University of Gothenburg

Postdoctoral scholarship in triplet-triplet annihilation photon upconversion

The Department of Chemistry and Molecular Biology at the University of Gothenburg is offering a postdoctoral scholarship in triplet-triplet annihilation photon upconversion. You will explore how to replace molecular diffusion with exciton diffusion in solid state triplet-triplet annihilation upconversion systems. The placement is within the research group of Proferssor Börjesson, winner of the Göran Gustafsson prize in chemistry 2022 (the most prestigious national prize in science in Sweden), where you will get first class tutoring. Application deadline: 31 August 2022.


Solid state triplet-triplet annihilation photon upconversion

Triplet-triplet annihilation upconversion (TTA-UC) is a process that converts two low energy photons to one of higher energy. In order to maximise the upconversion efficiency, it is important to have a clear understanding of which factors drive the process. Furthermore, triplet exciton diffusion has fundamentally limited the development of high efficiency solid state TTA-UC materials. In principle, molecular diffusion must be replaced with exciton diffusion when going from solution to solid state. You will explore and learn to analyze the excited state dynamics of upconversion using optical spectroscopy (time-resolved and steady state) coupled to kinetic models. This in order to gather information on how to construct efficient solid-state upconversion systems. You will take projects within the field of photon upconversion from the discussion stage, over all steps in the project cycle to finished manuscripts. You will also be encouraged to implement your previous research knowledge into projects. This in order to break new ground within the broad research topic of upconversion, and also to promote your abilities to conceptually develop projects, which is of importance in a future career as an independent research leader. See the following group articles for an introduction to the research topic:

Ye, Mallick, Hertzog, Kowalewski and Börjesson
Direct Transition from Triplet Excitons to Hybrid Light–Matter States via Triplet–Triplet Annihilation
Journal of the American Chemical Society, 2021, 143, 19, 7501-7508.

Pfund, Steffen, Schreier, Bertrams, Ye, Börjesson, Wenger and Kerzig
UV Light Generation and Challenging Photoreactions Enabled by Upconversion in Water
Journal of the American Chemical Society, 2020,142, 23, 10468–10476.

Ye, Gray, Mårtensson and Börjesson
Annihilation vs. Excimer Formation by the Triplet Pair in Triplet-Triplet Annihilation Photon Upconversion
Journal of the American Chemical Society, 2019, 141, 24, 9578-9584.


GU 2022/1826

Scholarship period

The scholarship covers a period of 24 months.
Preliminary start date: 2023-01-01

Supervisor/contact person

Professor Karl Börjesson, +46766229099,


  • To be eligible for a postdoctoral scholarship at the Department of Chemistry and Molecular Biology, the recipient must hold a PhD degree within a relevant field. The applicant must not have been employed at University of Gothenburg in the past two years.
  • Please specify your experience, knowledge and/or interests necessary for this project. A suitable background for the applicant is a PhD within physical chemistry, optical spectroscopy or physics. A broad knowledge of spectroscopy with hands-on experience of steady state and time resolved optical spectroscopy, as well as experience in numerical modelling are expected from the applicant. Further is it expected that the applicant will have taken responsibility of research projects before. This will be evaluated based on the quality of first author publications.


Written application, including reference number, is to be sent via e-mail to the supervisor and must include the following:

  • CV
  • Personal letter stating the reasons why the study suits the applicant (maximum one page)
  • List of publications
  • References (2)

Application deadline: 2022-08-31

Information regarding scholarships

  • Remember that a scholarship is not an employment. Scholarships do not give rise to sickness benefits, compensation from the Social Insurance Office Agency or retirement pension.
  • The scholarship sum is paid out on two occasions.
  • Scholarships are tax-exempt.