Article
Chemistry, Multidisciplinary
Yidong Hou, Meng Qiu, Zhaolong Cao, Jie Zhou, Hock Chun Ong, Wei Jin, Jinglei Du, Dangyuan Lei
Summary: This study demonstrates that propagating surface plasmon polaritons can significantly enhance the Q-factors of localized surface plasmon resonance related circular dichroism in plasmonic lattices with chiral unit cells. The interaction between dispersive achiral SPPs and nondispersive chiral LSPR results in the formation of hybrid chiral SPPs, allowing efficient tuning of transmission CD dispersion and signal intensity.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Jamal Ahmad Khan, Yogita Maithani, J. P. Singh
Summary: In this study, Ag2Se nanorod arrays were fabricated using the GLAD technique and two-zone furnace, and Ag2Se planar films of different thickness were also prepared. The tilted Ag(2)Se nanorod arrays exhibited excellent thermoelectric performance with zT of 1.14 and a power factor of 3229.21 μW/m-K-2 at 300 K. The superior thermoelectric properties of the nanorod arrays could be attributed to the unique nanocolumnar architecture that facilitated efficient electron transport and phonon scattering at the interfaces. Furthermore, the nanoindentation measurements showed that the nanorod arrays had lower hardness values and elastic modulus compared to the Ag(2)Se films, indicating improved mechanical properties. The synergistic dependence between the tilt structure and thermoelectric properties, along with the simultaneous improvement in mechanical properties, provides a new avenue for the practical applications of Ag2Se in next-generation flexible thermoelectric devices.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Ting Xiao, Jie Zhao, Peng Sun, Peng Li, Yaokang Zhang, Ni Zhao, Zhiwei Ren, Gang Li, Zhifeng Huang, Zijian Zheng
Summary: The study introduces a new type of broadband-transmitting built-in TiO2 metalens that can enhance the sensitivity, speed, and efficiency of photodetectors.
Article
Multidisciplinary Sciences
Xin-Xian Wu, Cheng-Yu Lu, Tsung-Yu Huang
Summary: In this study, an oblique-flat-sheet metamaterial perfect absorber (MPA) was designed to enhance the sensitivity of a biosensor. By simulating and conducting experiments, it was confirmed that the MPA had higher sensitivity.
SCIENTIFIC REPORTS
(2022)
Article
Materials Science, Multidisciplinary
Mengsheng Yang, Kewei Gao, Pifeng Xing, Taimin Yi, Zhibing He, Bo Ke
Summary: Gold nanoarray films prepared by glancing angle deposition exhibit different thermal stabilities and degradation mechanisms based on their structural features at different temperatures.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Jie Zhao, Peng Sun, Zhongwei Wu, Jun Li, Xiaohan Wang, Ting Xiao, Lin Yang, Zijian Zheng, Zhifeng Huang
Summary: The use of titanium-based metal nanopillar arrays (NaPAs) along with a 5 nm thick TiO2 passivation layer can significantly improve the efficiency of perovskite solar cells and enhance long-term stability.
