lone electron pairs, originated from N and P atoms, disconnect delocalized π electrons of C6 rings, making the material a semiconductor. Its anisotropic charge transport can be attributed to the direction-dependent atomic arrangement. PC6N shows a high melting point, good dynamical stability, and oxidation resistance to air. These interesti...