IPOE 2026 Detailed Program

It is now possible to simulate the structure and dynamics with of mixed ionic and electronic conductors (OMIEC) by combining classical molecular dynamics and quantum chemical methods. The coupled dynamics of excess charges and nuclei is naturally included in the description and the methodology is scalable for the exploration of multiple chemistry. A key observation from these studies is an unexpected dynamical effect. The energy of the localized carrier states evolves in time with characteristic timescale of 5-500 ps, due to the conformational flexibility of the polymer and the interaction with the ions. The ionic and nuclear dynamics are driving the electronic dynamics rather than providing a static disordered landscape. As a consequence, large mobilities are possible also in the presence of very large disorders. A numerical model is derived to quantify the mobility enhancement due to the dynamic disorder and to link more transparently the physics of electronic transport in OMIEC with that of the most conventional “dry” semiconductors. The combination of brute force and reduced model is particularly powerful. Details models help exploring the details of the interactions between materials and biological environments while reduced models can be used to derive broader design rules. We show for example how there is an optimal bandwidth to maximize the charge mobility in organic semiconductors.

Heat conduction is a crucial process for all applications in which excess heat needs to be either dissipated or supplied. In electrically insulating materials, heat transport can either be described in real space via the motion of atoms or in reciprocal space via the transport of phonons. To develop reliable structure-to-property relations for the thermal conductivity of complex materials, an atomistic understanding of the underlying processes is crucial. This understanding can be achieved via atomistic computer simulations provided that they yield quantitatively accurate results.
To achieve that, a highly accurate and at the same time extremely efficient description of inter-atomic interactions is required: as density functional theory (DFT) is far too inefficient for solving the Kohn-Sham equations millions of times for tens of thousands of atoms, and as classical force fields are far too inaccurate, system-specifically machine-learned force fields appear as the ideal choice. We applied so-called moment-tensor potentials trained via a specially adapted active learning approach,1,2 reaching essentially DFT accuracy for various physical observables with a maximum estimated speedup of eleven orders of magnitude. These potentials can then be combined with methods operating in real space (analyzing particle trajectories)1,3 and in reciprocal space (relying on phonon properties),5-7 yielding a quantitative agreement with accurate experiments (often on single crystals).
As far as physical insights are concerned, for example, the analysis of the real-space effective temperature distribution in MOFs subject to a thermal gradient allows the identification of local heat-transfer bottlenecks;3 in contrast, analyzing the dynamics of phonons reveals the actual heat-transport mechanism, showing that not only the particle-like motion of phonons, but also their tunneling becomes highly relevant.4 Interestingly, it turns out that different ranges of phonons dominate different transport mechanisms.6 Finally, changes in phonon properties explain why in molecular crystals like naphthalene the thermal conductivity increases by about an order of magnitude at elevated pressures of ~6 GPa.7

References:
[1] Sandro Wieser and Egbert Zojer, npj Comput. Mater., 2024, 10, 18
[2] Lukas Reicht, Lukas Legenstein, Sandro Wieser, and Egbert Zojer, Molecules, 2024, 29, 3724
[3] Sandro Wieser, Tomas Kamencek, Johannes P. Dürholt, Rochus Schmid, Natalia Bedoya-Martínez, Egbert Zojer, Adv. Theory Simul., 2021, 4, 2000211
[4] Lukas Legenstein, Lukas Reicht, Sandro Wieser, Michele Simoncelli, Egbert Zojer, npj Comput. Mater., 2025, 11, 29
[5] Lukas Reicht, Lukas Legenstein, Sandro Wieser, Egbert Zojer, npj Comput. Mater., 2026, 12, 129
[6] Florian P. Lindner, Marco Moser, Lukas Legenstein, Sandro Wieser, Egbert Zojer, submitted.
[7] Lukas Legenstein, Sandro Wieser, Michele Simoncelli, and Egbert Zojer, in preparation.

