bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Highly Stable Metal-Oxide Thin-Film-Transistors and Circuits for Large-Area Flexible and Stretchable Electronics
Authors: Park Sung Kyu 
Published: December 2024

Thin-film transistors (TFTs) have been considered as an essential component in modern sensory and displays due to their unique electrical properties for pixel and circuit applications, as well as their compatibility with low-cost manufacturing and large-area substrates. As the thin-film electronics have rapidly advanced toward much complex functionality along with higher resolutions and refresh rates, especially with the emergence of area-scalable wide form factors such as large-area foldable and stretchable displays, the features and materials of the TFT devices must evolve to meet these demands. Metal-oxide (MO) TFTs have emerged as a promising platform to facilitate the evolution of electronic products in terms of uniformity, conformability, and reduced manufacturing costs, while enabling large-area electronics on flexible and stretchable substrates due to their cost-effective fabrication and high uniformity.However, despite these advances expanding the potential applications of MO TFTs, implementing highly robust flexible/stretchable MO TFTs with good electrical performance remains somewhat challenging. In this presentation, recent technologies 1-
4 for the structural and material approaches to achieve robust and stable high-form factor MO TFTs are introduced. Additionally, the envision and outlook for more versatile strategy to advance the development of commercial-level high-form factor electronics will be fully discussed.
References

Kim, Y.-H and S. K. Park. et al. Flexible metal-oxide devices made by room-temperature photochemical activation of sol-gel films.
Nature

..
2012
,
489,

-W Jo, J. K. Kim, K.-T. Kim, J.-G. Kang, M.-G. Kim, K.-H. Kim, H. Ko, Y.-H. Kim, and S. K. Park, “Highly stable and imperceptible electronics utilizing photo-activated heterogeneous sol-gel metal-oxide dielectrics and semiconductors”,
Advanced Materials

,
2015, 27, 1182

T. Kim, S. Moon, M. Kim, J.-W. Jo, C. Y. Park, S. H. Kang, Y.-H. Kim, and S. K. Park, “Highly scalable and robust mesa-island structure metal-oxide thin-film-transistors and integrated circuits enabled by stress-diffusive manipulation”,
Advanced Materials

,
2020, 32, 2003276.

H. Kang, J. -W. Jo, J. M. Lee, Y.-H. Kim, J.-W. Kim, S. K. Park, “Full integration of highly stretchable inorganic transistors and circuits within molecular-tailored elastic substrates on a large scale”
Nature Communications
, 2024, 15, 2814
(Invited) Group III-Nitride Nanostructures and Devices: From Classical Optoelectronics to Artificial Photosynthesis
Authors: Sadaf Sharif , Anand Nirmal , Ghosh Dipon , Rahman Md Afjalur , Jenson Christy G 
Published: December 2024

Third generation, group III-nitrides (InN, GaN, AlN and their alloys) semiconductor nanostructures have emerged as an important class of materials for a host of critical applications ranging from classical optoelectronics to quantum to artificial photosynthesis (i.e., photo(electro) chemical water splitting and CO2 reduction). Group III-nitrides exhibit unique properties including broad, tunable, direct energy bandgap, large exciton binding energy, giant spontaneous and piezoelectric polarization field, perfect conduction/valence band edge positioning to drive the redox reactions for fuel productions, interesting surface/interface properties, making them the only materials of choice for the afore-mentioned applications. In this talk, I will first present some recent advances of their epitaxy growth/synthesis, electronic, optical, and quantum properties, including the development of high efficiency visible and deep UV LEDs/laser diodes, and the realization of monolithic micro-LEDs.
A highly efficient and robust artificial photosynthesis integrated device and system (APIDS) is the key for achieving carbon-neutral alternative to fossil fuels. III-nitrides can be used as an ideal building block of APIDS because of their recently discovered photocatalytic properties demonstrating great potential in artificial photosynthesis compared to decade long studied photocatalysts. Herein, the most recent advance in the utilization of III-nitrides-based artificial leaves for building a carbon-neutral substance and energy recycling system will be presented, focusing on solar water splitting toward H2 and solar CO2 reduction toward fuels and chemicals. I will also present on III-nitrides nanostructures-based non-classical on-demand quantum light sources (single photon and entangled photons sources) generation and their usage in quantum communication and optical quantum computing protocols. Overall, the talk focuses on the unique potential of group III-nitrides materials for emerging applications.
An Investigation on the Low Voltage Ferroelectric Hf0.5Zr0.5O2 Capacitor Deposited on Phase-Controlled W Electrode
Authors: Yang Kun , Jeong Hyun Woo , Park Ju Yong , Lee Jaewook , Choi Hyojun , Lee Younghwan , Park Min Hyuk 
Published: December 2024

