Mechanical and electronic properties of 2D-phthalocyanines under external strain

Abstract

We present our study on the mechanical and electronic properties of two-dimensional phthalocyanines (2D-Pc) under external strain using first principles and p_z-orbital tight-binding model calculations. The Poisson's ratio and in-plane stiffness calculated in the harmonic elastic strain range are found to be 0.43 and 73.41 J m⁻², indicating that 2D-Pc is much softer than graphene. The 2D-Pc can bear the same critical uniform strain as pristine graphene, which reduces the hopping integrals of π-electrons and narrows the width of the bands near the Fermi level. Consequently, the band gap and effective masses of carriers undergo ascending trends as the strain increases. The present study provides meaningful insight into the strain induced variation of electronic transport performance in 2D-Pc and other 2D tetrapyrrole macrocyles.