Titles of the posters with each name

The presentation will review our recent collaborative work. Stable perovskite solar cells (PSCs) under operation were early demonstrated using 2D multilayered perovskite phases [1,2]. 3D perovskites are more promising in terms of high photoconversion efficiencies. Exploring the combination of 2D and 3D perovskites in PSC architectures is a joint project that started more recently. When combined in 2D/3D bilayer stacks using new versatile growth methods based on solvent engineering, excellent PSCs device stability can be achieved [3]. Besides solvent engineering, a deep understanding of electronic properties, including band alignment is required to properly choose each of the 2D and 3D layer compositions [4]. In addition, related work on 3D perovskite solar cells clearly demonstrated that strain management in the structure is key towards better stability under operation [5, 6]. Further improvements was achieved based on the concept of lattice matching [7], which relies on mechanical energy considerations to select the best pair of 2D/3D or more generally perovskite/perovskite combination. In 2024, it led to record stability for pure FAPbI3 based PSCs [8]. Very recently, this stability was further improved by preventing the degradation pathway from 3C-FAPbI3 to 2H-PbI2 thanks to a Cl-based additive [9]. Instead, it undergoes degradation only upon exposure to harsh conditions such as 15-sun illumination and 90°C through the energetically 3R-PbI2 phase path. These approaches are currently extended to combine more than a pair of perovskite layers of any type (3D, 2D, 1D, 0D…) and into solution-processed photoactive heterostructures to further improve stability, without compromising efficiency, in n-i-p or p-i-n PSC architectures, as well as for other optoelectronic devices.

References:
[1] H. Tsai et al, Nature, 2016, 536, 312.
[2] J. C. Blancon et al, Science, 2017, 355, 1288.
[3] S. Sidhik et al, Science, 2022, 377, 1425.
[4] B. Traore, ACS Energy Lett., 2022, 7, 349.
[5] W. Nie et al, Nature Comm., 2016, 7, 11574.
[6] H. Tsai et al, Science, 2018, 360, 67.
[7] M. Kepenekian et al, Nano Letters, 2018, 18, 5603.
[8] S. Sidhik et al, Science, 2024, 377, 1425.
[9] R. Garai et al, Science, 2026, 392, DOI: 10.1126/science.aeb7992

Two-dimensional (2D) materials have emerged as promising candidates for the Internet of Things (IoTs) and next-generation wearable electronics, owing to their exceptional properties and compatibility with solution- processed approaches, hence enabling the use of simple and cost-effective techniques – such as inkjet printing – for fabrication of flexible devices.
In this talk, I will present the development of biocompatible, water-based inks of conducting, semiconducting, and insulating 2D materials [1-2], based on the supramolecular chemistry approach that enables simultaneous exfoliation and functionalization of nanosheets, allowing to produce 2D materials with tailored surface chemistries, specifically designed for sensing and biomedical applications [3-4]. I will discuss fully printed photodetectors [2,5], memristors [6-7], and diodes [8] made onto paper. Finally, I will present the first flexible and fully solution processed 2D material transistor operating without ion-liquid gating. [9]

References:
[1] Parvez, Casiraghi, Acc. Chem. Res. 58, 2, 189–198 (2025);
[2] McManus et al, Nature Nano, 12, 343 (2017);
[3] Chen et al, Advanced Materials 36 (18), 2312621 (2024);
[4] Shin et al, Nanoscale 12 (23), 12383-12394 (2020);
[5] Zhao et al, under review;
[6] Peng et al, Materials Horiz. (2023), DOI: 10.1039/D3MH01224G;
[7] Xiao et al, Nature Comm. 15 (1), 10591 (2024);
[8] Grillo et al, ACS Nano, 9 (34), 30833 (2025);
[9] Chen et al, Small, accepted

Molecular functionalization has become a central strategy in organic and hybrid electronics, enabling the tuning of charge injection and dielectric environment through the chemical versatility of molecular systems. In recent years, these concepts have also been extended to 2D materials, where molecular species have been employed to tailor electronic and optoelectronic behavior. However, since these strategies rely on surface modification, their impact is often limited to exposed surfaces and ultrathin flakes.
Molecular intercalation offers an attractive alternative by inserting functional species directly within the van der Waals gaps of layered materials, creating buried organic/inorganic interfaces throughout the crystal volume. This approach enables the formation of hybrid superlattices in which molecular functionalities can directly tailor the intrinsic physical properties of bulk crystals. Despite this potential, molecular intercalation in 2D materials remains comparatively underdeveloped, largely because conventional methods often degrade crystalline quality and are difficult to apply to nanodevices.
Here we introduce a galvanic intercalation strategy that exploits the low reduction potentials of selected metals to drive the insertion of molecular cations under mild conditions.[1] The method enables the incorporation of a broad range of functional species—including organometallic complexes and chiral molecules—into both bulk crystals and few-layer flakes of vdW materials. Using this platform, we investigate how molecular intercalation modifies the electronic transport of the van der Waals superconductors NbSe2 and TaS2 within the same few-layer devices before and after intercalation.[2]
In parallel, the galvanic approach enables the fabrication of more complex hybrid architectures, including vertical intercalation heterostructures in which molecules are selectively confined to one component of a van der Waals stack, and lateral heterostructures where different molecular species occupy neighbouring regions of the same flake. Finally, we show that these intercalated materials can be integrated into superconducting devices,[1] highlighting galvanic molecular intercalation as a versatile platform to engineer hybrid functionalities and emergent electronic states in 2D materials.

