Structure Stability And Electronic Properties Of Phosphorene Allotropy And Their Oxidized Derivcitives

In 2014, a new type of two-dimensional material named as phosphorene was peeled off from the block black phosphorus and caused wide research interests due to its novel electronic properties. Because phosphorus atom prefers the way of sp3 hybridization, phosphorene may have many allotropes. So far, many different phosphorene allotropes, such as black phosphorene(?-P), blue phosphorene(?-P), ?-P,?-P and so on, have been proposed. The sp3 hybridized configuration of phosphorene makes it has lone pair electrons at its surface, which makes phosphorene prefers to combine with oxygen and thus forms surface oxidation. Surface oxidation will influences the properties of phosphorene on the electronic and mechanical at a different level. Now someone research the surface oxidation of black phosphorene and find that after the surface oxidation the structure of black phosphorene will appear deformation but still can exist steadily. After the surface oxidation, the bang gap of black phosphorene will reduce from ~ 1eV to ~ 0.6eV, but still is the direct band gap.Researchers believe that we may prepare phosphorene by CVD method in future.Considering that phosphorene has a lot of similar isomer and different isomer has similar stability, different structure of phosphorus may coexistence, when using CVD method preparation of phosphorene. Therefore, it's very necessary to study the stability and the electronic structure of phosphorene allotropes and the oxidized phosphorene derivatives. In order to fill such a research gap in this field, we mainly do researches in the following two aspects:(1)Using the first principles calculations based on density functional theory as implemented in vasp package, we studied the structure, stability and electronic properties of a new phosphorene allotrope, the tricycle red phosphorene. Tricycle configurations of phosphorene can be seen as the recombination of the configuration of stirrup phosphorene and chair phosphorene. The thermodynamic stabilities of the three different configurations of phosphorene were similar, and thus we believe that they have great opportunities to coexist with each other. At the same time, we studied the dynamic stability, electronic property and work function of tricycle phosphorene in detail. In the end, we investigated the modulating effect of stress on the electronic property of tricycle phosphorene found that its band gap will change from direct to indirect and then from semiconductor to metal.(2)Using the first principles method based on density functional theory, weresearched the stability and electronic properties of the six surface oxidation allotropes of phosphorene. We found that the phosphorus oxide structures will produce deformation. Other distorted configurations of phosphorene oxide are more favorable than the configuration of black phosphorene oxide in thermodynamic stability. The most stable structure is confirmed to be the distorted twist-boat one. We then studied its dynamics stability and confirmed it is dynamically stable. The electronic property of the twist-boat phosphorene oxide is also investigated. And we found that it is also an indirect band gap semiconductor with a band gap of 0.814 eV.