Unveiling the phonon scattering limited intrinsic carrier mobility and electronic, mechanical, and piezoelectric properties of novel Janus CrBZS 2 (Z = N, P, As) monolayers

Abstract In this work, we propose a series of novel two-dimensional (2D) Janus CrBZS 2 (Z = N, P, As) monolayers and systematically investigate their physical properties, including structural characteristics, mechanical behavior, piezoelectric (PIE) responses, electronic properties, and transport characteristics, using density functional theory calculations. Stability analyses indicate that these 2D materials possess robust crystal structures and are potentially synthesizable using conventional experimental methods. In their ground state, the CrBZS 2 monolayers are semiconductors with moderate band gaps. Zeeman-type spin splitting is observed when spin–orbit coupling is taken into account. The broken mirror symmetry in these materials induces both in-plane and out-of-plane PIE effects, with CrBAsS 2 exhibiting a particularly large out-of-plane response, reaching a d 31 coefficient of up to 0.50 pm V −1 . The intrinsic carrier mobility is governed by different scattering mechanisms depending on carrier type, carrier concentration, and material composition. Acoustic deformation potential (ADP) scattering is identified as the dominant mechanism determining total electron mobility, whereas ionized impurity, PIE, and ADP scattering can all play decisive roles in controlling total hole mobility, depending on the specific case.