Wide bandgap perovskite photovoltaics are promising for indoor energy harvesting, particularly in low-power electronics and Internet of Things (IoT) applications. However, phase segregation remains a major challenge, affecting efficiency and stability. In this study, we focused on characterizing phase segregation in Cs₀.₂FA₀.₈Pb(I₀.₄₅Br₀.₅₅)₃ perovskite films using advanced spectroscopic and imaging techniques. These methods provided a detailed analysis of ion distribution before and after light illumination, revealing crucial insights into the dynamic evolution of halide segregation.

18. Solving the triplet problem in fluorescent proteins

Thomas Bradbury, Physics and Astronomy, 1-2pm

For decades fluorescent proteins (FPs) have played an essential role in both biological and medical research. As FPs are genetically-encodable fluorescent markers they can be used with macroscopic imaging methods to observe different cell structures at the level of individual molecules. However, FPs have their limitations with both photobleaching and phototoxicity causing problems in fluorescence microscopy. Little is known about the mechanisms of these processes but it is theorised that the triplet state plays an important role in these mechanisms. Recently it has been shown that reverse intersystem crossing (RISC)might play an important role in reducing photobleaching, and that this RISC pathway can be used to make a fluorescent protein spin qubit. Using transient absorption in the NIR region we hope to better understand triplets in various FPs, with the hope of figuring out how we can improve FPs to make them more robust and encourage further development.

22. ZrSe3 - The van der Waals crystal ideal for tuneable room temperature light-matter coupling

Timothy Chester-Parsons, Physics and Astronomy, 1-2pm

Van der Waals materials are an exciting class of semiconductors composed of atomically thin layers held together by weak interlayer forces. By carefully tuning their interactions with light, we can reach the strong coupling regime, where light and matter merge to form hybrid quasiparticles known as polaritons. This phenomenon unlocks new possibilities for future technologies, from energy-efficient lasers to quantum computing. In this research, we demonstrate how strong coupling can be achieved at room temperature and actively controlled by leveraging the optical properties of ZrSe3, paving the way for potential compact, and tuneable photonic applications.

26. Green solvent-based FAPbI3 perovskite solar cells: Intermediate phase stabilization in ambient air processing

MirKazem Omrani, Physics and Astronomy, 1-2pm

Exceeding 26% efficiency with improved output power stability in recent years has made researchers more optimistic about the commercialization of perovskite solar cells as a future photovoltaic technology. However, one of the issues hindering their industrialization is the development of non-toxic solvent-based ambient preparation techniques for perovskite thin films, which can reduce manufacturing costs by eliminating the need for an inert gas-filled glove box. In this work, we show that the combination of methylammonium chloride (MACl) with excess lead iodide as an additive to perovskite precursor ink can stabilize the intermediate α-phase of FAPbI3 during coating process in ambient air leading to δ-phase impurity-free uniform perovskite thin films with improved crystallinity. Accordingly, nearly pure FAPbI3 -based perovskite solar cells were developed in high relative humidity air (> 40%) using a triethyl phosphate (TEP)-based green solvent system that delivers a high PCE of 18.6%.

29. Topological Edge states in Inverted hBN nanograting structures

Oscar Palma Chaundler, Physics and Astronomy, 1-2pm

Description of techniques used in order to fabricate atomically thin structures without the need of using any chemic substances. In addition, a brief explanation of the properties that the fabricated structures showed when excited with white light.

32. Directional superradiance in chiral waveguide-coupled quantum dots

Aspen Fenzl, Physics and Astronomy, 1-2pm

This combined theoretical and experimental work investigates the effect of environmental factors on the collective behaviour of quantum dots (QDs) in photon-based systems, essential for scalable quantum technologies. Light emitted from a group of indistinguishable atoms arrives in a short, high-intensity burst known as superradiance. This phenomenon results from many-body entanglement due to indistinguishability of the QDs. While there has been much study of superradiance in free space and structured waveguides (WGs), the potential of chiral coupling in 1D systems has yet to be explored. We aim to observe superradiance in directional WGs and see how dephasing, chiral contrast, and phase separation impact dynamics. Using established theory, we construct a model to explore how environmental factors influence observable superradiance. Simulations show superradiant behaviour is enhanced when QDs are chirally coupled, facilitating our understanding and control of many-body quantum effects.

36. The Evolution and Dissolution of Young Stellar Clusters

Megan Allen, Physics and Astronomy, 1-2pm

When giant gas clouds collapse under their own gravity, groups of stars form. These groups can be hundreds to thousands of stars, which may be bound together by gravity; this is a stellar cluster. Through interactions between the stars these clusters change shape, spread out, and eventually dissolve into their host galaxy, as stars will get so far away that they are no longer held in by the gravity of the cluster. We use simulations to see how these clusters evolve over time, and what effect the host galaxy has on the evolution and dissolution of stellar clusters.