Since the unexpected ferroelectric properties were first reported in HfO2 thin films in 2011, this material has emerged as a promising candidate for next-generation ferroelectric memory devices.[1] They are noted for their sub-10 nm thickness and compatibility with the complementary metal-oxide-semiconductor (CMOS) process. The polarization switching of ferroelectric materials is initiated when an external electric field exceeding their coercive field (Ec) is applied. Yet, the Ec value of ferroelectric HfO2 (1.0-2.0 MV/cm) is higher than that of perovskite ferroelectric materials (0.01-0.1 MV/cm), another ferroelectric material.[2] This indicates that there is a significant challenge in reducing the operation voltage for the ferroelectric HfO2 films to a certain value. Consequently, the HfO2-based capacitor that is switchable at low voltages could be applied to high-efficiency electrical devices. From this perspective, this study reports on the ferroelectric properties, especially focusing on low operation voltage (<1.6 V), of Hf0.5Zr0.5O2 (HZO) thin films deposited on phase-controlled tungsten (W) electrodes. Tungsten can be stabilized to W-α or W-β phases through controlled fabrication conditions of the sputtering system.[3] It could be confirmed that a relatively low working pressure (<4 mTorr) may stabilize the W-α phase, and a high working pressure (>8 mTorr) may stabilize the W-β phase, as analyzed by XRD (X-ray diffraction) analysis. The 8 nm HZO thin films were deposited via the ALD (atomic layer deposition) process on the 50 nm W-α and W-β electrodes. Under a low applied voltage (~1.6 V), the HZO thin films on W-α exhibit a high value of 2Pr (double remanent polarization) = 33.58 μC/cm2, while the HZO thin films on W-β show a high endurance cycle of more than 109 electric field cycles. This result can be attributed to the low Ec of the HZO thin film on W-α and W-β electrodes, 0.78 and 0.69 MV/cm, under an applied voltage of 1.6V. The notably low Ec values facilitate operations at low voltages while enhancing endurance by minimizing the electrical stress on the ferroelectric thin film. This study underscores the significance of electrode engineering in augmenting the ferroelectricity and the endurance of the HZO thin film, presenting a viable strategy for designing low-voltage and high-reliability metal-ferroelectric-metal (MFM) devices.
[1] Böscke, T. S., et al., Appl. Phys. Lett. 99.10: 102903. (2011)
[2] Lee, J., et al., Nano Converg. 10.1: 55. (2023)
[3] O’keefe, M. J., et al., J. Electron. Mater., 24, 961-967. (1995)

Figure 1
All Solution-Processed High-Performance MoS2 Thin Film Transistors with the High-k Perovskite Oxide Dielectric
Authors: Joung Su-Yeon , Lee Chul-Ho 
Published: December 2024

Solution-processable van der Waals (vdW) materials with atomic layered crystal structures, are increasingly recognized as promising components for emerging electronic device applications. These materials offer exceptional quality and stability, coupled with the advantage of large-scale and low-temperature processability. Among these, van der Waals-assembled thin films made from transition metal dichalcogenides in solution have recently emerged as highly potential candidates for fabricating high-performance thin-film transistors (TFTs). Despite recent progress, fully solution-processed vdW electronics remain elusive, primarily due to the absence of suitable dielectric materials and scalable fabrication methodologies.
In this report, we introduce the all solution-processed MoS2 TFTs, incorporating perovskite oxides as high-k gate dielectrics. The fabrication process involves preparing colloidal inks for each constituent layer through chemical or electrochemical exfoliation methods, followed by sequential assembly processes forming the semiconductor/dielectric heterostructure. All fabrication steps are performed at temperatures below 250 ℃. The resulting MoS2 TFTs, utilizing Dion-Jacobson-phase perovskite as the dielectric layer, demonstrate superior device characteristics. Notably, they exhibit an ON/OFF ratio exceeding 106, including high mobility (>10 cm2 V-1s-1). Additionally, the integration of high-k dielectric materials enables the transistors to operate at low leakage current (~10-11 A) and very low voltages, around approximately 5 V, significantly reducing power consumption. These TFTs are also compatible with flexible substrates, which further demonstrates their robustness and adaptability in a variety of electronic applications. The successful demonstration of low-temperature fabrication techniques for high-performance MoS2 TFTs not only marks a significant advancement in the field of solution-processable electronic devices but also paves the way for cost-effective, scalable electronics that are capable of hetero-integration.
Engineering High-Color Purity Photonic Crystal Strain Sensors via Melt-Shear Process
Authors: Lee Sang Hoon , Kim Young-Seok 
Published: December 2024

