Atomistic approaches, transport and excited state simulations for new materials

Abstract

Here we propose an investigation about the use of a combination of reactive atomistic methods, both classical and quantum, in the study of mechanical, electronic and topological properties of nanostructured materials. In the last few years me and my collaborators have put a lot of effort on the development and application of two reactive methodologies, namely the ReaxFF reactive potential and the Tight Binding Density Functional Theory (DFTB) approximation. Those studies were carried partially with the financial support of Fapesp (Grants: 2013/09536-0, 2014/15521-9 and 2018/03961-5) and other funding agencies, like CNPq (Grants: 308298/2014-4, 310369/2017-7 and 437034/2018-6) and Fundunesp (Fundação para o desenvolvimento da Unesp). Reactive methods allow us to describe and predict relatively complex behaviors for new materials, and have been used frequently in collaboration with experimental groups. In those collaborations, it is common to use reactive methods to understand the origin of particular mechanical or electronic properties originated in the molecular or nanoscopic scale. However, it would be desirable to complement these descriptions considering an approach that allow the study of dynamical properties of materials, thus broadening the scope of the investigations carried along with my collaborators. One way to obtain such effect would be to combine the present descriptions with more sophisticate models, able to describe excited states and/or transport phenomena analysis when those can be relevant. There are only a few groups in the country which have such technical capacity to effectively make combination of descriptions including various effects as explained before. This fact hinders the appearance of more national groups able to propose really innovative new materials with special properties. One of the aims of the present proposition is to contribute to the improvement of this situation. This will be realized studying the proposed systems using an approach that combines the techniques already utilized in the present collaborative projects with excited states and electronic transport descriptions made in collaboration with Professor's Niehaus Group(the hosting researcher of the project). The proposition is to apply this approach in two ways: the first one will be to investigate structural, electronic and transport properties in porous 2-dimensional materials, like graphenylene and similar structures. The other one will be to propose and simulate possible new nanodevices based on those materials. (AU)