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Chirality is a desired property in functional semiconductors for optoelectronic, catalytic, and spintronic applications. Here, introducing enantiomerically-pure 3-aminobutyric acid (3-ABA) into thin films of the 1D semiconductor dimethylammonium lead iodide (DMAPbI3) is found to result in strong circular dichroism (CD) in the optical absorption. X-ray diffraction and grazing incidence small angle X-ray scattering (GISAXS) are applied to gain molecular-scale insights into the chirality transfer mechanism, which is attributed to a chiral surface modification of DMAPbI3 crystallites. This study demonstrates that the CD signal strength can be controlled by the amino-acid content relative to the crystallite surface area. The CD intensity is tuned by the composition of the precursor solution and the spin-coating time, thereby achieving anisotropy factors (gabs) as high as 1.75 × 10–2. Grazing incidence wide angle scattering reveals strong preferential ordering that can be suppressed via tailored synthesis conditions. Different contributions to the chiroptical properties are resolved by a detailed analysis of the CD signal utilizing an approach based on the Mueller matrix model. This report of a novel class of chiral hybrid semiconductors with precise control over their optical activity presents a promising approach for the design of circularly polarized light detectors and emitters.

Organic spintronics (OS), which focuses on utilizing the spin degree of freedom in organic materials, has been a fascinating topic because of its technological aspects and future applications. In-plane uniaxial magnetic anisotropy (UMA) is becoming increasingly important in the rapidly developing field of OS. In this study, Cobalt (Co) films were deposited with varying thicknesses on the Tris (8-hydroxyquinolinato) aluminium (Alq3) layer to investigate the evolution of magnetism and UMA. Magnetic measurements and simultaneous domain imaging have been done using the magneto-optic Kerr effect by varying the azimuthal angle between the easy axis of magnetization and the applied magnetic field. It was discovered that the bilayer exhibits a well-defined UMA in the film plane upon forming a continuous Co film with a thickness of around 10 nm. Structural and morphological properties of all the Co/Alq3 bilayers were studied using grazing-incidence small-angle X-ray scattering and wide-angle X-ray scattering measurements at synchrotron radiation source, P03 beamline PETRA-III, Germany. The combined analysis revealed that in contrast to the inorganic magnetic polycrystalline thin films, where the UMA originates mainly due to the stress, the origin of UMA in Co/Alq3 is attributed to the magnetocrystalline anisotropy caused by c-axis (Co (002)) preferential orientation. The surface free energy of Alq3 is less than that of Co; therefore, the growth of Co starts with island formation, which coalescences with increasing thickness. The observed structure orientation may be attributed to minimizing the magnetoelastic energies due to coalescence known as the zipping effect. The absence of UMA in films with lower thickness film (~5 nm) is understood in terms of random short-range stress caused by isotropic pinning due to the diffused interface. [ABSTRACT FROM AUTHOR]

Cellulose is a natural polymer with great properties such as high optical transparency and mechanical strength, flexibility, and biodegradability. Hence, cellulose‐based foils are suitable for the replacement of synthetic polymers as substrate materials in organic electronics. This article reports the fabrication of ultrathin, free‐standing cellulose foils by spraying aqueous 2,2,6,6‐tetramethylpiperidine‐1‐oxyl‐nanocellulose (TEMPO) fibrils ink layer‐by‐layer on a hot substrate using a movable spray nozzle. The resulting foils are only 2 ± 1 µm in thickness with an average basis weight of 1.9 g m−2, which ranges in the same scale as the world's thinnest paper. The suitability of these ultra‐thin nanocellulose foils as a sustainable substrate material for organic electronic applications is demonstrated by testing the foils resistance against organic solvents. Furthermore, silver nanowires (AgNWs) and the blend poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) are integrated into the foils, and the foils are molded into 3D paper structures in order to create conductive, paper‐based building blocks for organic electronics. [ABSTRACT FROM AUTHOR]

