Article
Nanoscience & Nanotechnology
Gaukhar Askarova, Mahdi Hesari, Koushik Barman, Michael V. Mirkin
Summary: Using photoscanning electrochemical microscopy, the overall water splitting phenomenon of phosphorus-doped BiVO4 microcrystals was visualized for the first time, and the local oxygen and hydrogen fluxes were successfully measured. This study is significant for understanding the activity of photocatalysts.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Xin Sun, Min Wang, Qi Geng, Shuailin Chen, Xiaojun Lv, Xunlei Ding, Meicheng Li
Summary: This study demonstrates the use of aluminum ferrite (AFO) as a stable solar absorber in photoelectrochemical cells, showcasing its attractive performance. AFO thin-film photoelectrodes composed of vertically oriented nanosheets exhibit a photocurrent density of +0.78 mA.cm(-2) at 1.23 V vs. RHE, with a U-onset close to the flat band potential of 0.5 V vs. RHE in the presence of hole scavengers. AFO also exhibits rare coincidence between U-onset and flat band potential for solar water splitting, along with other favorable optoelectronic properties and carrier lifetimes, suggesting its great potential for photoelectrochemical cell applications.
Article
Chemistry, Physical
Motoki Osada, Kazunori Nishio, Kyuho Lee, Michael Colletta, Berit H. Goodge, Woo Jin Kim, Lena F. Kourkoutis, Harold Y. Hwang, Yasuyuki Hikita
Summary: The research presents the first photoelectrochemical characterization of epitaxial thin film Fe2TiO5, revealing highly efficient charge transfer at the Fe2TiO5-electrolyte interface. This notable surface property is exploited in the form of an Fe2TiO5/alpha-Fe2O3 heterostructure photoanode, leading to a significant increase in photocurrent density and improvement in onset potential.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Stuart R. Burns, Alexander Tselev, Anton V. Ievlev, Joshua C. Agar, Lane W. Martin, Sergei V. Kalinin, Daniel Sando, Petro Maksymovych
Summary: Ferroelectric thin films demonstrate tunable microwave frequency electronic response through domain walls, opening up possibilities for ferroelectric memristors or volatile resistive switches operating at the nanoscale with well-defined dynamics. The mechanism behind tunable microwave conductivity is found to be the variable area of the domain wall within the switching volume.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Md Maidul Islam, Daniel G. Georgiev
Summary: The Cu3N films were deposited through reactive sputtering of copper in a nitrogen/argon gas mixture, with the resulting films exhibiting polycrystalline structure and variable crystalline orientation depending on substrate temperature. The optical band gap values and resistivity of the film material showed significant variations with substrate temperature and nitrogen gas fraction, with different characteristics observed for films deposited on Si and glass substrates.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Chemistry, Physical
Hafiza Komal Zafar, Manzar Sohail, Ayman Nafady, Kostya Ken Ostrikov, Geoffrey Will, Md A. Wahab, Anthony P. O'Mullane
Summary: The use of fossil fuels poses a threat to the Earth's climate and its inhabitants. Photoelectrochemical water splitting has emerged as a promising solution to produce oxygen and hydrogen in a cost-effective and environmentally friendly manner. This study presents the development of S-doped Cu3Se2 thin films using a chemical bath deposition process to enhance PEC water oxidation efficiency.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Rubem Caetano, Astrid Ali, Jade Barreto, Guilherme Felix, Maria I. Ramos, Braulio S. Archanjo, Carlos A. Achete, Emilia Annese, Fernando Stavale
Summary: This study examines the structure of Mn3O4 (110) thin films and finds that the surface contains both Mn3+ and Mn2+ ions, which contribute to its catalytic activity. The film surface has a fully oxidized layer of Mn2+ and Mn3+ ions at the interface with Cu metal.
Article
Chemistry, Multidisciplinary
Yongzhen Luo, Xidong Ding, Tianci Chen, Guocong Lin, Tao Su, Dihu Chen
Summary: The method of imaging permittivity of thin film materials using a scanning capacitance microscope (SCM) provides a novel approach with nanometer resolution for studying photoelectric materials under room temperature atmospheric conditions.
