Stability, Electronic Structures, and Thermoelectric Properties of 2D Janus LiZnX (X = N, P, As)

In the framework of density functional theory, we investigated the structure and mechanical properties of Janus monolayer LiZnX (X = N, P, As). The electronic and phonon transport preferences were calculated on the basis of the Boltzmann transport theory. We discovered that the band gaps of these three single-layers are 0.93–2.17 eV, and they are direct band semiconductors. Also, the monolayers exhibit relatively high electron and hole mobilities of ∼103 cm2·V–1·s–1 and ∼102 cm2·V–1·s–1, respectively. Besides, they possess the high Seebeck coefficient (0.16–1.99 mV·K–1), large conductivity (∼107 Ω–1·m–1), and low lattice thermal conductivity (0.52–3.59 W·m–1·K–1). Hence, all monolayers show high thermoelectric properties, with favorable ZT values of 0.36, 0.78, and 1.22 for p-type doping LiZnN, LiZnP, and LiZnAs at room temperature, even up to 0.48–4.16 at 500 K. In general, the monolayer LiZnX (X = N, P, As) are promising for applications in thermoelectric and microelectronic devices.