AFM 2022: The 4th Conference on Advanced Functional Materials      29-31 August

Professor Katan's web page

Metal halide perovskites and their interfaces: current issues and recent advances 

Claudine Katan
Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), France

The considerable attention paid to metal halide perovskites (MHP) in recent years led to several scientific and technological advances, among which the creation of a new photovoltaic (PV) technology that competes with the most widespread ones1. With the ever-increasing diversity of applications explored, the need for fundamental understanding persists and may be gained either by smart and simple experimental protocols or models, or else via complex set-ups and computationally expensive ab-initio calculations.

At present, MHP materials used in devices are frequently far from their ideal bulk structure, which hinders the use of state-of-the-art first principles simulations including many-body effects and calls for the design of dedicated models. For PV and LEDs, they are mixed with each other in complex alloys and heterostructures, including 2D/3D compositions, combined with additives or protecting layers to improve their stability and/or defectiveness as well as assembled with carrier selective layers. On the other hand, colloidal MHP nanocrystals are promising for devices exploiting both weak and strong light-matter interactions, such as lasers, single photon emitters if not all-optical logic gates. 

After a general introduction on MHPs, the talk will bring up some of the hot topics in the field and will summarize recent results obtained by the group in Rennes in collaboration with our partners from France and abroad2-6. 

Acknowledgements:
This research received funding from the European Union’s Horizon 2020 research and innovation program, through an Innovation Action under the grant agreement No. 861985 (PeroCUBE) and a FET Open action under the grant agreement No. 899141 (PoLLoC). 

References

_{[1] https://www.nrel.gov/pv/cell-efficiency.html and https://www.nrel.gov/pv/module-efficiency.html.
[2] W. Li et al., Light-activated interlayer contraction in two-dimensional perovskites for high-efficiency solar cells, Nature Nanotechnology, 17, 45 (2022)
[3] B. Traore et al., A theoretical framework for microscopic surface and interface dipoles, work functions and valence band alignments in 2D and 3D halide perovskite heterostructures, ACS Energy Lett. 7, 349 (2022) 
[4] B. Traore et al., Band gap and energy level alignment of 2D and 3D halide perovskites using DFT-1/2, Phys. Rev. Materials, 6, 014604 (2022)
[5] S. Sidhik et al., Deterministic fabrication of 3D|2D 1 perovskite bilayer 2 stacks for durable and efficient solar cells, accepted.  
[6] Q. Akkerman, et al., Taming the nucleation and growth kinetics of lead halide perovskite quantum dots, https://doi.org/10.21203/rs.3.rs-1236393/v1}

Professor Facchetti's web page

Unconventional film morphologies for stretchable electrochemical transistors

¹ Northwestern University 2145 Sheridan Road, Evanston IL, 60208 USA 
*Email: a-facchetti@northwestern.edu

Abstract

The realization of fully stretchable electronic materials is central to advancing new types of mechanically agile and skin-integrable optoelectronic device technologies. In this presentation we report a materials design concept combining a porous organic semiconductor honeycomb film morphology with a biaxially pre-stretched platform that enables high-performance organic electrochemical transistors (OECTs) with charge transport stability up to 30-140% tensional strain, limited only by metal contact fatigue. The pre-stretched honeycomb channel semiconductor, donor-acceptor polymer DPP-g2T (DPP=diketopyrrolopyrrole, 2T=dithiophene), exhibits high ion uptake with ultra-stable electrochemical and mechanical properties, > 1500 redox cycles with 10000 stretching cycles under 30% strain. Highly reliable electrocardiogram recording cycles and synapse responses under varying strains, along with mechanical finite element analysis, underscore that the present stretchable OECT design strategy is suitable for diverse applications requiring stable signal output under deformation with low power dissipation and robustness to mechanical deformation.

Reference

<sub>1. Chen, J.; Huang, W.; Zheng, D.; Xie, Z.; Zhuang, X.; Zhao, D.; Chen, Y.; Su, N.; Chen, H.; Pankow, R. M.; Gao, Z.; Yu, J. Guo, X.; Cheng, Y.; Strzalka, J.; Yu, X.; Marks, T. J.; Facchetti, A. Highly-Stretchable Organic Electrochemical Transistors with Strain-Resistant Performance Nature. Mater. 2022, 21, 564–571.
2. Huang, L.; Wang, Z.; Chen, J.; Wang, B.; Chen, Y.; Huang, W.; Chi, L.; Marks, T. J.; Facchetti, A. Porous Semiconducting Polymers Enable High-Performance Electrochemical Transistors. Adv. Mater. (Weinheim, Ger.) 2021, 33(14), 2007041.</sub>

Author introduction

Professor Bilek's web page

Tailorable biosignalling interfaces for controlled modulation of cell and tissue responses on glassware, multi-well plates, porous 3D scaffolds and micro/nanoparticles 