Non-close-packed colloidal photonic crystals (CPhCs) are a class of optical materials characterized by their ability to reflect specific wavelengths of light, determined by the arrangement of constituent particles. The manipulation of particle spacing enables precise control over the reflected color, offering versatile coloration capabilities via mechanical or electrical means. This property renders CPhCs highly promising for diverse applications across various fields.
In this investigation, our focus lies on developing a method for fabricating uniform photonic crystal films with exceptional color purity through a uniform melt-shear process. Leveraging polystyrene@poly(methylmethacrylate)@poly(ethyl acrylate) (PS@PMMA@PEA) core-intermediate-shell (CIS) particles with polydopamine (PDA), we crafted stretchable films with tailored optical properties. By subjecting the amorphous CIS particles to high shear force, we induced alignment and crystallization during the melt shear process, yielding films with enhanced crystallinity. The superior color purity exhibited by these films stems from the absorption of scattered light by the PDA coating, which effectively suppresses unwanted reflections. To optimize the active reflection layers, we systematically varied parameters including process temperature, shear rate, pressure, thickness, and stacking method of films. This comprehensive optimization strategy culminated in photonic crystal films capable of seamless color transitions from red to blue. Such remarkable color-changing properties hold significant promise for applications in biomimetic strain and stress sensing, where precise and responsive color variations are desirable indicators.
(Invited) Edge-Computing Multimodal Flexible Sensor System
Authors: Takei Kuniharu 
Published: December 2024

Daily continuous condition monitoring is now of great interests using multi-functional flexible sensors for a variety of applications including healthcare, medicine, and internet of things (IoT). Due to significant developments of wearable electronics including flexible/stretchable devices, non-invasive, home-use, personal healthcare monitoring is getting realistic in near future. Using this device platform, it is possible to realize early-stage diagnosis and remote medicine. For this purpose, vital signals from skin are the most convenient way to measure continuously data collections during daily life. Flexible sensor sheets allow it to detect multiple information including physical and chemical parameters such as electrocardiogram, respiration, temperature, perspiration, chemical contents in a body from skin precisely due to conformable covering over skin surface. To realize this platform, multiple developments including flexible sensors, wireless system, and edge system to analyse huge size of datasets are required. In this talk, I introduce a wireless multiple sensor sheet with real-time data analyses on a smartphone as an edge system. The system has a function to display real-time analysed results on a smartphone to notify the users about their conditions.
Although a lot of researches and developments are still required for practical application, these studies may help to open a door for the next step of flexible electronics.
(Invited) Hot Electron Photodetectors, Sensors and Solar-Cells
Authors: Nunzi jean-Michel , Poushimin Rana 
Published: December 2024

Plasmonic nanostructures can generate energetic “hot” electrons from light in a broad band fashion depending on their shape, size, and arrangement. These nanostructures have a promising use in photodetectors, allowing high speed, broad band, multicolor and polarized photodetection. Because they function without a band-to-band transition, photon detection at any energy is possible through engineering of the plasmonic nanostructure. Compact hot-electron-based photodetectors that combine polarization sensitivity and light detection in the near-infrared region were fabricated using an indium tin oxide (ITO)−gold hybrid layer.[1] Sensitivity of the device was significantly increased by use of self-assembled monolayers in a capacitor configuration. The resulting devices are capable of detecting light below the ITO band gap at ambient temperature without any bias voltage. The devices can also function as photovoltaic solar cells using an electrolyte which provides charge transport to the electrodes (Fig 1).[2] Interestingly the surface sensitivity of the hot electron emission effect can be used for femtomole sensitivity.

Figure 1: current voltage characteristic under 1 sun AM 1.5 solar simulation of an array of gold nano-antenna cathode hot-electron emission dye-sensitized-like solar cell.

