Abstract 2D van der Waals (vdW) magnets open landmark horizons in the development of innovative spintronic device architectures. However, their fabrication with large scale poses challenges due to high synthesis temperatures (>500 °C) and difficulties in integrating them with standard complementary metal‐oxide semiconductor (CMOS) technology on amorphous substrates such as silicon oxide (SiO2) and silicon nitride (SiNx). Here, a seeded growth technique for crystallizing CrTe2films on amorphous SiNx/Si and SiO2/Si substrates with a low thermal budget is presented. This fabrication process optimizes large‐scale, granular atomic layers on amorphous substrates, yielding a substantial coercivity of 11.5 kilo‐oersted, attributed to weak intergranular exchange coupling. Field‐driven Néel‐type stripe domain dynamics explain the amplified coercivity. Moreover, the granular CrTe2devices on Si wafers display significantly enhanced magnetoresistance, more than doubling that of single‐crystalline counterparts. Current‐assisted magnetization switching, enabled by a substantial spin–orbit torque with a large spin Hall angle (85) and spin Hall conductivity (1.02 × 107ℏ/2e Ω⁻¹ m⁻¹), is also demonstrated. These observations underscore the proficiency in manipulating crystallinity within integrated 2D magnetic films on Si wafers, paving the way for large‐scale batch manufacturing of practical magnetoelectronic and spintronic devices, heralding a new era of technological innovation.
more »
« less
This content will become publicly available on September 1, 2026
Achieving Chemical Recognition, Recycling, and Circularity With Radical Nanostructures
Abstract Although still in its early stages, the production and investigation of 3D magnetic nanostructures signify a major advancement in both fundamental research and practical applications, with immense potential for next‐generation technologies. Here, for the fabrication of the 3D nanostructures, an innovative approach selecting aS= 1/2 4,4′‐dicyano‐2,2′‐biphenylene‐fused tetrazolinyl radical is adopted, chemically stable and thermodynamically robust, allowing thin film processing and growth. Interdigitated gold‐silicon dioxide hybrid surfaces are used as substrates since gold and silicon dioxide are two technologically relevant materials. The ability to: (1) grow radical nanostructures are demonstrated that retain their magnetic properties, (2) adjust their morphology and size, (3) selectively remove nanostructures from specific substrate regions using distilled water, and (4) return substrates to their pristine condition, making them reusable after washing. This research not only aims to produce innovative 3D nanostructures but also strives to improve efficiency and minimize consumption, aligning with the principles of circular economy. This approach is particularly beneficial for expensive materials, such as gold, or patterned hybrid substrates that require complex fabrication techniques.
more »
« less
- Award ID(s):
- 2247170
- PAR ID:
- 10644563
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 35
- Issue:
- 37
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract New deposition techniques for amorphous oxide semiconductors compatible with silicon back end of line manufacturing are needed for 3D monolithic integration of thin‐film electronics. Here, three atomic layer deposition (ALD) processes are compared for the fabrication of amorphous zinc tin oxide (ZTO) channels in bottom‐gate, top‐contact n‐channel transistors. As‐deposited ZTO films, made by ALD at 150–200 °C, exhibit semiconducting, enhancement‐mode behavior with electron mobility as high as 13 cm2V−1s−1, due to a low density of oxygen‐related defects. ZTO deposited at 200 °C using a hybrid thermal‐plasma ALD process with an optimal tin composition of 21%, post‐annealed at 400 °C, shows excellent performance with a record high mobility of 22.1 cm2V–1s–1and a subthreshold slope of 0.29 V dec–1. Increasing the deposition temperature and performing post‐deposition anneals at 300–500 °C lead to an increased density of the X‐ray amorphous ZTO film, improving its electrical properties. By optimizing the ZTO active layer thickness and using a high‐kgate insulator (ALD Al2O3), the transistor switching voltage is lowered, enabling electrical compatibility with silicon integrated circuits. This work opens the possibility of monolithic integration of ALD ZTO‐based thin‐film electronics with silicon integrated circuits or onto large‐area flexible substrates.more » « less
-
Abstract A goal in the field of nanoscale optics is the fabrication of nanostructures with strong directional light scattering at visible frequencies. Here, the synthesis of Mie‐resonant core–shell particles with overlapping electric and magnetic dipole resonances in the visible spectrum is demonstrated. The core consists of silicon surrounded by a lower index silicon oxynitride (SiOxNy) shell of an adjustable thickness. Optical spectroscopies coupled to Mie theory calculations give the first experimental evidence that the relative position and intensity of the magnetic and electric dipole resonances are tuned by changing the core–shell architecture. Specifically, coating a high‐index particle with a low‐index shell coalesces the dipoles, while maintaining a high scattering efficiency, thus generating broadband forward scattering. This synthetic strategy opens a route toward metamaterial fabrication with unprecedented control over visible light manipulation.more » « less
