Phd Position

The Ernst Ruska-Centre (ER-C) for microscopy and spectroscopy with electrons is a center of excellence in advanced transmission electron microscopy (TEM) and spectroscopy for addressing topical problems in materials science, solid-state physics and chemistry, biology and soft matter. It comprises three divisions which each have a different focus. At ER-C-1 Physics of Nanoscale Systems) we carry out systematic characterizations using various complementary techniques, including the latest TEM based techniques, such as electron holography, HR-(S)TEM, high energy resolution spectroscopy, 4D-STEM, and ptychography. This enables the measurement of, e.g., electrical potentials and magnetic fields, polarization fields, built-in potentials, strain, and carrier dynamics on nanometer scales with high temporal resolution.

**Your Job**:
This PhD thesis aims to quantitatively study the initial stages of light conversion into electrical signals in Si-based photovoltaic devices. The research will employ off-axis electron holography, combined with ultra-fast laser excitation and ultra-short electron pulses, to monitor carrier dynamics. The goal is to identify and map regions of high quantum efficiency as well as recombination centers, thereby contributing to the development of improved photovoltaic designs.

Your tasks in detail:

- Preparation of electron transparent TEM lamellas
- Installation and alignment of optical equipment, operation and optimization of fs to ps laser sources
- Characterization of electrostatic potentials and excited carrier concentrations using off-axis electron holography
- Mapping of charge carrier lifetimes by synchronizing ultra-short laser pulses with ultra-fast beam blanker and detectors
- Analyzing the interaction of excited carriers with shallow and deep defects by measuring charge transition levels
- Investigation of carrier generation and recombination with different laser pulse specifications
- Evaluation, documentation and publication of the data obtained in the form of reports, manuscripts and presentations in English
- Collaboration with and co-supervision of research interns and students

**Your Profile**:

- Excellently completed master's degree in physics, chemistry, material sciences, engineering, or a related field.
- Solid knowledge of semiconductor physics, lasers, and optics. Ideally, experience in the field of transmission electron microscopy.
- High level of self-motivation, as well as enjoyment and skill in practical work.
- Willingness to take on responsibility for the laboratory and equipment.
- A high level of teamwork and enjoyment of cooperative collaboration.
- Furthermore, you can quickly familiarize yourself with new methods and techniques.
- Ability to work cooperatively with internal and external project partners.
- Very good written and spoken English skills.

**Our Offer**:
We work on the very latest issues that impact our society and are offering you the chance to actively help in shaping the change We offer ideal conditions for you to complete your doctoral degree:

- Interdisciplinary collaboration on projects in an international, committed and collegial team
- Excellent scientific equipment and the latest technology
- Qualified supervision by scientific colleagues
- A large research campus in the countryside, which offers the best opportunities for networking with colleagues and for sporting activities alongside work
- Flexible working hours and appropriate remuneration
- The opportunity to work flexibly (in terms of location), e.g. partly from home
- 30 days of annual leave (depending on agreed working time arrangements) and provision for days off between public holidays and weekends (e.g. between Christmas and New Year)

Targeted services for international employees, e.g. through our International Advisory Service