References:

[1] ‘Simple Unbiased Hot-electron Polarization-sensitive Near-Infrared Photo-detector’, S.M.A. Mirzaee, O. Lebel, J.M. Nunzi, ACS Appl.Mater.Inter. 10, 11862-11871 (2018)
[2] ‘Requirements for a rectifying antenna solar cell technology”, J.M. Nunzi, Proc SPIE 7712, 771204 (2010).

Figure 1
(Invited) the Future of MOFs - Asking the Question - "What Needs to be True?"
Authors: Miller Stuart Raymond 
Published: December 2024

The urgent need to decarbonize society to combat climate change has spurred significant interest in developing new materials capable of directly or indirectly reducing our global carbon footprint through technologies including carbon capture, electrolysis and novel energy storage systems.
Over the last 25 years, Metal-Organic Frameworks (MOFs) have gained significant attention owing to their potential in fields of gas adsorption, separation and energy storage. However an extremely limited number of MOFs have demonstrated commercial success. This presentation will ask the question why MOFs have not been more industrially successful and why the 2015 Paris Agreement offers opportunities uniquely suitable for MOFs. Challenges such as scalability, cost, and integration with existing infrastructures will be discussed, alongside the potential environmental impacts of new material production.
This presentation will introduce Underwriters Laboratories Research Institutes newest institute, the Materials Discovery Research Institute (MDRI) which leverages a computational and theoretical approach to target materials designed to specific applications coupled with advanced automated synthesis methodologies and an entirely digital Laboratory Information Management System.
Ordered Transfer from 3D-Oriented MOF Superstructures to Polymeric Films and Patterns
Authors: Falcaro Paolo , Brandner Lea 
Published: December 2024

Three-dimensional oriented metal-organic frameworks, or 3D-oriented MOFs, feature precisely arranged pores that extend over large areas. This order is essential for enhancing directed diffusion and arranging functional guest species within the oriented pore channels. [1] For example, pore orientation in porous MOF matrices is desired for photonics and ion conductivity uses.[2] Yet, 3D-oriented MOF films and patterns can rapidly decompose in the presence of moisture and acidic environments. [3] This propensity to degradation limits their applicability.
Here, by starting with MOF films that are N3-functionalized and heteroepitaxially aligned, we promote the formation of an oriented polymeric film. With X-ray lithography, we target the azide groups for selective degradation thus enabling the crosslink in defined regions: this fabrication process enables the preparation of porous polymeric patterns. The water-stable porous polymer patterns showed unique fluorescent behaviour when exposed to polarized light, which holds promise for advancing optical and photonic devices. [4]

References

[1] M. Linares‐Moreau, L. A Brandner, M. de J Velásquez‐Hernández, J. Fonseca, Y. Benseghir, J.M. Chin, D. Maspoch, C. Doonan, P. Falcaro Adv.Mater.
2024, 36, 2309645
[2] M.d.J. Velásquez-Hernández, M. Linares-Moreau, L.A. Brandner, B. Marmiroli, M. Barella, G.P. Acuna, S.D, Zilio, M.F.K. Verstreken, D.E. Kravchenko, O.M. Linder-Patton, J.D. Evans, H. Wiltsche, F. Carraro, H. Wolinski, R. Ameloot, C. Doonan and P. Falcaro. Adv.Mater.
2023, 35, 2211478.
[3] L.A Brandner, M. Linares-Moreau, G. Zhou, H. Amenitsch, S. Dal Zilio, Z. Huang, C. Doonan, P. Falcaro Chem.Sci.,
2023, 14, 12056.
[4] L.A. Brandner, B. Marmiroli, M. Linares-Moreau, M. Barella, B. Abbasgholi-NA, M.de J. Velásquez-Hernández, K. L. Flint, S.Dal Zilio, G. P. Acuna, H. Wolinski, C. J. Doonan, P. Falcaro, Submitted.
(Invited) open the Gate: Molecular Dynamics Simulation of Adsorption-Induced Phase Transformations of MOF Nanocrystallites
Authors: Schmid Rochus 
Published: December 2024