Article
Engineering, Electrical & Electronic
Vinit Kumar Yadav, Amitabha Nath, Abhijit Das, Julaiba Tahsina Mazumder, Mitra Barun Sarkar
Summary: Enhanced photosensing performance was reported for Indium nanoparticles capped TiO2 nanowire array using GLAD technique, showing high ideality factor and improved photoresponsivity. The ON/OFF switching irradiation for the In NPs based photosensor increased with quick rise and fall times.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Zachary R. Lawson, Arin S. Preston, Matiyas T. Korsa, Nathaniel L. Dominique, Walker J. Tuff, Eli Sutter, Jon P. Camden, Jost Adam, Robert A. Hughes, Svetlana Neretina
Summary: This article demonstrates an assembly route for the fabrication of aligned plasmonic gold trimers with air-filled vertical nanogaps, exceeding the spatial controls of standard lithographic techniques. By utilizing specific process steps and control measures, precise positioning of nanogaps and metal assembly, as well as characterization of the optical response of the structures, were achieved.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Engineering, Electrical & Electronic
Atul Kumar Singh, Priyanka Chetri, Michael Cholines Pedapudi, Jay Chandra Dhar
Summary: Two different junction devices were fabricated using glancing angle deposition technique. The characteristics of the devices were confirmed by FE-SEM and TEM analysis. The I-V characteristics and rectification ratio indicated the formation of good Schottky and p-n junctions. The specific detectivity and noise equivalent power were measured, and the devices showed fast response.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Zijian Zhou, Kai Ou, Jiahong Dai, Wenting Zhang, Yongliang Tang, Yuxiang Ni, Yudong Xia, Hongyan Wang
Summary: In this study, multifold TiO2 nanorods with highly efficient photocatalytic performance for H-2 production were prepared using electron beam evaporation. The effects of annealing temperature and morphological structure on the photocatalytic performance were investigated. The optimal annealing conditions were found to be 550°C for 300 min in air. The multifold nanorods showed improved photocatalytic performances compared to the no-fold nanorods, with Z2 achieving a maximum photocurrent density of 1.35 mA/cm(2), which was six times higher than Z0 (0.2 mA/cm(2)). The smaller overall charge transfer resistance and larger BET surface area of Z2 were identified as the reasons for the maximum photocurrent density. The increase in specific surface area and number of active sites in the multifold structure contributed to the improved photocatalytic performance.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Laishram Thoibileima Chanu, Naorem Khelchand Singh
Summary: This study successfully presents the growth of NiO nanowire on Si substrate using the GLAD technique, and various analysis methods confirm its excellent performance characteristics, such as well-aligned growth, stable crystal structure, and larger bandgap. The fabricated device exhibits high responsivity, detectivity, and photosensitivity, along with rectifying behavior and low noise equivalent power. Furthermore, the device shows fast response time and a large linear dynamic range, making it a promising candidate for photodetector applications.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Coatings & Films
MaCayla J. Caso, Michael G. Benton, Kevin M. McPeak
Summary: Colloidal lithography (CL) is a promising method for large-scale fabrication of nanohole and nanodot arrays with various applications. Tilt-rotate evaporation colloidal lithography (TRE-CL) overcomes the trade-off between hole diameter and polydispersity, allowing for higher pitch-to-hole-diameter ratios and smaller hole sizes while maintaining low coefficient of variation and good hole circularity.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Review
Chemistry, Multidisciplinary
Jang-Hwan Han, Doeun Kim, Juhwan Kim, Gyurin Kim, Peer Fischer, Hyeon-Ho Jeong
Summary: Physical shadow growth is a vacuum deposition technique that allows the fabrication of various 3D-shaped nanoparticles and structures using a wide range of materials. Recent advancements in controlling the shadow effect at the nanoscale has expanded the capabilities of nanomaterials to include complex 3D-shaped hybrid nanoparticles and structures. By engineering the shape and material composition, plasmonically active nanomaterials with unique physical and chemical properties can be created. This review discusses the recent progress in the development of shadow growth techniques for hybrid plasmonic nanomaterials, describing how fabrication enables engineered material responses and highlighting novel functions. Potential applications in photonic devices, biomedicine, and chiral spectroscopy are also discussed.
ADVANCED MATERIALS
(2023)
Article
Engineering, Mechanical
Meenu Pandey, Divya Verma, Viswanath Balakrishnan, Nitya Nand Gosvami, J. P. Singh
Summary: The research revealed that patterned silver surfaces exhibit anisotropic friction behavior, with significant differences in coefficient of friction values when sliding in different directions on one-arm and two-arm nanocolumnar structures under varying normal load.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Yi-Jun Jen, Wei-Chieh Ma, Ting-Yen Lin
Summary: By obliquely bidepositing TiN thin films with different subdeposit thicknesses, this study observed a morphological transition from a nano-zigzag array to vertically grown columnar structures. The obtained principal refractive indexes explained the anisotropic transmission and reflection, showing the potential for tunable anisotropic properties in TiN nanostructured films for future multilayer designs. The film with a subdeposit thickness of 3 nm exhibited low refractive index and extinction coefficient for visible wavelengths, indicating promising characteristics for applications in optical devices.