We find that the force of gravity from the host galaxy always drastically changes the shape of a cluster. However, it can make some clusters dissolve faster, and others slower, than if there wasn’t a host galaxy. This is because, after stars have left the cluster, the gravity of the galaxy can pull some stars back in. In smaller clusters this has a huge effect, but on larger clusters it is mostly negligible.

42. Forward electron reconstruction for run4 and beyond

Lucy Lewitt, Physics and Astronomy, 2-3pm

Describes work on electron reconstruction that is required for upgrades to the ATLAS detector system as part of the transition from the Large Hadron Collider to the High Luminosity Large Hadron Collider. This work involved modifying existing software to make use of charged tracks in regions of the ATLAS detector with lower spatial resolution ElectroMagnetic Calorimeters than had been used previously.

47. Powered by the Sun: 2D Perovskites for Solar Energy

Sophie Tucker, Physics and Astronomy, 2-3pm

Two Dimensional Perovskites are an emerging class of semiconducting materials that demonstrate promise in developing new technologies for photovoltaics. They have potential in developing solar cells with improved sunlight-to-electricity conversion efficiency, an important factor in reducing costs and improving the global accessibility of solar energy. Compared to typical silicon-based solar panels, perovskites could offer easier fabrication routes and are composed of earth-abundant materials. My research aims to use layered (2D) perovskites to improve the operational stability of these materials by implementing new organic cations into the perovskite structure.

49. Integration of perovskite solar cells with curved, and rigid carbon fibre-reinforced polymer composites

Timothy Thornber, Physics and Astronomy, 2-3pm

As prevalence of electric propulsion in vehicles and other mobile applications grows, the ability to self-charge is highly desirable. Perovskite solar cells (PSCs) represent a route towards achieving this goal, combining lightweight with high power generation (high specific power). Typically, lightweight devices are fabricated onto flexible substrates and then adhered to a surface of interest, e.g. an aerofoil. However, these surfaces are often curved in two dimensions, complicating the lamination process. Instead, by using ultrasonic spray coating, devices can be fabricated directly onto the surface of interest, eliminating the unnecessary weight of the substrate, thus boosting specific power. These surfaces are often made from high specific strength materials such as carbon fibre-reinforced polymer (CFRP). CFRP presents additional challenges for fabrication, e.g. surface roughness and electrical conductivity. Here, we discuss our work on fabricating directly integrated PSCs on CFRP.

60. The Biophysics of the Main Synthase During Gram-Positive Bacterial Cell Division Using AFM

Matthew Barker, Physics and Astronomy, 2-3pm

This poster will show the various structures seen during the division cycle of Staphylococcus aureus using Atomic Force Microscopy, and how these are affected by environmental conditions. When MRSA divides in the presence of antibiotics it employs an alternate mode of division, without its characteristic septal rings created by PBP1. Instead, PBP2a is used to form the septum as a dense mesh. From this emerges the question - is this alternate division mode possible to be triggered not just genetically, but through environmental or chemical changes? It was found that in the mutants of PBP1* and PBP1ΔPASTA, a reduction of temperature from 37℃ to 25℃ drastically increased their viability. This poster shows the architecture of the PBP1ΔPASTA mutant when grown at 25℃ and how this changes throughout its division cycle. It is hoped that by understanding how these mutants behave in various conditions, a new weakness in the defence of bacteria may be identified.

68. Single-photon switch for quantum technologies

Mateusz Duda, Physics and Astronomy, 2-3pm

Light is ideal for transferring information over large distances due to its high speed, and is widely used to transfer data in current technology. In emerging quantum technologies, light is also a leading candidate for transferring quantum information, which can be stored in individual photons. In order to construct a quantum network, we therefore need a device that allows us to control the flow of light at the level of single photons, i.e., a single-photon switch. In this work, we present a theoretical proposal for a switch that uses light-matter interactions to control the direction of photon propagation. We quantify the performance of the switch by calculating its efficiency, which is the probability that an input photon will be sent in the desired direction, and its fidelity, which tells us how well the switch preserves the photon state. Our results show that the switch can operate with high efficiency and fidelity, making it a promising device for future quantum technologies.

70. Enabling independent electrical control of two quantum emitters via introducing mid-cavity structural division in photonic crystal microcavities

Monika Singh, Physics and Astronomy, 2-3pm

This study investigates the execution of independent electrical control over two quantum dot emitters within the single photonic crystal microcavities. We accomplish spatial separation of two quantum dots by splitting the cavity by inducing ion beam implantation, which allows for independent tuning without cross-interference. Using photoluminescence and transmission spectroscopy, we investigate the isolated coupling of quantum dots to cavity mode, exhibiting improved light-matter interaction . This unique approach provides a scalable solution for multi-emitter collective coupling in quantum photonic systems, opening the door to deterministic photon emitters with independent control for quantum information processing.

