Advanced Materials WINTER 2021 SPREAD KNOWLEDGE Editorial Spread knowledge A very special year has passed. Covid-19 gave the framework for our professional and private life. This was not always easy, it was not always nice, but it was no stop sign to research. Research has actually gained a lot of visibility. European leaders decided to tackle Covid-19 by listening to scientific advisors, use evidence-based scenario’s, see hypothesis been proven wrong or right and reacting to it. The teams working on Covid-vaccines have made enormous leaps in a short time to provide new, safe vaccines that may help to recover society. This new focus on scientific advice and research solving a problem, may be an enormous opportunity to build on for all scientific disciplines. Science is not a hobby; Colophon it is not just an opinion. Science is ideally balancing existing knowledge, new results, interpretation and Editors critical discussion to a sound consensus. It provides Jan Peter Birkner solutions to complex problems, some of which overseen by the public, some of which at the center of interest. Wherever in this spectrum research on Advanced Photography Materials is, investing in it may be essential already Sylvia Germes in the near future. And spreading the knowledge on what is going on Design in our labs may create ground for the next good to Mónica Espinoza happen. Therefore: stay safe, stay curious, enjoy our stories here, and keep telling your story. Cangahuala Print Ricoh Grafimedia Contact Coordinating Office Nijenborgh 4 Eric Heeres 9747 AG Groningen Director for the Engineering and T: +31 50 363 4922 Technology Institute Groningen W: www.rug.nl/zernike E: [email protected] Adri Minnaard Director of the Stratingh Institute for Chemistry Caspar van der Wal Scientific director Zernike Institute for Advanced Materials 2 ADVANCED MATERIALS | WINTER 2021 In this issue AI reduces computational time required to study fate of molecules exposed to light 4 Combining incipient ferroelectrics and graphene leads to new insights into memristive devices 6 Turning heat into power with efficient organic thermoelectric material 8 Spin-orbit coupling leads to stable spins in color centers in materials 10 New High Speed AFM results featured as Spotlight in JACS 12 Polymer scientists cooperate with industry to create smart materials 14 X-rays reveal in situ crystal growth of lead-free perovskite solar panel materials 16 Spider Silk inspires a new class of synthetic ion-conducting polymers for future energy applications 18 Detailed model important step towards understanding Huntington’s 20 Scientists create coatings from nature 21 Elisabetta Chicca new professor Bio-inspired Circuits & Systems “If we cannot build neural networks, we can’t understand them properly” 22 Simple explanation suffices for conduction in nickelates 24 New assistant professor in our team - Jagoda Sławińska “I think theorists can work more closely with experimentalists” 26 Finding the missing mirror in spintronic nanodevices 28 New pathways with Skyrmion bubbles 29 New model helps to describe defects and errors in quantum computers 30 Transporting energy through a single molecular nanowire 32 Newsflash 33 CogniGron is two years along the path towards ‘human’ computers 34 Virus assembly has been filmed 37 In Focus AI reduces computational time required to study fate of molecules exposed to light by Rene Fransen (ScienceLinX) Light-induced processes are critical in transformative technologies such as solar energy harvesting, as well as in photomedicine and photoresponsive materials. Theoretical studies of the dynamics of photoinduced processes require numerous electronic structure calculations, which are computationally expensive. Scientists from the University of Groningen developed machine learning-based algorithms, which reduce these computations significantly. The Open Source software package that they developed, PySurf, was presented in a paper in the Journal of Chemical Theory and Computation on 24 November. How do molecules behave when for medium-sized molecules, they are exposed to light? typical chromophores have around Knowledge of this process is not thirty heavy atoms.’ Including the only central to crucial processes Our software, influence of the environment at in nature, such as photosynthesis quantum mechanical level on such and vitamin D production, but it is therefore, a system is practically impossible. also critical for the rational design requires several of new molecules with specific ‘Current software searches photoresponsive properties. orders of the entire conformational magnitude less space, but we use machine Machine learning learning to exclude parts of Yet, despite great advances in computational this conformational space hardware and computational search, making it a very smart methods, calculations of the time than existing search,’ Faraji explains. ‘Our interaction between light and direct dynamics software, therefore, requires molecules is still a challenge, several orders of magnitude explains Shirin Faraji, Associate software less computational time than Professor in Theoretical Chemistry, existing direct dynamics software.’ the lead author of the paper. ‘The In the paper, the developers high-level electronic structure report the photodynamics of calculations are already very costly two benchmark molecules, SO2 4 ADVANCED MATERIALS | WINTER 2021 In Focus Representation of machine learning electronic-structure based excited states of a molecule responding to light Illustration: Faraji Lab. and pyrazine, and show that the manual, and Faraji’s team their results are comparable will provide support for users. to those obtained using simulations that are based First release entirely on quantum dynamics. The PySurf software is the result of a project funded by a personal Algorithm grant to Faraji from the Dutch Furthermore, the software Research Council (NWO) Vidi package was developed from programme. Faraji: ‘We are A PhD student scratch and is easy to adapt for only a year and a half into this specific purposes, for example five-year project. So, the current could easily dig by using plug-in and workflow version is just the first release. into the code engines. Faraji: ‘A PhD student We continue to work on the could easily dig into the code program to optimize it and to and develop and develop a specific algorithm, create a user-friendly interface.’ for example a new neural a specific network-based algorithm.’ Reference: Maximilian F. S. J. algorithm, for Menger, Johannes Ehrmaier, Faraji contributed code to and Shirin Faraji: PySurf: example a new several software packages, A Framework for Database neural network- most notably Q-Chem, one of Accelerated Direct Dynamics. the world’s leading quantum J. Chem. Theory Comput. based algorithm. chemistry software programs, online 24 November 2020. and is currently a member of the Q-Chem Board of Directors. This work is part of the The new PySurf package will Innovational Research Incentives interface with Q-Chem, but also Scheme Vidi 2017 with project with other electronic structure number 016.Vidi.189.044, software. PySurf is Open Source, which is (partly) financed by the which means that it is available Dutch Research Council (NWO). as a free download together with UNIVERSITY OF GRONINGEN 5 In Focus Combining incipient ferroelectrics and graphene leads to new insights into memristive devices by Rene Fransen (ScienceLinX) Transistors can have just two values: 0 or 1. Our brains process information via neurons, which are more complicated: they can have any intermediate value, based on the memory of the input they received in the long-term or short-term past. Scientists are trying to build transistors with a similar type memory, called memristors. One interesting material for creating memristive devices is strontium titanium oxide. Scientists from the University of Groningen discovered how this material can change its resistance based on changes in the number of electrons or the accumulation of defects created by the absence of oxygen atoms in the crystal structure. These insights, derived by combining strontium titanium oxide with the 2D material graphene, could lead to the creation of memristors responding at different timescales, corresponding to short-term and long-term memory. Scientists are working on new a great many of these binary materials to create neuromorphic systems, computers can perform computers, with a design based calculations very rapidly. However, on the human brain. A crucial in other respects, computers are component is a memristive device, not very efficient. Our brain uses ... the the resistance of which depends less energy for recognizing faces on the history of the device – or performing other complex tasks combination with just like the response of our than a standard microprocessor. graphene opens neurons depends on previous That is because our brain is made input. Materials scientists from the up of neurons that can have many up a new path University of Groningen analysed values other than 0 and 1 and to memristive the behaviour of strontium because the neurons’ output titanium oxide, a platform material depends on previous input. heterostructures for memristor research and used the 2D material graphene to probe Oxygen vacancies combining it. On 11 November 2020, the To create memristors, switches ferroelectric results were published in the with a memory of past events, journal ACS Applied Materials strontium titanium oxide (STO) materials and 2D and Interfaces. is often used.