Article
Chemistry, Multidisciplinary
Dongguen Shin, Fengshuo Zu, Edgar R. Nandayapa, Lennart Frohloff, Emily Albert, Emil J. W. List-Kratochvil, Norbert Koch
Summary: In this study, it is revealed that a straddling type-I energy level alignment is present at the 2D PEA(2)PbI(4)/3D MAPbI(3) interfaces, explaining the enhanced photoluminescence of the 3D perovskite induced by energy transfer from the 2D perovskite. These results provide a fundamental understanding of the electronic properties at the investigated 2D/3D MHP interfaces and suggest reconsideration of the electronic properties of other 2D/3D MHP heterostructures.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Dominique Lungwitz, Ahmed E. Mansour, Yadong Zhang, Andreas Opitz, Stephen Barlow, Seth R. Marder, Norbert Koch
Summary: The ability to form multi-heterolayer (opto)electronic devices by solution processing of semiconducting polymer layers is of great interest, but it poses challenges for multilayer deposition. Two mechanisms, including doping-induced pre-aggregation and the use of a photo-reactive agent, are found to enhance the solvent resistance of solution-processed doped polymer layers while retaining the dopants. For molecularly doped poly(3-hexylthiophene-2,5-diyl) and poly[2,5-bis(3-tetradecyl-thiophene-2-yl)thieno(3,2-b)thiophene] layers, pre-aggregation plays a major role in enhancing solvent resistance, but limits the use of a cross-linking agent. However, by suppressing pre-aggregation, high resistance to solvent and retained electrical conductivity can be achieved using a tris(azide) cross-linking agent.
CHEMISTRY OF MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Lennart Frohloff, Fengshuo Zu, Dongguen Shin, Norbert Koch
Summary: One promising approach for fabricating high-performance solar cells is to combine metal halide perovskites with organic semiconductors. Proper energy level alignment at device interfaces is crucial for achieving high device performance. In this study, we investigate the interface between a triple cation perovskite and an electron acceptor molecule and find that charge transfer induces a band bending effect, altering the charge extraction barriers. Additionally, we observe reversible shifts in the energy levels of the organic layer under white light illumination, indicating an electrostatic origin of this phenomenon.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Physics, Applied
Ross Warren, Paul W. M. Blom, Norbert Koch
Summary: This study measures the dielectric constant in thin films of regioregular poly(3-hexylthiophen-2,5-diyl) (P3HT) using impedance spectroscopy. The results show that molecular doping has a considerable impact on the dielectric constant.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Meysam Raoufi, Sreelakshmi Chandrabose, Rongbin Wang, Bowen Sun, Nicolas Zorn Morales, Safa Shoaee, Sylke Blumstengel, Norbert Koch, Emil List-Kratochvil, Dieter Neher
Summary: Monolayer transition-metal dichalcogenides (TMDCs) combined with organic semiconductors form heterostructures with tunable optoelectronic properties. The efficiency and lifetime of photoinduced charge transfer can be controlled by tuning the energy level offset. Direct electron-hole recombination across the hybrid interface is not the main decay pathway for photogenerated carriers, instead, holes are suggested to transfer back to the TMDC layer. Adding a 1 nm LiF interlayer can slow down interfacial carrier recombination without suppressing free carrier formation.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Jie Ma, Patrick Amsalem, Thorsten Schultz, Xiaomin Xu, Norbert Koch
Summary: Combining transition metal dichalcogenides (TMDCs) with molecular semiconductors allows for the formation of van der Waals heterostructures with unique optoelectronic properties. A strong p-type molecular dopant, F(6)TCNNQ, is used to create a van der Waals interface with a WS2 monolayer, resulting in no strong interaction or charge transfer. However, the presence of defects in the WS2 monolayer induces strong n-type doping and leads to pronounced charge transfer upon F(6)TCNNQ adsorption.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Thorsten Schultz, Peer Baermann, Elena Longhi, Rahul Meena, Yves Geerts, Yury Gogotsi, Stephen Barlow, Seth R. Marder, Tristan Petit, Norbert Koch
Summary: Two-dimensional MXenes, especially Ti(3)C(2)Tx, have promising properties for various applications. The work function of MXenes is crucial for energy level alignment, and methods to control the work function should be developed.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Ahmed E. Mansour, Ross Warren, Dominique Lungwitz, Michael Forster, Ullrich Scherf, Andreas Opitz, Moritz Malischewski, Norbert Koch