One of the most intriguing features of Metal-organic frameworks (MOFs) is their ability to respond to external stimuli, like the adsorption of guest molecules, with large changes in the accessible pore volume. Theoretical simulations are a key tool to understand such “gate opening” processes on a molecular level. This is typically done within the approximation of periodic boundary conditions (PBC) and using Grand Canonical methods. Such simulations exclude, however, the interface between the MOF and the gas reservoir and ignore any transport effects, which limits them to the thermodynamic equilibrium. Especially for sensing applications, the kinetics of such processes can become important. Recently, our group started to develop and apply methods to simulate MOF nanocrystallites (NCs) beyond PBC, to circumvent such limitations [1,2,3].
In the presentation, recent results on the pore opening of DUT-8(Zn) nanocrystallites in carbon dioxide will be shown. Unbiased molecular dynamics simulations reveal a rather fast phase transformation within a few nanoseconds. The first-order phase transition is initiated by a characteristic pore opening at a corner of the crystallite. The anisotropy of the pillared-layer MOF with its channels along the crystallographic c-axis leads to a specific transport pattern for the guest molecules when the pore opening of the MOF proceeds. The simulations allow an unprecedented view of the actual process, including both the mechanics of the phase transformation of the MOF and the diffusive transport of the guest molecules from the reservoir into the MOF.
[1] J. Keupp, R. Schmid, Adv. Theory Simul. 2019, 2, 1900117.
[2] L. Schaper, J. Keupp, R. Schmid, Front. Chem. 2021, 9, 757680.
[3] L. Schaper, R. Schmid, Commun. Chem. 2023, 6, 233.
Effect of Concentration and Addition Timing of Bromide Ion on Synthesis of Thin Silver Nanowires (AgNW)
Authors: Shimizu Keiya , Aoki Atsushi 
Published: December 2024

Indium tin oxide (ITO), currently widely used as a transparent conductive material to OLED, solar cells and EC devices, has advantages such as low sheet resistance and high transmittance, but it has defects such as inflexibility, fragility and vacuum process production. Alternative transparent conductive materials are required to replace ITO. Silver nanowires (AgNW) have one of attractive attention because AgNW dispersed films show low sheet resistance and high transparency, and even more excellent flexibility, and solution process production. However, the current AgNW films have higher resistance than that of ITO because diameter of AgNW is sub mm order and poor formation of two-dimensional network of AgNW. Therefore, we aimed to reduce the resistance of AgNW film by thinning diameter of AgNW, which is expected to improve conductivity by increasing number of AgNW while maintaining transparency.
Synthesis thinning diameter of AgNW was performed by a polyol reduction method using polyvinylpyrrolidone (PVP) and Br- ion as capping agents, and Ag+ ion was reduced to Ag metal by thermal decomposition of ethylene glycol. As PVP and Br- ion are selectively adsorbed on Ag(100) plane, Ag(111) plane grew, resulting in AgNW production. The reactant solution including NaCl, NaBr, PVP, and AgNO3 in ethylene glycol was heated to 130 ˚C to synthesize AgNW. Br- ion was first added before heating, and the synthesis was carried out at NaBr concentrations ranging from 0 µM to 59.8 µM. As a result, AgNW production was confirmed at the low NaBr concentrations below 53.1 µM, but thin AgNW was not observed. At the high NaBr concentration above 53.1 µM, no AgNW synthesis was observed because Br- ion inhibited the growth of AgNW.
Next, we examined the timing of addition of Br- ion at the NaBr concentration of 53.1 µM. When excess Br- ion was added before heating, we supposed that it would inhibit the formation of AgCl nuclei and prevent AgNW growth. When Br- ion was added within 1 hour after the start of heating, the growth of AgNW was inhibited by Br- ion and the synthesis of AgNW could not be confirmed as same as the case of NaBr addition before heating. Addition of Br- ion over 1 hour after the start of heating did not also result in the formation of thin AgNW because the growth of thick AgNW had already been completed. By addition of Br- ion at 1 hour after the start of heating, the formation of thin AgNW was observed.
The crude dispersed AgNW solution was diluted in ethanol and then stood for several hours to precipitate thick AgNW. The supernatant solution was pipetted and thin AgNW was precipitated by adding acetone to remove ethylene glycol. The purified thin AgNW were deposited on glass slides by the spray-coating method. Annealing of the deposited substrate at 130 ˚C was used to confirm the decrease in resistance. As a result of resistance measurement, a sheet resistance of 34.6 Ω/sq was achieved at 90% transmittance, and the transparent conductive material was successfully fabricated.