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PhD studentship on the optical properties on implanted monolayer transition metal dichalcogenides

Advertising institute: PGI-9 - Semiconductor Nanoelectronics
Reference number: D127/2017, Physics

Peter Grünberg Institute 9 (PGI-9), Forschungszentrum Jülich has an open PhD student position on the optical properties of implanted monolayer transition metal dichalcogenides.

Monolayer transition metal dichalcogenides (TMDs) with the chemical formula MX2 (M=Mo,W, X=S, Se) have been shown to have unique optical properties. Their lattice symmetry, combined with the presence of heavy constituent atoms, leads to the coupling of spin- and valley- degrees of freedom, which can be addressed using circularly polarized light. The interaction of single photons with localized states in TMDs has been proposed as a method for accessing this spin-valley coupling. Single photon emission has been observed in TMDs, making them promising for future non-classical photon emitters. However, their potential as single photon sources in quantum optics is hindered by the fact that there are no effective methods of introducing single photon emission sites in a controllable way. One possibility is to introduce single dopant atoms into TMDs, in order to bind excitons and to facilitate single photon emission. Ion implantation, which will be used in this project, is the most common way of introducing low densities of impurities in semiconductors. Ion implantation into monolayers requires the use of very low ion energies (<30 eV), in order to maximize implantation probability and minimize defect formation. The use of ion implantation at energies of 10-20 eV has recently been verified and will be developed further in this project, in order to introduce optically active dopants into TMDs in a controlled way. The results of this project will have far-reaching applications: in addition to the modification of the optical properties of monolayer TMDs, the implanted ions will be relevant for the realization of p- and/or n-doping.

Project description
The selected candidate will characterize the optical signatures of dopants in MoS2 down to the single atom level and will integrate selected materials in single photon emitting sources. A variety of optical characterization techniques will be used, including low temperature photoluminescence and photoluminescence excitation spectroscopies. As optical methods will have to be optimized for the measurement of specific samples, part of the project will involve the development of optical setups. The project will involve the preparation of samples for implantation, as well as devices from the implanted monolayers using microelectronic fabrication techniques. It is a part of a larger effort and will include collaboration with partners who will perform low energy implantation, transmission electron microscopy of the implanted samples and density functional theory calculations to support the experimental effort.

Optical characterization will be carried out in the laboratories of PGI-9, while sample and device preparation will be carried out in the Helmholtz Nanoelectronic Facility in Forschungszentrum Jülich.

Job requirements
We welcome applications from candidates with a Master degree in physics and with a background and interest in optics and photonics. Candidates must have a strong aptitude in experimental physics and the drive and capacity to work independently. A theoretical background in solid state physics is required. Familiarity with programming is highly desirable.

Conditions of employment
We offer a full time appointment for three years and a gross monthly salary according to DPG guidelines. The successful candidate will be enrolled and graduate with a PhD from the Department of Physics in RWTH Aachen.

Forschungszentrum Jülich aims to employ more women in this area and therefore particularly welcomes applications from women. We also welcome applications from disabled persons.

Information and application
The deadline for application is 28th February 2018. Please contact Prof. Beata Kardynal ( to apply or for more information. The application should contain the following documents:

  • Application letter.
  • Curriculum vitae including two names of potential referees.
  • Grade transcripts and BSc/MSc diploma (typically B.Sc. and M.Sc.).

Prof. Beata Kardynal
Peter Grünberg Institute
Forschungszentrum Jülich