APPLIED SCIENCES-BASEL
(2022)
Article
Nanoscience & Nanotechnology
Jiachen Sun, Nestor Guijarro, Peihang Li, Udayabhaskararao Thumu, Jun-Ho Yum, Kevin Sivula, Zhiming M. M. Wang
Summary: Photoelectrochemical water splitting and CO2 reduction reaction is a promising method for addressing energy and environment issues. Research has shown that a modified solution process can enhance crystal size and improve performance and output current by reducing surface ligands. Deposition of gold nanoparticles on CIGS surface can achieve a Faradic efficiency of 12.93% in aqueous electrolytes and 25% in nonaqueous electrolytes for CO2-to-CO conversion. Further investigation reveals that the CIGS photocathode displays stable photocurrent density within a certain applied potential range, but significant current degradation occurs at higher applied bias. Coupling catalysts with CIGS enhances selectivity towards CO and reduces competitive hydrogen evolution reaction.
ACS APPLIED NANO MATERIALS
(2023)
Article
Energy & Fuels
Hongyu Qu, Xiaoyu Xu, Longfei Hong, Xintie Wang, Yifei Zan, Huiyan Zhang, Xiao Zhang, Sheng Chu
Summary: This study reported the synthesis of uniform PI photoelectrode films via a simple spin-coating method and investigated the influence of the conjugate size of electron acceptor on PEC performance. The naphthalene-based PI photoelectrode exhibited the highest photocurrent response.
FRONTIERS IN ENERGY
(2023)
Article
Nanoscience & Nanotechnology
Mengjun Wu, Fei Sun, Xintong Wang, Xiaoyue Zhang, Weijin Chen, Yue Zheng
Summary: This work reports a facile control of ferroelastic domain patterns in BiFeO3 thin films by exploiting the tip bias as the control parameter. By controlling the scanning tip bias, mesoscopic topological defects can be readily written into the films without the necessity to change the tip motion. The correlation between conductance of the scanned region and the switching pathway is further investigated.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
K. Hlushko, T. Ziegelwanger, M. Reisinger, J. Todt, M. Meindlhumer, S. Beuer, M. Rommel, I. Greving, S. Flenner, J. Kopeck, J. Keckes, C. Detlefs, C. Yildirim
Summary: In order to understand the effects of thermomechanical fatigue on Cu metallization used in power electronics, the intragranular microstructure and strain evolution within individual Cu grains and near grain boundaries were assessed using synchrotron dark field X-ray microscopy (DFXM). The results showed severe shear deformation of Cu grains, surface roughening of the film, gradual grain refinement, and the formation of microscopic voids near high angle grain boundaries (HAGBs). The study also identified the condensation of structural defects near HAGBs as a driving force for void formation.
Article
Electrochemistry
Akhilender Jeet Singh, Garima Aggarwal, Chandan Das, K. R. Balasubramaniam
Summary: Nanostructured light absorbers in PEC devices offer improved charge carrier collection and increased active area compared to planar structures. A simple two-step electrochemical treatment is described to obtain nanostructured Cu2O films, showing significant enhancement in photocurrent over dense Cu2O. Reconstruction of the dense film into a nano-walled structure is achieved through voltage cycling, resulting in phase pure nanostructured films with features as small as 10 nm.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Materials Science, Multidisciplinary
Chih-Jui Chang, Chih-Wei Lai, Wei-Cheng Jiang, Yi-Syuan Li, Changsik Choi, Hsin-Chieh Yu, Shean-Jen Chen, YongMan Choi
Summary: In this study, CuO thin films were prepared using the sol-gel spin coating method, and electrodeposition was applied to fabricate Cu2O thin films to investigate the effects of aging time and layer dependency. The fully oxidized CuO thin films exhibited higher efficiency in photoconversion compared to Cu2O thin films.
