Tunable ferroelectricity of group Ⅳ–Ⅵ nanowires under composition modulation

Abstract

Low dimensional ferroelectrics are anticipated to play a dominant role in micro/nano-electromechanical field. However, as their intrinsic size decreasing to one-dimension (1D), their ferroelectric polarization will weaken or even disappear, which severely limiting the further development of these promising materials. Therefore, it is of great significance to design one-dimensional ferroelectric materials with high-performance. In this work, first-principles calculations are employed to investigate the ferroelectricity and atomic configuration of MX (MX, M = Ge, Sn; X = S, Se) nanowires with composition tuning. Their ferroelectric characteristics, including spontaneous polarization Ps, transition barrier TL and TQ, Curie temperature Tc, as well as their stabilities, electronic structures, and transformation modes were systematically investigated. The findings indicate that their stability and forming tendency are strongly correlated with the bonding type. Moreover, all nine nanowires retained nanowires exhibit intrinsic 1D ferroelectrics with the maximal Ps of 6.40×10−10C/m for GeS nanowire and the minimum Ps of 3.95×10−10C/m for SnSe nanowire. The obtained calculation results indicate that the ferroelectric properties can be tuned by alteration of composition, which holds significant implications for the design and performance enhancement of 1D ferroelectric materials.