References:
[1] D. Tezze et al., Nature Synthesis, 2026, 5, 388.
[2] D. Margineda et al., Advanced Functional Materials, 2026, 36, e27724.

Electrolyte-gated organic field-effect transistors (EGOFETs) are emerging as powerful, ultrasensitive, label-free biosensors due to their low cost, straightforward electrical readout, and inherent signal amplification. Their operation is based on the formation of two electrical double layers (EDLs) at the organic semiconductor–electrolyte and electrolyte–gate interfaces when a gate voltage is applied. This interaction modulates charge transport along the organic semiconductor, rendering EGOFETs highly responsive to interfacial changes—a property extensively harnessed in biosensor development.
A common approach for biosensor fabrication involves the biofunctionalization of the gate electrode using antibody or aptamer immobilization strategies. Such methodologies have enabled the detection of biologically relevant molecules at ultra-low concentrations, positioning EGOFETs as promising candidates for next-generation point-of-care (PoC) diagnostics. For instance, in our group, we have leveraged this platform to detect alpha-synuclein, a biomarker of Parkinson’s disease and to monitor the aggregation kinetics of beta-amyloids [1–2].
Despite their diagnostic potential, the portability of EGOFET-based assays is often hindered by limited microfluidic integration and labor-intensive, multi-step protocols. To overcome these limitations, we present a simplified EGOFET integrated with lateral flow paper fluidics, enabling a reusable, compact, and cost-effective PoC test with rapid turnaround (~30 minutes). This platform was validated for the detection of Human Immunoglobulin G and to detect Hepatitis B/C biomarkers, demonstrating a broad linear range, high selectivity, reproducibility, and very low limit of detection [3-4].

[1] S. Ricci, S. Casalini, V. Parkula, M. Selvaraj, G. D. Saygin, P. Greco, F. Biscarini, M. Mas-Torrent, Biosensors and Bioelectronics, 2020, 167, 112433.
[2] S. Ruiz-Molina, C. Martinez-Domingo, S. Ricci, S. Casalini, Marta Mas-Torrent, ACS Appl. Electron. Mater.,2024, 12, 8998.
[3] M. J. Ortiz-Aguayo, C. Martinez-Domingo, D. Gutierrez, D. Kos, M. Mas-Torrent, Adv. Mater., 2025, e13468.
[4] M. J. Ortiz-Aguayo, C. Martinez-Domingo, D. Gutierrez, M. Mas-Torrent, Biosensors and Bioelectronics, 2026, in press.

Organic mixed ionic–electronic conductors (OMIECs) are promising materials for bioelectronics and electrochemical sensing due to their ability to couple ionic and electronic charge transport at low operating voltages. Realizing fully passive and battery-free sensor systems based on OMIECs, however, requires understanding the fundamental limits of signal propagation and energy dissipa-tion in these materials.
Here, we first investigate dissipative charge transport in OMIEC channels using electrical phase velocity measurements and modulated electrochemical atomic force microscopy.[1] Interpreting the results within a transmission line framework reveals that energy dissipation is governed by the ratio between electronic mobility and volumetric capacitance, establishing a key figure of merit for OMIEC materials beyond transistor amplification.
Building on this understanding, we demonstrate a fully passive oxygen sensor based on an or-ganic electrochemical transistor (OECT).[2] By combining optimized device geometries with near-field communication (NFC) power harvesting, the system enables wireless and battery-free oxygen sensing in air and water. The interrogating NFC field is sufficient to power the electronics, acquire the sensor signal, and transmit the data wirelessly.
These results connect microscopic transport physics with the development of sustainable, ultra-low-power sensing systems based on OMIEC materials.

