LNNano - Brazilian Nanotechnology National Laboratory

Postdoctoral position at LNNano

The Brazilian Center for Research in Energy and Materials (CNPEM), jointly with the Brazilian National Council for Scientific and Technological Development (CNPq), offers one postdoctoral position related to the epitaxial growth of nanomaterials, as described below.

About the Project

Group V elements that are analog of graphene have attracted much attention due to their semiconducting band structures, which make them promising for next-generation electronic and optoelectronic devices based on two-dimensional materials. New 2-D elemental materials with a band-gap such as phosphorene and arsenene, are some examples. Most of these 2D materials are direct bandgap materials with a bandgap of less than 2.0 eV, which further limits their use in optoelectronic devices. A suitable 2D material with a direct bandgap for optoelectronic applications is arsenene – a monolayer of As atoms. Much attention has been diverted to arsenene to explore its physical properties under different conditions such as strain or electric fields. For instance, semimetal–semiconductor and indirect–direct band gap transitions can be driven by applying biaxial strain and electric fields perpendicular to the plane of arsenene. Also, under strain/stress arsenene behaves like a topological insulator.

The current route to high-quality electrical properties uses the exfoliation process to separate the layers (the so-called “scotch tape” method) – this approach is not suitable for mass production of devices. Molecular Beam Epitaxy offers the possibility of creating large areas of single-layer materials. However, there are many challenges to overcome along the way that may provide an excellent opportunity for an enterprising postdoctoral fellow.

 Key project aims

  • Develop the growth of 2D materials based on Group V compounds by MBE;
  • Characterize the structure, electrical and optical properties of these materials;
  • Investigate the properties of heterostructures containing different Group V and their application to devices;
  • Work in close collaboration with the theory group that will be responsible for the DFT calculations.

Requirements and how to apply

Requirements include a Ph.D. degree in Physics or Materials Science. Proficiency in spoken and written English is also required. Previous experience in UHV systems and thin-film deposition is a must. Experience in material growth using MBE is desired.

Candidates are invited to send a CV (as a pdf), including a brief description of research experience, by e-mail to cesar.bof@lnnano.cnpem.br.