Theoretical investigation of the effect of mole fraction on the electronic and optical properties of a binary armchair antimonene-phosphorene nanoribbon

In this work, the electronic and optical properties of a binary armchair antimonene-phosphorene nanoribbon have been studied with a variation of the P mole fraction by first-principles calculation method based on density functional theory. The calculated cohesive energy shows that the stability of the binary SbP nanoribbon increases by increasing the molar fraction of phosphorus to 100%. We have demonstrated that the band gap of SbP nanoribbons can be modified by applying different mole fractions. The band gap value of SbP nanoribbon increases firstly up to mole fractions of approximately 50% and decreases up to 80% and then increases. A direct-to-indirect and an indirect-to-direct gap transitions occur at 5 to 75% (except for 35%) and 80 to 100% mole fractions, respectively. The optical properties of the mentioned structures with different mole fractions are analyzed, and it is found that the optical properties of binary SbP nanoribbons changed by P mole fraction; and also, the light absorption peak is mainly concentrated in the ultraviolet region. Compared with the pure antimonene, the light absorption is significantly enhanced after increasing the mole fraction of phosphorus to 100%. From a theoretical point of view, our results can offer promising applications in electronic and optical nanodevices.