References:
[1] F. Bonafè, M. Bazzani, B. Fraboni, T. Cramer, Nature Communications 16, 2499 (2025); doi: 10.1038/s41467-025-57528-9
[2] L. G. D'Amico et al., Advanced Materials Technologies 10, 2401875 (2025); doi: 10.1002/admt.202401875

Organic Field-Effect Transistors (OFETs) have emerged as versatile transduction platforms for biochemical sensing, owing to their mechanical flexibility, low-cost fabrication, and compatibility with large-area processing. A particularly attractive configuration couples the transistor with a physically separated sensing surface acting as an extended gate (ExG): this solution has recently showed very interesting performances for ion sensing [1]. Beside the intrinsic signal amplification, the main advantage of ExG-OFETs is the possibility of selectively functionalizing the ExG area without directly exposing the organic semiconductor to the biological environment, thus improving shelf life and operational stability. In this work, we present an ExG-OFET platform in which the interface properties of the sensing electrode are
engineered to achieve selective biochemical detection. The sensing unit consists of a gold extended-gate electrode functionalized with thiolated DNA aptamers via a controlled self-assembly protocol. Target binding at the gold/aptamer/electrolyte interface induces a conformational change in the aptamer structure and charge distribution, modulating the surface potential and producing a measurable shift in the OFET drain current. This transduction mechanism places interface engineering at the core of device performance, making the platform directly relevant to the study of interface properties in organic electronics.
As a demonstrative application, the platform was employed for cortisol detection in buffer solution, a relevant stress biomarker present in biofluids such as sweat [2]. A systematic comparison between a short (14-mer) and a long (61-mer) thiolated aptamer sequence revealed that aptamer length is a critical design parameter: in particular, the long aptamer yielded a clear, reproducible, concentration-dependent current modulation across a pM–μM range. These results point to aptamer length as a key factor governing charge coupling efficiency at the bioelectronic interface. Stability measurements performed in pure buffer confirmed negligible drift, validating the robustness of the functionalization protocol. Complementary surface characterization via Surface Plasmon Resonance (SPR) is currently underway to provide independent validation of aptamer binding and surface coverage, further corroborating the interface-level interpretation of the electrical response.
The modularity of the ExG-OFET architecture — where the sensing surface can in principle be functionalized with bioreceptors targeting diverse analytes — positions this platform as a generalpurpose tool for label-free biochemical detection. Potential applications include wearable and point-of-care devices for continuous monitoring of biomarkers in sweat and other biofluids.

References:
[1] Viola et al., https://doi.org/10.1016/j.snr.2025.100340
[2] Sheibani et al., https://doi.org/10.1038/s43246-020-00114-x

Polarons form when injected charges strongly couple to molecular vibrations in organic semiconductors, directly influencing charge transport and device operation. In organic electrochemical devices, such as organic electrochemical transistors (OECTs) and organic synaptic transistors (OSTs), ions further drive polaron formation, structural deformation, and charge localisation/delocalisation. However, direct in situ evidence linking ion-induced polarons to molecular structural changes and device function remains limited. In this talk, I will present our recent spectroscopic studies of conjugated polymers under electrochemical doping and gate-pulse operation. I will show how subtle side-chain changes, including alkyl/glycol chemistry and side-chain density, regulate polaron formation; how backbone extension modifies polaron delocalisation and transport; and how molecular structure controls ion retention during synaptic gate-voltage pulses. These results provide direct evidence of ion-coupled polaron formation and reveal how electron-phonon coupling governs charge transport, structural response, and memory behaviour in organic electrochemical devices.

References:
[1] Stewart, K., et al., “Polarons in DPP Polymers - How Glycol Side Chains and Elongated Conjugated Backbone Influence the Formation and Transport.” Advanced Electronic Materials (2026) 12(7). doi:10.1002/aelm.202500731
[2] Stewart, K. et al., “Understanding Effects of Alkyl Side Chain Density on Polaron Formation via Electrochemical Doping in Thiophene Polymers”, Advanced Materials (2024) 36(20). doi:10.1002/adma.202211184
[3] Tan, E. et al., “The Role of Long-Alkyl-Group Spacers in Glycolated Copolymers for High-Performance Organic Electrochemical Transistors”. ADVANCED MATERIALS (2022) 34(27). doi:10.1002/adma.202202574