Summary: This study presents a simple method to enhance the oxidation strength of molecular dopants for organic semiconductors, while reducing diffusion in polymer hosts. Experimental results demonstrate higher efficiency of the new dopant complex compared to traditional molecular dopants.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Filippo Giovanni Fabozzi, Nikolai Severin, Jurgen P. Rabe, Stefan Hecht
Summary: In this study, the on-surface polymerization of a vinylene-linked single-layer two-dimensional covalent organic framework using reversible Knoevenagel polycondensation under solvothermal conditions was described. The self-assembly of monomer building blocks at the solid-liquid interface led to the formation of extended covalent networks at room temperature without the need for additional catalysts or reagents. This approach provides a new pathway for the synthesis of extended conjugated 2D polymers under mild conditions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Materials Science, Coatings & Films
Jeong Won Kim, Ansoon Kim, Hui Ung Hwang, Jun Hyung Kim, Seungwook Choi, Norbert Koch, Dongguen Shin, Zhijuan Zhao, Fen Liu, Minki Choi, Kyu Myung Lee, Yongsup Park
Summary: In this study, the results of an interlaboratory research on work function (WF) measurements by ultraviolet photoelectron spectroscopy (UPS) were presented. Two samples, gold (Au) film and highly oriented pyrolytic graphite (HOPG), were distributed to six different laboratories. The consistent results obtained from different laboratories demonstrate the basis for establishing a new international standard for UPS in the surface chemical analysis community.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Materials Science, Multidisciplinary
Johannes Mueller, Max Heyl, Thorsten Schultz, Kristiane Elsner, Marcel Schloz, Steffen Ruehl, Helene Seiler, Norbert Koch, Emil J. W. List-Kratochvil, Christoph T. Koch
Summary: 4D scanning transmission electron microscopy (4D-STEM) is a powerful technique that can characterize electron-transparent samples with high spatial resolution. By rastering an electron beam over a sample area and acquiring transmission diffraction patterns, 4D-STEM can provide detailed information about the atomic structure, crystallinity, orientation, and other properties of the sample. It can be used in scanning electron microscopes (SEMs) to study 2D materials and vdWH, with their inherently thin thickness. A unique 4D-STEM-in-SEM system is applied to reveal the single crystallinity of MoS2 exfoliated with gold-mediation and determine the crystal orientation and coverage of both components in a C60/MoS2 vdWH.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Sarah Gruetzmacher, Max Heyl, Marco Vittorio Nardi, Norbert Koch, Emil J. W. List-Kratochvil, Giovanni Ligorio
Summary: 2D transition metal dichalcogenides (TMDCs) are semiconductors with potential for optoelectronic applications, and their properties can be altered by chemically engineering the substrate surface. This study demonstrates local doping and adjustment of the electronic and optical properties of TMDCs (WSe2 and MoS2) by decorating the substrate with self-assembled monolayers (SAMs) with different molecular dipoles and dielectric constants. The interaction between SAMs and TMDCs leads to changes in the electronic band gap width, which can be predicted using the Schottky-Mott rule and knowledge of the dielectric screening effects. Understanding these effects allows for accurate prediction of TMDCs behavior for device design.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Fengshuo Zu, Dongguen Shin, Emilio Gutierrez-Partida, Martin Stolterfoht, Patrick Amsalem, Norbert Koch
Summary: The electronic properties of metal halide perovskites (MHPs) are crucial for optimal optoelectronic devices, but photoelectron spectroscopy (PES) measurements can be complex due to charge selective junctions and high-energy photons causing energy level realignment. Bremsstrahlung from twin-anode lab-sources can induce sizable shifts in core levels, whereas monochromatized X-ray lab-sources have minimal effects. These findings aim to enhance the reliability of PES measurements for obtaining accurate MHP electronic property information.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Ross Warren, Eunkyung Cho, Hong Li, Jean-Luc Bredas, Norbert Koch
Summary: This study addresses the failure of current models based on Fermi-Dirac statistics to explain the double ionization of dopants and bipolaron formation on a host polymer. By considering the renormalization of state energies upon electron transfer, the researchers provide insights and suggest that minimizing state energy renormalization is key to achieving double ionization of dopants or avoiding the formation of bipolarons on the host.
