The Study Of Rectifying Regularity Based On The ZMP Molecular Device With First-principles

With the development of technology, people are increasingly demanding for tool use, and hope the tool would more fine. Especially for the requirement of the computer, has experienced several generations of the update change. However, the traditional silicon-based devices face the challenge of the further miniaturization and energy. And the molecular devices will become the ideal candidate for replacing the traditional silicon-based devices. Here, in this thesis, the calculation used by non-equilibrium Green's functions combined with the density functional theory, we investigate the electronic transport properties based on the new zinc methyl phenalenyl (ZMP) molecular devices. We mainly investigated the spin filtering and rectifying effects of the ZMP molecule linked to two ZGNR electrodes (magnetization configurations) or two AGNR electrodes (non-magnetization configurations), respectively. And by adding the external magnetic field or by using different atoms to modify the hydrogenated edge of ZMP molecule to regulate the rectifying directions. The main contents are as follows:We investigate the electronic properties of a new neutral planar ZMP molecule is linked to the 4-ZGNR electrodes through a five-membered carbon ring, due to the ZGNR has three magnetic states, ferromagnetic (FM) state, antiferromagnetic (AFM) state and non-magnetic (NM) state, and the spin director can be changed by external magnetic filed. The results show in this magnetic devices the perfect spin-filtering effect occurred, meanwhile, the size and direction of spin-filtering effect can be changed by adding the external magnetic filed. Further analysis shows that these perfect spin-filtering effects are attributed to the intrinsic transmission selection rule of and -subbands in zigzag edged graphene nanoribbon.We investigate the electronic property of the nonmagnetic system, when sandwiched the ZMP molecule to the AGNR leads. Rectifier phenomenon is obtained and the rectifying directions will be changed by using different atoms to modify the hydrogenated edge of ZMP molecule. For further study, the mechanism of the rectifying is the different replaced atoms change the electron density of state and distributions.In order to attach more grateful rectifying effect, we take the NM-ZGNR as the electrodes, and adjust the ways of hydrogenated of the left ZGNR electrode edge. The results show a more grateful rectifying, also the rectifying directors is changed by different hydrogenated. Thus, how to improve the rectification effect of device has an important guiding significance to future.