Two-dimensional semiconducting Lu2CT2(T=F,OH) MXene with ultralow work function and ultrahigh carrier mobility
As a new family of two-dimensional materials, MXenes have attracted increasing attention in recent years due to their widespread potential applications. In contrast to early transition metals in convention, here we expand the M element of MXene to the rare earth element lutecium. Based on the first-principles density functional calculations, the bare lutecium-based carbide MXenes Lu2C are determined to be stabilized in the T-type configuration. Furthermore, both fluorine and hydroxyl terminated configurations are found to be semiconductors, and their band gaps are suitable for semiconductors, visible and near-infrared optical devices. The Lu2C(OH)2 configuration shows a direct band gap and possesses ultralow work function of 1.4 eV. In regard to carrier mobilities, both of the Lu2CT2 (T = F, OH) MXenes exhibit high carrier mobilities. Especially, the electron mobility in the Lu2C(OH)2 MXene is found to be strongly anisotropic at room temperature, with values as high as 95.19 × 103 and 217.1 × 103 cm2/V•s in the zigzag and armchair directions, respectively, which makes Lu2C(OH)2 a promising material for nanodevices. Based on these predicted properties, our work widens the range of MXenes materials and their applications in semiconducting devices.