prof. Giuseppe Portale

Cala Gonzalez

Optimizing the fabrication and performance of pH-adjusted and solution-processed NiOx hole transport layer in organic solar cells.

Supervisor: Maria Antonietta Loi

Research group: Photophysics & Optoelectronics – ZIAM

To improve the efficiency and processing of organic solar cells (OSCs) the hole transport layer (HTL) has become a focused area of research as it is currently limited to a few materials. Hybrid HTLs combining metal oxides, such as Nickel oxide, with carbazole-based self-assembled monolayers (SAMs) have emerged as a robust and high efficiency alternatives. However, the expensive production of nickel oxide and its complicated defect chemistry has limited its implementation in organic solar cells. In this research project I have focused on optimizing the synthesis and efficiency of the NiOx HTL in p-i-n structured OSCs by creating a simple recipe that can manipulate the Ni oxidation state using non-toxic reagents and extending the variety of interfacial materials by applying novel carbazole-based SAMs for passivation of NiOx for a versatile HTL.

Intra-operative Pathology Assisted Fluorescence Guided Surgery – Tumor Edge Detection.

Supervisor: Prof. Dr. Pieter van der Zaag

Research Group: Optical Molecular Imaging Groningen (OMIG) – Universitair Medisch Centrum Groningen (UMCG)

Surgeons currently rely on visual and tactile information to distinguish tumours from healthy tissue, which can lead to incomplete removal of tumours and higher recurrence rates due to tumour-positive or close margins. Fluorescence-guided surgery addresses this by using injected fluorescent molecules that bind to tumour-specific markers, providing clearer visual guidance during resection. This technique, combined with pathology assessment, enhances surgical precision and reduces the need for additional treatments such as reoperation, radiotherapy, or chemotherapy. This project will aim to validate a standard fluorescence analysis procedure that can be used during surgery to distinguish tumours from healthy tissue, thereby providing surgeons and physicians with a valuable technique to perform more precise tumour resections. 

Design of Metal Borides Inks as Hard and Super-hard Coatings

Supervisor: Loredana Protesescu

Research group: Nanomaterials Chemistry – ZIAM

Boron-based materials are a unique class of materials because similar to carbon, boron can form various allotropes depending on the composition and concentration of the boron in the compound. Boron can bond with metal creating a material known as metal borides (MₓBᵧ). Generally, metal borides can be classified into two subcategories such as metal-rich boride where the metal dominates over the boron and boron-rich boride where the boron composition is higher than metal. This research will focus more on the boron-rich metal diborides with the composition of MB₂ and its application as a hard coating,  We synthesized metal diborides using a solid state reaction method and make molecular inks out of the metal boride and attempted to make thin film and then test the hardness of the thin film using nanoindentation. This project has a bright potential to be developed as a means to  produce hard coatings for use in harsh conditions.

Modeling Quantum Transport in Magnetized Graphene via Proximity-Induced Spin Splitting

Supervisor: prof. dr. ir. Bart van Wees

Research Group: Phyisics of Nanodevices – ZIAM

This project investigates the quantum Hall effect (QHE) in magnetized graphene induced by proximity to the antiferromagnetic insulator CrSBr. Using a matrix-based edge channel transport model, we simulate both local and non-local resistance behavior in Hall bar devices, capturing key features such as asymmetry and the coexistence of electron and hole carriers near the compensation point. Our simulations explore the role of spin-dependent transmission and scattering, aiming to reproduce experimental observations and provide insight into the spin-charge coupling mechanisms enabled by proximity-induced exchange splitting. The model is iteratively refined to incorporate Landau level occupation, energy-dependent scattering, and two-carrier transport dynamics, advancing understanding of spin-polarized quantum transport in 2D heterostructures.

Modeling of Fatigue Phenomenon in Hafnia-based Ferroelectrics

Supervisor: Erika Covi

Research group: Bio-inspired Circuits & Systems – ZIAM

The discovery of ferroelectricity in Hafnia (HfO₂) has revived the interest in ferroelectric devices due to their CMOS compatibility and scalability. Combined with properties such as non-volatility, high endurance, and analog/multilevel memristive behavior, Hafnia-based ferroelectrics have become highly desirable in established memory device research as well as rapidly emerging fields like neuromorphic (brain-inspired) computing.

Even though Hafnia-based ferroelectrics show good endurance (>1010 cycles), the field-cycling behavior also shows two interesting trends with remnant polarization (Pr), an important parameter linked to the non-volatility. Initial cycles (up to ~103) show a gradual increase in Pr, known as wake-up, and later cycles, till dielectric breakdown, show a gradual decrease in Pr, known as fatigue. These phenomena are crucial to understanding the behavior of devices with the number of cycles, and incorporating these into a computationally light model improves predictive reliability. The current study navigates the complex and varied mechanisms of fatigue in Hafnia-based ferroelectrics and proposes physical models that would enable comprehensive design-technology co-optimization (DTCO).

