Janus two-dimensional materials based on group IV monochalcogenides

The discovery and design of two-dimensional (2D) materials has aided the development of novel nanoscale devices for various applications. Here, we show the structural, electronic, and vibrational properties of 15 2D materials based on Janus substitution (atomic layer substitution) of group IV monochalcogenides. Although group IV monochalcogenides have already been extensively studied because of their very promising piezoelectric and thermoelectric properties, these Janus materials appear as potential candidates for similar applications but with a broken symmetry that can enrich their electronic and optical properties and the coupling of these with other physical properties. Based on first-principles calculations, we investigate the stability of the Janus materials according to energetic, dynamical, and mechanical criteria. Understanding of the physical properties of these 2D materials can provide guidance for the development of novel nanoscale electronic devices.