82. Understanding perovskite semiconductor morphology and surface potential at a nano-scale

Rehmat Goodwin, Physics and Astronomy, 3-4pm

Perovskite materials have significant potential for next-gen optoelectronics, due to their excellent optoelectronic properties and tuneable band gap. Due to the fabrication routes employed for these semiconductors, heterogeneities are introduced on multiple length scales. These have been shown to influence the stability of perovskite optoelectronic devices. Understanding heterogeneity on multiple length scales is critical to understanding the links between structure and device instability. In this work we use Kelvin Probe Force Microscopy (KPFM) to image the charge transport mechanisms of perovskite thin films with relation to their topography. This allows us to develop a picture of heterogeneity at the nano-scale which we then correlate with the chemistry of our materials. The results provide valuable insights into charge dynamics and give a promising indication of how KPFM can be utilised as a characterisation technique in the field.

88. JWST Observations of Auroral Brown Dwarf

Eleanor Pike, Physics and Astronomy, 3-4pm

Aurorae (e.g. the Northern Lights) are not unique to Earth. We see these 'light shows' on almost all of our planets, and beyond our Solar System on objects known as brown dwarfs: too massive to be exoplanets but too cool to be stars. In 2015, LSR J1835+3259 was the first brown dwarf to have confirmed aurora with its simultaneous optical and radio variations. NASA's James Webb Space Telescope has since allowed us to observe at IR wavelengths in unprecedented detail. IR studies of LSR J1835 have revealed 1) it is likely older than suspected, 2) the variability in flux has decreased since previous aurorae observations, and 3) the previous model of variability doesn't work. I therefore present a new model for the variability. I find that between light scattering off radiation belts, dust from an exoplanet companion, and heating/disequilibrium chemistry due the auroral processes, the latter is most likely to physically explain this new model.

97. Quasicrystals in Coaxial Cable Networks

Benjamin Kinvig, Physics and Astronomy, 3-4pm

Coaxial cables can be used to create networks representing molecules and lattice structures, such as benzene and graphene. In these networks the junctions between cables act as atoms, and the cables as bonds. The resonance frequencies of the network then correspond to the energies of the states in the actual structure. This gives a simple and easy platform with which to study condensed matter systems and look at their properties when disorder is introduced in a controlled way. The main system of interest here will be one dimensional quasicrystal structures, which display an array of interesting properties, such as super band gaps and unusual localisation properties. These quasicrystals are designed using a simple set of rules, connected to Fibonacci sequences. We discuss using coaxial networks to investigate the properties of quasi-periodic systems, contrasting them with periodic and random structures.

101. Learning the equations that govern collective motility in Pseudomonas aeruginosa colonies

Tanju Cakar, Physics and Astronomy, 3-4pm

Some bacteria self-organise into turbulent flows via self-motility and cell-to-cell collisions, known as active turbulence. A key challenge to our understanding of active turbulence is mapping experimental data to mathematical models. Physics-inspired approaches to modelling typically start from known first principles to construct minimal models. In biology, diversity and complexity is the rule, not the exception, so modellers need to account for how different factors we observe, such as the shape and speed of cells, can be reflected in models to improve the fit to data. New machine learning methods have opened up the possibility of an alternative approach to model building, by selecting the best fitting model algorithmically, while using human-inputted constraints to improve model discovery. We apply a machine learning-based method for learning equations to experimental data of active turbulence in wild and mutant Pseudomonas aeruginosa, comparing the learned models for both strains.

106. Design, build and use of a light-sheet microscope for automated imaging of zebrafish neurological disease models

Ethan Giles, Physics and Astronomy, 3-4pm

Development of a medium to high throughput light-sheet fluorescent microscope including two wavelengths, 488nm(green) and 561nm (red). This lightsheet will be used in tandem with a zebrafish sorting robot that will collect individual fish from a 96 well plate and place them into the FOV of the light-sheet system, allowing for precision positioning of the zebrafish with high repeatability, and higher throughput of individual zebrafish samples. The lightsheet will be formed using 2 galvanometer scanning mirrors which are rapidly scanned along the Y plane, and the creation of a 3 dimensional image is done using a slower scan in the Z plane. An electrically tunable lens will be used to account for the focal point changes as the laser is scanned through the zebrafish sample. Once the two systems have been joined, I will use the system for drug screenings, specifically for Schwann cell recovery in the PNS due to mutations in the Adgrg6 protein.

110. Controlling Environmental Interactions for Solid-State Quantum Technologies

Toby Rawlings, Physics and Astronomy, 3-4pm

Quantum technologies promise to deliver numerous benefits and revolutionise the way we process and share information. Whilst the theoretical background is well understood, it remains challenging to realise quantum information processing systems in reality. This is primarily due to the issue of dephasing, whereby a quantum state loses its coherence through interactions with its macroscopic environment. This work focuses on the interactions between quantum dots - a promising platform for quantum information processing - and their environment, including spectral diffusion and phonon coupling.

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