Light Driven Exciton-Control

Supervisor: Maxim S. Pchenitchnikov

Research group: Optical Condesded Matter Physics Group – ZIAM

Natural light-harvesting antennas, such as chlorosomes in green sulfur bacteria, are highly efficient at transferring energy using delocalized excited states called Frenkel excitons. These natural systems provide inspiration for efficient energy-transfer design, but their complex structure and low optical stability make them difficult to study directly.

An attractive synthetic alternative is offered by amphiphilic cyanine dye molecules, which self-assemble into exceptionally homogeneous double-walled nanotubes in aqueous environments, resembling the structure of natural chlorosomes. The lowest-energy excitonic peaks of the inner and outer walls are spectrally distinct; however, their higher-energy transitions significantly overlap, resulting in considerable spectral congestion. Isolating optical transitions specifically from the inner wall is therefore crucial to enable precise theoretical modeling and detailed experimental investigation of exciton coherence and energy-transfer mechanisms, without interference from the outer wall. Existing methods to suppress outer-wall optical response generally rely on chemical interventions in liquid-phase environments, making them unsuitable for solid-state applications and motivating efforts to develop more refined, non-invasive techniques.

In this project, we present a novel experimental strategy that selectively deactivates outer-wall absorption using controlled optical irradiation. Advanced ultrafast spectroscopy combined with high-resolution electron microscopy is employed to comprehensively characterize the structural and optical properties of these irradiated nanotubes. Our method is simple, flexible, and works in both liquid and solid environments. It opens up new possibilities for studying and controlling exciton behavior in artificial systems, helping us take steps toward exciton-based technologies inspired by photosynthesis in nature.

Out-of-plane Magnon Transport on the van der Waals Antiferromagnet CrPS₄

Supervisor: prof. dr. ir. Bart van Wees

Research group: Physics of Nanodevices – ZIAM

The research on magnon (quantized spin wave) transport is interesting for both the understanding of fundamental physics and for novel applications. Magnons carry spin information without the movement of charge carriers, offering a pathway for low-power computing, wave-based logic, and novel memory concepts within the emerging field of magnonics.

While magnonics traditionally leverages in-plane propagation in materials like yttrium iron garnet (YIG) and chromium thiophosphate (CrPS₄) due to mature planar fabrication techniques, probing out-of-plane transport (perpendicular to the atomic planes in a layered van der Waals magnet) is crucial for exploiting the unique properties of layered magnets in magnonic circuits. However, fabricating reliable vertical devices presents significant challenges: it requires precise stacking of atomically thin layers, maintaining clean interfaces, and establishing electrical contacts orthogonal to the plane – complexities exceeding standard in-plane lithography.

Our work on CrPS₄ establishes a platform for investigating out-of-plane magnon dynamics in atomically thin systems, overcoming key fabrication complexities and opening the possibility for vertically integrated magnonic devices benefiting from the rich physics of 2D magnets.

The Effect of Chlorosome Tube Orientation on Energy Transfer.

Supervisor: Thomas la Cour Jansen

Research Group: Theory of Condensed Matter – ZIAM

Green sulphur bacteria are known to live in low-light environments. As a result, their light-harvesting antennae complexes, called chlorosomes, have evolved to be incredibly efficient at energy transfer. The chlorosomes consist of tube and lamella shaped bacteriochlorophyll aggregates. Previous research has shown that for lamella, the energy transfer rate is highly dependent on the angle of rotation between the involved lamella sheets. This raises the question of whether a similar effect applies to parallel and anti-parallel tube systems as well. Therefore, this project aimed to establish the role of tube orientation in such systems by modelling the energy transfer in otherwise identical parallel and anti-parallel chlorosome tube systems. The results of this project may inspire the design of synthetic light-harvesting aggregates. 

Hydrothermal Synthesis of Manganese-Based Magnetocaloric Materials

Supervisor: Graeme Blake

Research group: Solid State Materials for Electronics (SSME) – ZIAM

Hydrogen liquefaction is a critical step in enabling a clean hydrogen economy, but current methods are energy-intensive and costly. Magnetocaloric materials—solids that heat up or cool down in response to magnetic fields—offer a promising, energy-efficient alternative for cryogenic cooling. This project explores the hydrothermal synthesis of rare-earth-free, manganese-based perovskite materials with promising magnetocaloric properties for efficient hydrogen liquefaction. Single-crystal X-ray diffraction is used to determine the atomic structure of promising crystals, while powder X-ray diffraction confirms their phase purity. Magnetic measurements using a Magnetic Property Measurement System (MPMS) help assess the entropy change and cooling potential of the materials. By correlating crystal structure with magnetocaloric performance, this research aims to advance the development of sustainable cooling technologies.