ACS MATERIALS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Ewa Wierzbicka, Thorsten Schultz, Karolina Syrek, Grzegorz Dariusz Sulka, Norbert Koch, Nicola Pinna
Summary: This study introduces a core-shell structure composed of nanostructured self-standing titania nanotubes filled with Au nanowire array, which shows efficient photocurrent generation and photon conversion efficiency for photoelectrocatalytic water splitting.
MATERIALS HORIZONS
(2022)
Article
Materials Science, Multidisciplinary
Jinfei Dai, Chenjing Zhao, Jie Xu, Hossein Roshan, Hua Dong, Francesco Di Stasio, Fang Yuan, Bo Jiao, Zhaoxin Wu
Summary: In this study, the performance of perovskite nanocrystal light emitting diodes (PNC-LEDs) was enhanced through rational device structure design and the application of high-performance perovskite nanocrystal emitting layers.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Jia-Hua Yeh, Suhendro Purbo Prakoso, Leon Lukhas Santoso, Shi-Ju Chen, Bryan Chiang, Ju-Chieh Cheng, Ru-Ning Zhang, Yu-Cheng Chiu
Summary: This study demonstrates the application of a renewable material called dextrin-SMS in the production of electret filters and transistor memory. Dextrin-SMS material can maintain prolonged electrostatic charges and has a relatively wide memory window, making it suitable for the production of biodegradable face masks and green electronics.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Ahmad Telfah, Qais M. Al-Bataineh, Ahmad A. Ahmad, Rund Abu-Zurayk, Carlos J. Tavares, Johannes Etzkorn, Farzad Foadian
Summary: Polyacrylic acid complexed with polyaniline (PAA/PANI) composite materials have the potential to form organic mixed ion-electron conductive (OMIEC) films, which can be used in optoelectronic and energy storage applications. The composite films are formed through an acid-base reaction, resulting in strong electrostatic interactions and intermolecular hydrogen bonds between PANI and PAA. The separation of PANI-rich domains from PAA-rich matrix in the composite films is observed. The electrical conductivity of the composite films is higher when the content of PANI is 33 wt%, due to the high ionic-electronic coupling at the interface between phase-separated regions.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Min-Chih Hou, Dian Luo, Yu-Ting Huang, Shun-Wei Liu, Chin-Wei Lu, Chih-Hao Chang, Hai-Ching Su
Summary: Light-emitting electrochemical cells (LECs) have great potential for novel emission applications, but their relatively low device efficiency hinders their competitiveness with other emission technologies. A study finds that increasing the concentration of small TiO2 nano-particles in the diffuser film can enhance light extraction and improve the device efficiency of LECs.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Qiaoli Niu, Yao Xu, Jun Yang, Wei Hua, Baoxiang Chai, Zequan Zhang, Yuhui Ma, Wenjin Zeng, Ana Flavia Nogueira, Ruidong Xia
Summary: By introducing CPB as a defect passivation agent in the perovskite precursor solution, the optoelectronic properties of perovskite films can be significantly improved and non-radiative carrier recombination can be effectively suppressed. CPB-modified perovskite solar cells exhibit lower trap-state density and stronger carrier migration capability, leading to enhanced power conversion efficiency and stability.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Hulya Ozturk Dogan, Fatma Yildirim, Zeynep Orhan, Ali Ben Ahmed, Mostefa Benhaliliba, Sakir Aydogan
Summary: In this study, efficient self-powered visible and UV photodetectors based on hybrid organic-inorganic materials were demonstrated. The photodetectors showed excellent UV detecting capability and good photoresponsivity.
ORGANIC ELECTRONICS
(2024)
