Global-Optimization-Based Theoretical Prediction of Novel Two-Dimensional Tellurene Allotropes

Two-dimensional (2D) monoelemental materials have attracted significant interest in materials science owing to their distinctive properties and promising applications in electronics and optoelectronics. However, existing 2D Te materials exhibit certain limitations that constrain their practical performance. Here, using first-principles calculations and the IM2ODE software package based on the differential evolution algorithm, we have predicted two novel 2D Te allotropes, Te-P1-α and Te-P1-β, composed of single chains different from traditional helical chains. The phonon spectra and ab initio molecular dynamics (AIMD) have verified the dynamic and thermodynamic stability of the structures. The band gaps of Te-P1-α and Te-P1-β calculated by the HSE06 functional are 1.85 eV (direct) and 1.26 eV (indirect), respectively. Te-P1-α and Te-P1-β exhibit high n-type Schottky barriers of 1.27 and 0.97 eV, respectively, indicating promising potential for applications in 2D Schottky barrier diodes (SBDs). Simultaneously, the excellent light absorption capacity of these structures across the visible light spectrum enables the development of high-performance optoelectronic devices. Our research results are expected to provide important guidance for the applications of novel 2D Te allotropes and the design of new 2D materials.