Spiropyran-based Responsive Polymers for Switchable Adhesive Properies

Supervisors: Batuhan Özyürek, prof. Ben L. Feringa

Research group: Ben Feringa Research Group – Stratingh Institute for Chemistry

Have you ever imagined an adhesive you can turn on and off at will? That’s exactly what this project delivers: a polymer matrix of poly(butyl acrylate) and poly(methyl methacrylate) infused with a mussel-inspired spiropyran-catechol molecule. A brief flash of UV light switches the spiropyran into its “open” form, revealing sticky catechol groups and boosting adhesion. A small thermal application then reverts the spiropyran to its “closed” state, hiding the catechols and reducing the adhesive properties. The result is a fully reversible switchable adhesive that sticks on demand. Additionally, an unexpected result was discovered during the research. Join my talk at the symposium to find out more! 

SAXS/WAXS Study of Multiblock Copolymers and Microspheres

Supervisor: prof. Giuseppe Portale

Research group: Macromolecular Chemistry and New Polymeric Materials

The effectiveness of nanocarriers in drug delivery depends strongly on their internal structure, yet obtaining reliable structural information at the relevant length scales remains a challenge. This project explores the use of small- and wide-angle X-ray scattering (SAXS/WAXS) to characterize multiblock copolymer microspheres designed for controlled drug release applications.

The goal is to determine whether SAXS/WAXS can provide meaningful, quantitative insights into key internal parameters such as crystallinity, phase separation, domain size, and the distribution of loaded material. By combining careful experimental design with numerical modeling, we aim to extract structural features that can be directly correlated with functional behavior.

This is an exploratory study, aiming not only to validate the use of SAXS/WAXS in this context, but also to deepen our understanding of how internal morphology affects drug delivery performance.

Smart STED microscopy for super-resolution imaging of live mitotic cells

Supervisor: dr. Rifka Vlijm

Research group: Molecular Biophysics – ZIAM

Mitosis is the process by which a single cell divides into two daughter cells. Many vital processes occur during mitosis, which are often related to degenerative diseases or cancers. 

Super-resolution imaging of live mitotic cells provides valuable structural and dynamical information at sub-diffraction length scales. However, mitosis is a rare event, as cells spend only a small portion of time in mitosis. Consequently, acquiring large datasets of live mitotic cells is labor-intensive and time-consuming. In this project, we develop a smart microscopy approach to identify mitotic cells autonomously and subsequently make super-resolution images. Our approach is based on repeatedly scanning a large sample area with epifluorescence wide-field microscopy and creating a track for every cell. Based on these tracks, we identify for each cell individually whether it is mitotic or not, and perform STED imaging only on mitotic cells.

Crowding Effects on Complex Coacervation

Supervisor: Marleen Kamperman

Research group: Polymer Science – ZIAM

Spider silk is renowned for its exceptional material properties, including extreme toughness. However, the inability to properly farm spiders limits the large-scale use of their silk. This challenge has driven the development of methods to artificially spin materials of similar properties, with one promising approach involving the use of microfluidic chips to mimic the biological spinning processes. By utilizing flows of different salt concentrations, these chips provide control over complex coacervation, a phenomenon in which two oppositely charged polymers associate to form a liquid-liquid phase separation, characterized by a dense polymer-rich phase and a dilute polymer-poor phase.  However, to ensure flow stability for reproducible fibers, a thickening agent is typically added. This project focuses on the effect of the thickening agent PEG on the final coacervate properties of a PSS-PDAMDA coacervate.

Composition Uniformity of Bulk and Surface MoWTe₂ van der Waals Material

Supervisor: Antonija Grubišić Čabo

Research group: Experimental Nanophysics with Advanced Spectroscopic and Structural Analysis Methods – ZIAM

Atomically thin layers of transition metal dichalcogenides like MoWTe₂ represent a unique platform for developing next-generation electronic devices due to their exceptional tunability through doping, strain, and functionalization. However, the substitutional doping of WTe₂ crystals with Mo using chemical vapour transport growth was found to create Mo-rich islands that introduce electronic inhomogeneity. These compositional fluctuations can degrade device performance, thus necessitating the need for precise synthesis control for reliable optoelectronics and nanoelectronics.

Using a multi-technique approach combining scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive spectroscopy (EDS), the chemical inhomogeneity of the surface and bulk of this ternary compound was quantified, revealing persistent Mo/W variations. The UHV-exfoliated flakes were further reported to exhibit the nanoscale inconsistencies in Mo/W ratios as well.