MMM Bilek*^1,2,3,4, C.T. Tran^1,2, A. Gilmour^1,2, B Akhavan^1,2, L Haidar^1,2, R. Walia^1,2, K Sato⁵, X. Feng², S Wickham^1,5, A Waterhouse³, G Yeo³, S Fraser<sup>2

1</sup>School of Physics, A28, University of Sydney, NSW 2006, Australia
²School of Biomedical Engineering, University of Sydney, NSW 2006, Australia
³Charles Perkins Centre, University of Sydney, NSW 2006, Australia
⁴ Sydney Nano Institute, University of Sydney, NSW 2006, Australia
⁵School of Chemistry, University of Sydney, NSW 2006, Australia

Modern biomedical research and clinical practice relies on a wide range of materials formed into complex structures to provide suitable environments for cells and tissues. These materials range from metals and glasses to plastics and hydrogels. Constraints on mechanical and optical properties required for particular in-vivo and in-vitro applications are usually not compatible with providing the optimum biological microenvironments for the interfacing cell types. 

Here we describe rapid, wet-chemistry free approaches that utilise environmentally-friendly ionised gases to activate a range of materials and structures for spontaneous, reagent-free, covalent functionalisation with bioactive molecules. Molecules that can be immobilised whilst retaining their functions include but are not limited to oligonucleotides, enzymes, peptides, aptamers, cytokines, antibodies, cell-adhesion extra-cellular matrix molecules and histological dyes. Their immobilisation occurs via surface-embedded radicals that are created by energetic ions from the ionised gas bombarding the materials surfaces prior to contact with the biomolecules [1]. Typical time scales of cell cultures necessitate covalent tethering because physical bonding would be susceptible to exchange with biomolecules from the culture media and robust spatial patterning of the molecules is required to replicate physiologically relevant structures. 

This presentation will examine the fundamental science and process adaptions that enable such surface modifications to be applied to the internal surfaces of multi-well plates, complex, porous materials and micro/nanostructures whilst retaining favourable optical properties. Strategies to pattern immobilised molecules on the surfaces will be examined. Applications enabling biological studies of the response of individual cells to proteins on a sub-cellular scale [3], and the preparation of multi-functionalisable nanoparticles [4] will be discussed. The surface embedded radicals are shown to enable polymerisation of hydrogels from thus activated surfaces [5] and control of the density and orientation of surface-immobilised bioactive peptides through pH variations and/or the application of external electric fields during the immobilization [6]. 

_{[1] PNAS  108:14405-14410  (2011); 
[2] ACS Appl. Mater. and Interfaces (2018); 
[3] ACS Appl. Nano Materials (2018); 
[4] Adv. Funct. Materials (2020);
[5] Nat. Comm. 9:357 (2018)} 

Professor Ramanath's web page

Molecular-design of inorganic interfaces and nanomaterials

Ganpati Ramanath
John Tod Horton Professor of Engineering
Department of Materials Science and Engineering
Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
Visiting Professor
Advanced Functional Materials Laboratory, Department of Physics, Chemistry and Biology, 
Linköping University, Sweden

Engineering nanomaterials and their heterointerfaces with control over multiple properties is crucial for diverse applications. I will first discuss a new approach to create high-figure-of-merit thermoelectric nanomaterials from nanocrystals synthesized by molecularly-directed synthesis and doping. The nanostructuring-doping combination in bulk nanostructured pellets formed from doped nanocrystals allows the untangling of unfavorable couplings between multiple properties. Doping-induced alterations in defect chemistry and electronic band structure provide a means to simultaneously achieving a high electrical conductivity and a high Seebeck coefficient, while nanostructuring leads to low thermal conductivities. I will then describe the use of molecular nanolayers at inorganic interfaces to obtain multifold enhancements in chemical stability, interfacial fracture energy, and thermal and electronic transport. Mechanisms include strong bonding, diffusion curtailment, and altered interfacial phase formation paths, that can be controlled through choices of molecular termini, chain length and backbone structure, and annealing. I will show that molecular nanolayers can trigger unusual interfacial phenomena (e.g., viscoelastic bandgaps), provide a new approach for studying interfacial fracture nanomechanics through macroscale experiments, and enable the design of high-interface-fraction organic-inorganic nanocomposites wherein the molecularly-induced interface properties become the materials properties. 