Electrode materials for application in lithium‐ion batteries are commonly probed by X‐ray diffraction (XRD) to investigate their crystalline structure. Grazing incidence wide‐angle X‐ray scattering (GIWAXS) is an extension to XRD since in‐plane structures are also accessible. Additionally, with grazing incidence small‐angle X‐ray scattering (GISAXS), morphological information on the nanoscale can be revealed. In this work, the nanostructure of battery electrodes, which consist of lithium iron phosphate (LiFePO4) as active material, carbon black (CB) as conducting agent, and the polymeric binders polyvinylidenefluoride (PVDF) and poly((trifluoromethane) sulfonimide lithium styrene) (PSTFSILi) is studied by performing GISAXS and GIWAXS. The chemical nature of the binder is tuned by blending PVDF and PSTFSILi. Specifically, a series of LiFePO4 electrodes with polymer blends of the common, non‐conducting PVDF and the single‐ion conducting PSTFSILi with different weight ratios as binders is investigated to understand the influence of the binder on the structure of the electrode in detail. Scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) complement these studies to correlate the morphology and structure with the electrochemical behavior. It is found that LiFePO4 crystallites do not exhibit any preferred orientation with respect to the substrate, irrespective of the binder composition, but their size depends on the binder composition. [ABSTRACT FROM AUTHOR]

The prospects of endowing stimuli‐responsive materials with various life‐like behaviors are promoting the development of intelligent robotic and electronic devices. However, it is challenging to incorporate stimuli‐responsive actuating and healing capabilities into one single material system. Herein, the design and assembly of humidity‐responsive thin films composed of poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and sodium carboxymethyl cellulose (NaCMC) forming a conducting polymer composite through a physically cross‐linked and hydrogen‐bonded supramolecular network are described. Owing to its enhanced dynamics of hydrogen bonding at an elevated humidity, the PEDOT:PSS/NaCMC thin film exhibits a rapid humidity‐responsive actuating performance in an environment with humidity gradient, as well as a repairing function of the structural, mechanical, electrical, and actuating properties after being damaged through a humidifying‐drying cycle. Based on a combined analytical approach, a structural model is proposed for the rearrangement of the thin film when being exposed to stepwise humidity levels at multi‐length scales. Due to the structural rearrangement powered by humidity variations, the film exhibits tunable actuating and healing performance, which makes it a promising candidate material for applications in intelligent soft robotics such as artificial muscles. [ABSTRACT FROM AUTHOR]

The nanomorphology of bulk heterojunctions (BHJs) plays a critical role in determining the performance of non-fullerene organic solar cells (OSCs). Thermal annealing is commonly used to reorganize the donor and acceptor phases within the BHJs. In this study, we investigate the vertical morphology of BHJ blend films incorporating the poly-[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3‴-di-(2-octyldodecyl)-2,2′;5′,2″;5″,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD) polymer as the donor and 3,9-bis-(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis-(4-hexylphenyl)-dithieno-[2,3-d:2′,3′-d′]-s-indaceno-[1,2-b:5,6-b′]-dithiophene (ITIC) as the acceptor. Neutron reflectivity patterns and scattering length density profiles reveal that the surface of the BHJ films became diffuse when the annealing temperature was above 150 °C. We further find that mitigated agglomeration of PffBT4T-2OD side chains exhibits minimal impact on morphology post-annealing. Instead, ITIC molecules trigger aggregations, accompanied by interface diffusion and increased film roughness. X-ray scattering confirms a 5-fold increase in aggregated ITIC nanodomains after annealing. Our findings highlight that unstable ITIC phases dominate the BHJ morphology of thin films, leading to the thermal instability of OSCs. This study enhances our understanding of the BHJ morphology and offers insights into improving the performance of energy conversion devices. [ABSTRACT FROM AUTHOR]

Highly sensitive and humidity‐resistive detection of the most common physical stimuli is of primary importance for practical application in real‐time monitoring. Here, a simple yet effective strategy is reported to achieve a highly humidity‐stable hybrid composite that enables simultaneous and accurate pressure and temperature sensing in a single sensor. The improved electronic performance is due to the enhanced planarity of poly (3,‐4ethylenedioxythiophene) (PEDOT) and charge transfer between PEDOT:polystyrene sulfonate (PEDOT:PSS) and multi‐walled carbon nanotubes (CNTs) by strong π–π interaction. The preferred electronic pathway induced by a robust morphology in the hybrid composite is responsible for the high humidity stability. This study also demonstrates that the sensor has tremendous potential for intelligent object identification with a high level of 97.78% accuracy. Together with the position‐detection capability of a triboelectric nanogenerator (TENG), advantages for potential industrial applications of the triple sensing system in terms of intelligent classification without seeing are foreseen. [ABSTRACT FROM AUTHOR]