First-Principles Study on Lithium Intercalation in Traditional Semiconductors Leading to Investigation of Structural Stability and Thermoelectric Properties of Their 2D Structures

In this study, we systematically investigated the lithium intercalation into nearly 30 traditional wurtzite phase semiconducting group II–VI, III–V, and IV–IV compounds. As a result, the compounds formed different structural types of layers, i.e., monolayer, bilayer, ladder-type, ribbon-type, and unexfoliated type. In addition, we correlated the reaction’s progress using each of their bulk Pauling ionic radii. After that, 20 exfoliated layers of compounds were studied. As an outcome of these calculations, they can be classified into three distinct 2D layers, which are monolayer (ML), double layer honeycomb (DLHC), and double layer square lattice (DLSL). By using the first-principles calculations to study the structural, mechanical, dynamical, electronic, and thermoelectric properties of 20 2D layers in order to determine their distinctive characteristics, our results show that most of these 2D layers are dynamically and mechanically stable. Electronic properties show that ML and DLHS structures exhibit a semiconducting nature, while the DLSL structure shows a high conducting nature. Finally, the thermoelectric behavior reveals that 20 2D layers possess outstanding figures of merit (ZT) in the range of 0.5–1.0 at 300 K, thereby they can be used as thermoelectric applications.