Selected references

_{Sci. Rep. 12, 10788 (2022); Nature Comm. 9, 5249 (2018); ACS Appl. Mater. Interf. 9, 2001 (2017); ACS Appl. Mater. Interf. 8, 4275 (2016); Adv. Mater. 28, 6436 (2016); Nature Mater. 12, 118 (2013); Nature Mater. 11, 233 (2012); Nano Lett. 12, 4523 (2012); Nano Lett. 11, 4337 (2011); ACS Nano 4, 5055 (2010); Nano Lett. 10, 4417 (2010); Nature 447, 299 (2007); Appl. Phys. Lett. 104, 053903 (2014); Adv. Mater. Interf. 2, 1500186 (2015); Nanotechnology 27, 175601 (2016); Scripta Mater. 121, 42 (2016); Appl. Phys. Lett. 109, 173904 (2016).} 

Professor Dubrovinskaia's web page

Research on Advanced Functional Materials at High Pressures

Material Physics and Technology at Extreme Conditions, Universität Bayreuth, Germany
Guest Professor at Linköpings Universität, Sweden
E-mail: Natalia.Dubrovinskaia@uni-bayreuth.de

Abstract

The state of matter is strongly affected by variations in its chemical composition and the external parameters, such as pressure and temperature, allowing tuning of materials properties. This gives rise to a variety of phenomena relevant for a broad range of scientific disciplines and technological applications, from fundamental understanding of the Universe to targeted design of advanced materials. Compression is known to endorse, for example, metal-to-insulator transitions, superconductivity, and other interesting phenomena. To generate very high static pressures, we use an instrument which is called a diamond anvil cell (DAC), in which the material under investigation is squeezed between very small flat tips of two gem quality diamonds – diamond anvils. Due to extremely high compressional strength of diamond, pressures up to 200 GPa can be achieved on the sample. Our group has extended the static pressure range for materials investigations up to 1TPa (10 million atmospheres) due to our invention of a double-stage DAC. 
In our research at high and ultra-high pressures, we not only synthesize novel, often unpredictable, materials and study their structures using synchrotron single-crystal X-ray diffraction, but also try to understand the physical phenomena underlying their formation, chemical bonding, and properties.  In this talk I will focus on recent results achieved in a very close collaboration with Professor Igor Abrikosov and his theoretical group at Linköpings Universität. In particular, the synthesis and characterisation of a Dirac material (layered van der Waals bonded BeN₄ polymorph) and a whole plethora of novel transition metals borides, nitrides and polynitrides, including metal-inorganic frameworks Hf₄N₂₀⋅N₂, WN₈⋅N₂, and Os₅N₂₈⋅3N₂ with polymeric nitrogen linkers (a new class of compounds featuring open porous structures at megabar compression) will be discussed. Selected references are provided below.
   

Acknowledgments

I thank the Federal Ministry of Education and Research, Germany (Grant No. 05K19WC1), the Deutsche Forschungsgemeinschaft (DFG Projects No. DU 954–11/1) and the Swedish Government Strategic Research Areas in Materials Science on Functional Materials at Linköping University (Faculty Grant SFO-Mat-LiU No. 2009 00971).

Selected references

_{1) L. Dubrovinsky, S. Khandarkhaeva, T. Fedotenko, D. Laniel, M. Bykov, C. Giacobbe, E. L. Bright, P. Sedmak, S. Chariton, V. Prakapenka, A. V. Ponomareva, E. A. Smirnova, Maxim P. Belov, F. Tasnádi, N. Shulumba, F. Trybel, I. A. Abrikosov, N. Dubrovinskaia. Materials synthesis at terapascal static pressures. Nature (2022), 605, 274-278. doi:10.1038/s41586-022-04550-2
2) A. Aslandukov, F. Trybel, A. Aslandukova, D. Laniel, T. Fedotenko, S. Khandarkhaeva, G. Aprilis, C. Giacobbe, E.L. Bright, I. A. Abrikosov, L. Dubrovinsky, N. Dubrovinskaia. Anionic N18 Macrocycles and a Polynitrogen Double Helix in Novel Yttrium Polynitrides YN6 and Y2N11 at 100 GPa. Angewandte Chemie International Edition (2022), in press.
3) E. Bykova, E. Johansson, M. Bykov, S. Chariton, H. Fei, S.V. Ovsyannikov, A. Aslandukova, S. Gabel, H. Holz, B. Merle, B. Alling, I.A. Abrikosov, J.S. Smith, V.B. Prakapenka, T. Katsura, N. Dubrovinskaia, A.F. Goncharov, L. Dubrovinsky. Novel Class of Rhenium Borides Based on Hexagonal Boron Networks Interconnected by Short B2 Dumbbells. Special edition of the Journal of Materials Chemistry A “Emerging investigators” (2022), in press.
4) M. Bykov, T. Fedotenko, S. Chariton, D. Laniel, K. Glazyrin, M. Hanfland, J. S. Smith, V. B. Prakapenka, M. F. Mahmood, A. F. Goncharov, Alena V. Ponomareva, Ferenc Tasnádi, A. I. Abrikosov, T. B. Masood, I. Hotz, A. N. Rudenko, M. I. Katsnelson, N. Dubrovinskaia, L. Dubrovinsky, I. A. Abrikosov: High-Pressure Synthesis of Dirac Materials: Layered van der Waals Bonded BeN₄ Polymorph. Physical Review Letters, 126 (2021). doi:10.1103/PhysRevLett.126.175501
5) M. Bykov, S. Chariton, E. Bykova, S. Khandarkhaeva, T. Fedotenko, A. V. Ponomareva, J. Tidholm, F. Tasnádi, I. A. Abrikosov, P. Sedmak, V. Prakapenka, M. Hanfland, H.-P. Liermann, M. Mahmood, A. F. Goncharov, N. Dubrovinskaia, L. Dubrovinsky. High-Pressure Synthesis of Metal-Inorganic Frameworks Hf₄N₂₀⋅N₂, WN₈⋅N₂, and Os₅N₂₈⋅3N₂ with Polymeric Nitrogen Linkers. Angewandte Chemie International Edition, 59 (2020). - S. 10321-10326, doi:10.1002/anie.202002487.
6) M. Bykov, S. Chariton, H. Fei, T. Fedotenko, G. Aprilis, A. V. Ponomareva, F. Tasnádi, I. A. Abrikosov, B. Merle, P. Feldner, S. Vogel, W. Schnick, V. B. Prakapenka, E. Greenberg, M. Hanfland, A. Pakhomova, H.-P. Liermann, T. Katsura, N. Dubrovinskaia, L. Dubrovinsky. High-pressure synthesis of ultraincompressible hard rhenium nitride pernitride Re₂(N₂)(N)₂ stable at ambient conditions. Nature Communications, 10 (2019). doi:10.1038/s41467-019-10995-3}

