Tek atomik katmanlı boron fosfor yapılarının oluşturulması ve işlevselleştirilmesi

Since the synthesis of graphene with its unique properties has increased the focus on novel two dimensional (2D) materials, successively new 2D materials from either layered or non-layered materials have been synthesized following the advances in thin film growth and characterization techniques. Hexagonal boron nitride (h-BN) is the runner-up material, which is structurally stable in hexagonal honeycomb form. h-BN is an insulator whereas, it is a good thermal conductor. However, the electronic and structural properties of these 2D materials are very susceptible to doping and adsorption, as such, these properties can be altered extensively. Therefore, we have examined the phosphorization of h-BN with varying concentrations, which leads to stable 2D boron phosphide at the ultimate limit. The lattice constant of the BN16−xPx alloy have been found to increase with increasing x. The planar geometry of h-BN is deformed and alloy turns into buckled structure until x > 0.75 (corresponding to (75% P) concentration). Beyond this point, planarity is recovered and planar monolayer h-BP achieved when all N atoms are replaced with P. Although 2D BP has not been synthesized yet, phonon spectrum analysis and high temperature molecular dynamics calculations indicate the stability of the system. Interestingly, while h-BN is an insulator, h-BP is semiconductor with 1.3 eV direct band gap. Owing to decreasing of electronic band gap with increasing x, it is possible to tune the band gap of BN16−xPx alloy, allowing various device applications in nanoelectronics. After proving of the stability of h-BP in monolayer form, we have elucidated the effect of doping and adsorption on electronic and structural properties of monolayer BP with selected atoms from Group III-IV-V atoms. The Dumbbell phase has been found to play a key role to stabilize the monolayer BP upon adsorption, suggesting full coverage of the monolayer BP surface. Evenmore, this new phase forms exothermically. Adsorption also leaves monolayer BP as small gap semiconductor with impurity characteristics of adsorbants. Also, we have shown that except for Al and Ga, these impurity adatoms carry small amount of magnetic moment in moderate temperatures. In addition, we have studied the substitution of monolayer BP with Group III-IV-V atoms. Based on our calculations, we have found that C and N can substitute P atom under ambient conditions. Nonetheless, only N atom selectively substitute for P atom, whereas C atom substitutes both for B and P giving rise to possible chemical etching of monolayer BP in the presence of excess C atom. Substitution of C for B/P results in metallic state in monolayer BP, while substitution of N for P leaves monolayer BP direct gap semiconductor. It is also found that none of these substitutions makes substrate magnetic. Using state-of-the-art computational tools based on the Density Functional Theory(DFT), we have calculated the structural and electronic properties of phosphorization of monolayer h-BN and doped monolayer h-BP.