KU Leuven

Micro-processing stable optoelectronic perovskite thin films

Ku Leuven

Leuven, Belgium

The Roeffaers lab (http://www.roeffaers-lab.org) develops optical microscopy tools and assays to study a wide range of energy materials at under realistic conditions, at the smallest time and length scales possible. Currently, a major focus of the research team is development of next-generation metal halide perovskite-based materials and devices.

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Research outline

Solution-processed all-inorganic CsPbI3 perovskite is increasingly being considered for applications well beyond photovoltaics, for example, as the active regions within thin film photonic devices like cameras and LEDs. Its high-temperature optically active black phase (>320°C) is metastable relative to its non-perovskite yellow phase at room temperature (RT), representing a major impediment for real-world applications. In 2019, a fundamentally new and effective stabilization approach was developed by the Roeffaers Group to secure a RT black phase, based on interface/strain engineering (DOI: 10.1126/science.aax3878). Extending this recent discovery, a refined method for patterning the perovskite thin film surface with a micrometer-scale grid, via direct visible laser writing, renders ambient-stable black phase materials. This result strictly goes against current mainstream knowledge. To further develop this discovery and foster device-readiness, this project aims to comprehensively explore realistic scale-up thin film micro-processing options. Based on fundamental structure-property relationships provided by our local collaborating team, the successful applicant will develop a device readiness framework; from refining the pre-cursor solution and spin-coating procedure and scaling up clean-room microfabrication (masked UV-VIS and X-ray lithography), to prototyping photonic devices.

Job description

The main goal of this position is to further development existing perovskite thin film solution processing procedures and effectively combine them with micro-fabrication techniques (utilizing commercial setups, like masked UV-VIS lithography) to form stable thin films. Using proven stabilization routes which yield good thin film optical properties (i.e. PLQY, PL lifetimes and carrier transport), the project will realize stable working photonic devices and test their performance (pixel cross-talk, response sensitivity and time, etc.). All aspects of the work plan (materials synthesis, routine characterization and device fab and testing) will be completed in a supportive environment designed to help the applicant learn, grow and mature their multidisciplinary research skills.


We are seeking highly motivated candidates that hold a PhD in chemistry, physics or nanotechnology related subjects. Desirable scientific research experience includes:

- Clean room work (highly desirable)

- Glove box work

- Routine characterization of optoelectronic/semiconductor materials; XRD, SEM, AFM, PL-based studies…

- Photonic device fabrication and testing; i.e. LEDs, photodetectors…

- Lead halide perovskite thin film solution processing (i.e. spin and/or blade coating)

- Strong written and oral communication skills in English

The candidate should be open to interdisciplinary science and collaborations. KU Leuven offers in this respect is an ideal environment with a large number of science groups working on different (applied) subjects. The university is one of Europe’s oldest and most innovative academic institutions, and is situated in a medium-sized vibrant student town with a large international community.



We offer a post-doctoral fellowship for 2 years. During this period the candidate can also apply for personal fellowships from the Science Foundation Flanders (3 years) and/or Marie-Curie.


For more information please contact Prof. dr. ir. Maarten Roeffaers, tel.: +32 16 32 74 49, mail: maarten.roeffaers@kuleuven.be or Mr. Julian Steele, tel.: +32 16 37 28 67, mail: julian.steele@kuleuven.be.

You can apply for this job no later than February 23, 2020 via the online application tool

KU Leuven seeks to foster an environment where all talents can flourish, regardless of gender, age, cultural background, nationality or impairments. If you have any questions relating to accessibility or support, please contact us at diversiteit.HR@kuleuven.be.

Please apply via recruiter’s website.