PhD student in ultrafast spectroscopy of organic semiconductors

We are seeking a PhD-level researcher for Dr. Gillett's research group at the Department of Electronic and Photonic Materials within the Department of Physics, Chemistry and Biology (IFM). The employed PhD student will work in collaboration with the Swedish company Epishine AB in a research project funded by the Åforsk foundation, where ultrafast optical spectroscopy is used to investigate degradation mechanisms in organic solar cells. The PhD student will also have the opportunity to utilize the group's advanced spectroscopic setups to conduct their own research within the broader research area of organic materials. Currently, the research group studies organic solar cells and OLED systems, vibronic coupling in organic molecules, molecular photoswitches, circularly polarized luminescence, and photocatalysis.

Your duties The project aims to understand stability and degradation mechanisms in the light-absorbing layer of organic solar cells under conditions relevant to commercial applications. To achieve this, we will use a unique approach where ultrafast optical spectroscopy is used to investigate how material degradation affects the fundamental photophysics of the organic materials that enable the component's function (see https://doi.org/10.1016/j.joule.2023.03.002 for a recently published example of this method from the research group). The project is carried out in collaboration with the Swedish company Epishine AB (https://www.epishine.com/), which is also based in Linköping and is currently working on the commercialization of organic solar cells for indoor use.

You will be responsible for performing measurements with transient absorption spectroscopy – from the visible region to the mid-infrared wavelength range – on samples consisting of organic solar cells from Epishine AB. The purpose is to understand how the materials' photophysics are affected by different types of degradation processes. This is complemented by steady-state spectroscopy (UV-Vis, photoluminescence/PLQY, FTIR) as well as morphological and computational characterization in collaboration with other researchers, to provide a complete picture of the degradation mechanism under realistic operating conditions. Through this work, you will develop new design principles for organic solar cell materials, which has direct relevance for the technology's commercial applications.

Additionally, Dr. Gillett encourages his research group to take their own initiatives and develop their own research projects. Therefore, the person who is awarded the position is given the freedom to also explore other topics within the broader areas of organic materials and ultrafast spectroscopy during the doctoral studies. In this way, you will have the opportunity to develop into an independent researcher, ready for a career in academia or industry.

As a PhD student, you will devote yourself to your doctoral education and the research project in which you are included. Your work may also include teaching or participating in other departmental duties, up to 20 percent of full-time employment.

Your qualifications You have completed a degree at the advanced level in physics, chemistry, materials science, or a related subject area, or have completed courses amounting to at least 240 higher education credits, of which at least 60 credits are at the advanced level, or have otherwise acquired substantially equivalent knowledge.

In addition, the following requirements are made for the position: Previous experience working with organic materials or perovskite materials. A high degree of drive and independence, good problem-solving skills, and a documented ability to work in teams. Ability to communicate fluently in English (both oral and written).

The following merits are not a requirement but are considered very valuable for the position: Previous experience working with organic photovoltaic materials and components, including stability measurements. Experience in independently performing measurements with ultrafast optical spectroscopy, including but not limited to transient absorption and time-resolved photoluminescence. Experience working with laser systems, especially femtosecond and nanosecond pulsed laser sources. Good programming proficiency (e.g., Python, MATLAB, LabView) for developing your own code to perform experiments and analyze experimental data.

Finally, a statement of purpose must be attached to the application, where you describe how your background and skills make you suitable for the research project in organic solar cell technology. Also attach a short description of your own research interests as well as an idea for an additional research project that you would like to explore within the group. Note that this does not necessarily need to be within the field of organic solar cell technology.

Your workplace You will be employed in the research group led by Dr. Alexander Gillett (https://liu.se/en/employee/alegi69) at the Department of Electronic and Photonic Materials (EFM): https://liu.se/en/organisation/liu/ifm/efm. Here you will become part of a small (currently the group leader and approximately five researchers) and supportive team, where critical thinking and designing one's own research direction is strongly encouraged.

About the employment Upon commencement of employment, you will be admitted to the doctoral program. The employment is fixed-term for normally four years full-time. Extension of employment up to five years occurs based on the degree of teaching and departmental duties. For special reasons, further extension may occur. You will initially be employed for one year, and thereafter the employment will be renewed for a maximum of two years at a time, based on the achieved study plan. Commencement by agreement.

Salary and benefits The PhD student's salary is regulated according to a locally agreed salary scale.

Application You apply for this position by clicking the "Apply" button. Your application must be submitted to Linköping University no later than October 5, 2026. Applications received after the application deadline will not be considered. Welcome with your application!