Professor Schubert's web page

"Oxide based high power electronic materials research for the future of green energy"

Professor Furo's web page

NMR Spectroscopic Approaches to Materials. A Case Study in Batteries and Supercapacitors

_{István Furó and Sergey V. Dvinskikh
Department of Chemistry, KTH Royal Institute of Technology, Stockholm, Sweden}
Contact: furo@kth.se, sergeid@kth.se

Last year, the Swedish Research Council VR granted a new national infrastructure SwedNMR. Distributed over nine Swedish universities, the network is tasked by facilitating and broadening access to NMR spectroscopy. One of the three access nodes (located jointly at Stockholm University and KTH Royal Institute of Technology) handles applications of NMR to materials while the other nodes concern biomolecular and medical applications such NMR-based metabolomics. 

Arguably, NMR in materials is an extremely heterogeneous area and, perhaps by tradition, material scientists are not the most ardent users of this methodology. In this lecture we wish to highlight the ways the rich variety of NMR-based experiments can be applied to materials. We shall also illustrate the potential and comparative advantage with NMR that can be realized despite its disadvantages (among other things, its low signal strength and its interpretational pitfalls primarily connected to its tendency to make structural information dependent on the dynamical regime).

Our illustrative examples are going to be taken from the family of materials that, when combined into devices like batteries and supercapacitors, permit us to store electric energy. We shall emphasize that in battery and supercapacitor materials NMR approaches adapted to either the electrodes or the electrolyte can provide direct and local structural and dynamical information about the most crucial component in those systems: the ions. As we are also going to show, a lot what can be learned from NMR is not accessible by other methods. In an orthogonal manner, we shall also try to illustrate what possible insights can be gained from different sorts of NMR parameters like chemical shifts and line splittings (chemical/electronic environments and mesoscopic structures), spin relaxation times (local dynamics), self-diffusion and electrokinetic coefficients (long range dynamics of molecules and ions) and, on a distinct manner, by NMR (or, MRI) images.

Professor Heintz's web page

AI - What is it and Why is it important?

Prof Fredrik Heintz

Self driving cars, intelligent robots and computers with superhuman performance in games like Go and Poker was previously science fiction. 
Now they affect the way we work, our everyday activities, and society at large. This talk will give an overview of what AI is, how it can be used to do better science and also some of the likely consequences for society. Be prepared as you may leave the talk with more questions than answers.

Bio:
Professor of Computer Science at Linköping University, where he leads the Reasoning and Learning lab. His research focus is artificial intelligence especially Trustworthy AI and the intersection between machine reasoning and machine learning. Director of the Wallenberg AI and Transformative Technologies Education Development Program (WASP-ED), Director of the Graduate School of the Wallenberg AI, Autonomous Systems and Software Program (WASP), Coordinator of the TAILOR ICT-48 network developing the scientific foundations of Trustworthy AI, and President of the Swedish AI Society. Fellow of the Royal Swedish Academy of Engineering Sciences (IVA).