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Advertising division: IEK-5 - Photovoltaics
Reference number: 2019M-091, Physics, electrical engineering

Master Thesis: Aligned metal nanowires as anisotropic transparent contact for thin-film solar modules

Your profile

  • Very good academic records in physics, electrical engineering, or related subjects
  • Good knowledge in solid state and semiconductor physics
  • Previous knowledge in the field of photovoltaics desirable
  • Experiences with laboratory work desired
  • Highly motivated individual
  • Self-reliance and analytical way of working
  • Structured working method, quick comprehension
  • Excellent language skills in German and/or English

Our offer

  • A pleasant working environment within a highly competent, international team in one of the most prestigious research facilities in Europe
  • You will be remunerated, supported by top-end scientific and technical infrastructure as well as closely guided by experts
  • You will have the opportunity to work with excited researchers from various scientific fields and take part in the development of new concepts and technology for photovoltaic devices
  • The project extends over 12 months, six month are remunerated.

The institute
The Institute of Energy and Climate Research, Photovoltaic (IEK-5, investigates both fundamental physics as well as technologies for efficient and cost effective solar cells. The research covers the entire spectrum of materials science, process and device development, materials and device characterization, and multi-scale materials and device modeling.

Transparent contacts are an inherent ingredient in most photovoltaic cells. The transparent contacts often consist of doped metal oxides (e.g. ITO or ZnO:Al) in some cases supported by a metallic grid. Random networks of metal nanowires are an interesting alternative as transparent contact. With the notable exception of grid supported transparent electrodes, most electrodes exhibit anisotropic conduction. However, the currents through the electrodes of a solar cell often follow one fixed direction. Hence the application of anisotropically conductive materials, which only conduct well in the desired direction, would allow a more favorable tradeoff between transparency and conductivity.

In addition, electrical losses in solar cells may roughly be divided in current losses (e.g. shunts, weak diodes), and voltage losses (e.g. series resistance, contact barriers). In the case that current losses are distributed over the solar cell area, anisotropic conduction can mitigate the losses as it hampers the current flow toward the defected areas. On the other hand, losses due to series resistance will be intensified as anisotropic conduction hampers the current flow around a defect area.

Aim and approach
The aim of this project is the demonstration of solar modules with anisotropically conductive contacts and the quantification of anisotropy effects on transparency and module performance. Meterlong metallic nanofibers will be prepared by electrospinning in collaboration with the Cologne University. All further processes and characterization methods are available at the IEK-5 in Jülich. Patterning processes for the nanofiber coatings have to be adapted from literature. Amorphous silicon solar cells will be prepared via plasma enhanced chemical vapor deposition of the silicon layers and magnetron sputtering for optional metal or metal oxide contact layers. The nanofibers, coatings, and devices will be characterized in detail using a UV-VIS spectrophotometry, current/voltage measurements under various irradiation conditions, and luminescence and infrared imaging. The resulting material properties and solar module performance will serve as input parameters and references for multiscale device modeling.

Dr. Jürgen Hüpkes
Institute of Energy and Climate Research – Photovoltaics (IEK-5)
Forschungszentrum Jülich
Telefon: + 49-2461-61-25 94

Send your application to:
Andrea Mülheims
Institute of Energy and Climate Research – Photovoltaics (IEK-5)
Forschungszentrum Jülich