Twisted Phosphorene Nanoribbons

Many different forms of structural deformations have been employed to alter the electronic structure of various two-dimensional (2D) nanomaterials in various optoelectronic devices [1]. Given the recent interest in the new class of 2D nanomaterials -- phosphorene, it is important to understand how the anisotropic strain-dependent electronic properties of low-dimensional phosphorene may be exploited for technological gain. Here, using first-principles density-functional theory, we investigate the mechanical stability of twisted one-dimensional phosphorene nanoribbons (PNR) by measuring its critical twist angle ($\theta_{\rm c}$) and shear modulus as a function of the applied mechanical torque [2-4]. We find a strong anisotropic behaviour in PNRs with different edge terminations and directions, and report the direct consequence of this applied mechanical stress on its corresponding electronic (and optical) properties. [1] E. S. Reich, \textit{Nature}, \textbf{506}, 19 (2014); [2] C. D. Reddy \textit{et al., Appl. Phys. Lett.} \textbf{94}, 101904 (2009); [3] E. M. Diniz, \textit{Appl. Phys. Lett.} \textbf{104}, 083119 (2014); [4] V. Sorkin and Y. Zhang, \textit{Nanotechnology}, \textbf{26}, 235707 (2015)