Postdoc New Luminescent Materials for Sustainable Energy Technology: Towards a Photovoltaic Window

Imagine windows that generate electricity. You will use reactive magnetron sputtering to develop Yb³⁺-doped narrow-bandgap sulfide luminescent coatings that turn glass into solar power.

Job description

In this postdoc research project you will develop luminescent materials for building-integrated photovoltaic (BIPV) technology. You will make and study new types of strongly absorbing sulphide luminescent solar absorber materials, just a few hundred nm thick, that can convert the UV and visible part of the solar spectrum into infra-red luminescence. When applied as a coating to windows, these materials can enable a cost-effective electricity-generating PV-window following the principle of a Luminescent Solar Concentrator (LSC). An LSC harvests sunlight by absorbing, re-emitting, and subsequently guiding light, like in an optical fibre, to solar cells integrated in the window pane that convert the light into electrical power.

In this project you use reactive DC, RF or pulsed magnetron sputtering, the workhorse technology of the glass coating industry, to make the luminescent materials. Targeted materials are Yb³⁺-doped inorganic semiconducting sulphide materials, emitting in the infra-red spectral range, where silicon solar cells have high conversion efficiency.

To successfully develop new luminescent absorber materials, it is crucial that you gain a fundamental understanding of the physical processes underlying their luminescence mechanism. One of the scientific challenges is to understand how generated electron-hole pairs can transfer their energy to the luminescence centres. The strongest possible absorptions in an inorganic material are so-called bandgap absorptions, in which an electron is excited from the valence band (VB) to the conduction band (CB), leaving behind a hole in the VB. Although there are many materials (hosts) with a small bandgap that absorb the entire visible part of the solar spectrum (black materials), very few show efficient luminescence of doping ions. Such host-to-doping-ion transfer is often described as a resonant process between (self-trapped) exciton emission and doping-ion absorption. The materials in this project are selected to have a small exciton binding energy, making exciton-mediated transfer inefficient. Instead, sequential transfer of first the electron and then the hole is the anticipated transfer process to the Yb³⁺ luminescence centres.

The fundamental insights are obtained first by time- and temperature-resolved optical and luminescence spectroscopy, combined with a variety of techniques to analyse the structure, defect composition and morphology of the films. Secondly, fundamental understanding involves data interpretation and model development using knowledge of solid-state physics, optics and quantum mechanics. Ideally, the obtained insights will be used to select other materials with improved properties during your project.

The Energy Materials group at Delft University of Technology has more than 30 years of experience in luminescent materials research and collaborates with a start-up company and the glass coating industry to facilitate a route to large-scale application of the coatings as windows. You will work in a team, led by your supervisor, alongside PhD’s, technicians, a start-up company and the glass coating industry.

Job requirements

• a PhD in physics, inorganic (physical) chemistry or a similar field
• experience with magnetron sputtering
• a proven interest in, and experience with, experimental (materials) research

Experience with any of the topics mentioned in the job description is beneficial but not mandatory.

About TU Delft

Working at TU Delft means contributing to solutions that really make a difference.

At TU Delft, our people make the difference. With their knowledge and curiosity, our staff provide a high-quality education and conduct pioneering research that extends beyond the campus. You will have the opportunity to take the initiative, work with others, and grow as a professional.

Working at TU Delft means joining an international community of professionals and students. Together, we create knowledge, innovations, and solutions that help move the world forward.

Faculty Applied Sciences

With more than 1,100 employees, including 150 pioneering principal investigators, as well as a population of about 3,600 passionate students, the Faculty of Applied Sciences is an inspiring scientific ecosystem. Focusing on key enabling technologies, such as quantum- and nanotechnology, photonics, biotechnology, synthetic biology and materials for energy storage and conversion, our faculty aims to provide solutions to important problems of the 21st century.

Conditions of employment

• Duration of contract is 27 months. Temporary.
• An excellent pension scheme via the ABP.
• The possibility to compile an individual employment package every year.
• Discount with health insurers on supplemental packages.
• Flexible working week.
• Every year, 232 leave hours (at 38 hours). You can also sell or buy additional leave hours via the individual choice budget.
• Plenty of opportunities for education, training and courses.
• Partially paid parental leave.
• Attention for working healthy and energetically with the vitality program.
• If you need to relocate to the Netherlands for this job, TU Delft offers support to help make your move as smooth as possible, including relocation information, settling-in events, and a Dual Career Programme for accompanying partners.