-
Abstract Microrobots hold immense potential in biomedical applications, including drug delivery, disease diagnostics, and minimally invasive surgeries. However, two key challenges hinder their clinical translation: achieving scalable and precision fabrication, and enabling non‐invasive imaging and tracking within deep biological tissues. Magnetic particle imaging (MPI), a cutting‐edge imaging modality, addresses these challenges by detecting the magnetization of nanoparticles and visualizing superparamagnetic nanoparticles (SPIONs) with sub‐millimeter resolution, free from interference by biological tissues. This capability makes MPI an ideal tool for tracking magnetic microrobots in deep tissue environments. In this study, “TriMag” microrobots are introduced: 3D‐printed microrobots with three integrated magnetic functionalities—magnetic actuation, magnetic particle imaging, and magnetic hyperthermia. The TriMag microrobots are fabricated using an innovative method that combines two‐photon lithography for 3D printing biocompatible hydrogel structures with in situ chemical reactions to embed the hydrogel scaffold with Fe3O4nanoparticles for good MPI contrast and CoFe2O4nanoparticles for efficient magnetothermal heating. This approach enables scalable, precise fabrication of helical magnetic hydrogel microrobots. The resulting TriMag microrobots, with the synergistic effects of Fe3O4and CoFe2O4nanoparticles, demonstrate efficient magnetic actuation for controlled movement, precise imaging via MPI for imaging and tracking in biological fluid and organs, including porcine eye and mouse stomach, and magnetothermal heating for tumor ablation in a mouse model. By combining these capabilities, the fabrication and imaging approach provides a robust platform for non‐invasive monitoring and manipulation of microrobots for transformative applications in medical treatment and biological research.more » « less
-
Article“Green” Fabrication of High-performance Transparent Conducting Electrodes by Blade Coating and Photonic Curing on PET for Perovskite Solar CellsJustin C. Bonner 1,†, Robert T. Piper 1,†, Bishal Bhandari 2, Cody R. Allen 2, Cynthia T. Bowers 3,4, Melinda A. Ostendorf 3,4, Matthew Davis 5, Marisol Valdez 6, Mark Lee 2 and Julia W. P. Hsu 1,∗1 Department of Materials Science and Engineering, University of Texas at Dallas, 800 W Campbell Road, RL-10, Richardson, TX 75080, USA2 Department of Physics, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA3 Materials Characterization Facility at the Air Force Research Laboratory, 2941 Hobson Way, WPAFB, OH 45433, USA4 UES, Inc., a BlueHalo Company, 4401 Dayton-Xenia Rd, Dayton, OH 45432, USA5 Energy Materials Corporation, 1999 Lake Ave B82 Ste B304, Rochester, NY 14650, USA6 Department of Chemistry, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA* Correspondence: jwhsu@utdallas.edu† These authors contributed equally to this work.Received: 30 September 2024; Revised: 25 October 2024; Accepted: 30 October 2024; Published: 5 November 2024Abstract: This study presents an innovative material processing approach to fabricate transparent conducting electrodes (TCEs) on polyethylene terephthalate (PET) substrates using blade coating and photonic curing. The hybrid TCEs consist of a multiscale Ag network, combining silver metal bus lines and nanowires, overcoated by an indium zinc oxide layer, and then photonically cured. Blade coating ensures film uniformity and thickness control over large areas. Photonic curing, a non-thermal processing method with significantly lower carbon emissions, enhances the conductivity and transparency of the coated layers. Our hybrid TCEs achieve an average transmittance of (81 ± 0.4)% referenced to air ((90 ± 0.4)% referenced to the PET substrate) in the visible range, an average sheet resistance of (11 ± 0.5) Ω sq−1, and an average surface roughness of (4.3 ± 0.4) nm. We benchmark these values against commercial PET/TCE substrates. Mechanical durability tests demonstrate <3% change in resistance after 2000 bending cycles at a 1 in radius. The scalable potential of the hybrid TCE fabrication method is demonstrated by high uniformity and excellent properties in 7 in × 8 in large-area samples and by performing the photonic curing process at 11 m min−1. Furthermore, halide perovskite solar cells fabricated on these hybrid TCEs achieve average and champion power conversion efficiencies of (10.5 ± 1.0) % and 12.2%, respectively, and significantly outperform devices made on commercial PET/TCEs. This work showcases our approach as a viable pathway for high-speed “green” manufacturing of high-performance TCEs on PET substrates for flexible optoelectronic devices.more » « less
An official website of the United States government