Article
Engineering, Environmental
Xiang Cheng, Libin Ji, Yingying Bi, Wei Wang, Shutao Gao, Huiliang Li, Ningzhao Shang, Wei Gao, Chenchen Feng, Chun Wang
Summary: This study presents a simple hydrothermal method to self-assemble metal-organic coordination networks on BiVO4, significantly improving the photoelectrochemical (PEC) water oxidation activity and stability. The metal-organic coordination networks prevent photocorrosion of BiVO4 and provide abundant active sites to decrease the overpotential and accelerate the reaction kinetics. The BiVO4/photoanode with metal-organic coordination networks exhibits outstanding photocurrent density and long-term stability, offering a potential pathway for building efficient and stable PEC water splitting systems.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Matthias Kuhl, Alex Henning, Lukas Haller, Laura Wagner, Chang-Ming Jiang, Verena Streibel, Ian D. Sharp, Johanna Eichhorn
Summary: Plasma-enhanced atomic layer deposition can be used to tune the structure and properties of cobalt hydroxide films by controlling the plasma exposure time and power. Short exposure times and low powers result in highly porous and catalytically active films with poor electrochemical stability, while long exposure times and high powers improve crystallinity and electrochemical stability but reduce catalytic activity. By using the former as the surface layer and the latter as the interface layer, bilayer films with both high catalytic activity and electrochemical stability can be obtained.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Min Wang, Anna Loiudice, Valery Okatenko, Ian D. D. Sharp, Raffaella Buonsanti
Summary: The coupling of CO-generating molecular catalysts with copper electrodes in tandem schemes is a promising strategy to boost the formation of multi-carbon products in the electrocatalytic reduction of CO2. The spatial distribution of the two components in molecular-based tandem systems has not been well explored. This study examines the importance of the relative spatial distribution of Co-phthalocyanine (CoPc) and Cu nanocubes (Cu-cub) on the performance of tandem catalysts. It is found that a direct contact between the CO-generating molecular catalyst and the Cu is crucial for promoting C-C coupling, indicating a surface transport mechanism between the two components of the tandem catalyst.
Article
Chemistry, Multidisciplinary
Alex Henning, Johannes D. Bartl, Lukas Wolz, Maximilian Christis, Felix Rauh, Michele Bissolo, Theresa Grunleitner, Johanna Eichhorn, Patrick Zeller, Matteo Amati, Luca Gregoratti, Jonathan J. Finley, Bernhard Rieger, Martin Stutzmann, Ian D. Sharp
Summary: Atomic layer deposition (ALD) is a crucial technique for scaling semiconductor devices, but achieving atomically-defined coatings and surface modifications is challenging. This study presents a method for depositing sub-nanometer thin and continuous aluminum oxide (AlOx) coatings on silicon substrates, allowing spatial control of surface charge density and interface energetics. Using trimethylaluminum and remote hydrogen plasma, silicon dioxide (SiO2) is transformed into alumina. The resulting patterned surfaces possess lateral AlOx/SiO2 interfaces with precise step heights and surface potential steps, enabling modulation of surface band bending.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Andrii Shcherbakov, Kevin Synnatschke, Stanislav Bodnar, Jonathan Zerhoch, Lissa Eyre, Felix Rauh, Markus W. Heindl, Shangpu Liu, Jan Konecny, Ian D. Sharp, Zdenek Sofer, Claudia Backes, Felix Deschler
Summary: Layered van der Waals (vdW) antiferromagnets with low-dimensional excitonic properties and complex spin-structure are promising materials for future opto-spintronic applications. In this study, we successfully fabricated centimeter-scale thin films of the 2D antiferromagnetic material NiPS3 using liquid phase exfoliation. The films showed antiferromagnetic spin arrangement, spin-entangled Zhang-Rice multiplet excitons, and ultranarrow emission line widths, despite their disordered nature. These results demonstrate the scalable thin-film fabrication of high-quality NiPS3, which is crucial for utilizing this material in spintronic and nanoscale memory devices and exploring its complex spin-light coupled states.
Article
Chemistry, Physical
Pan Ding, Hongyu An, Philipp Zellner, Tianfu Guan, Jianyong Gao, Peter Mueller-Buschbaum, Bert M. Weckhuysen, Ward van der Stam, Ian D. Sharp
Summary: This study investigates the impact of catalyst ink formulation on CO2 electrolysis and finds that Nafion is essential for achieving stable product distributions. The content of Nafion and the solvent composition regulate the internal structure of Nafion coatings and the catalyst morphology, thus significantly impacting CO2 electrolysis performance.
Article
Chemistry, Physical
Hojoong Choi, Young Yun Kim, Sehun Seo, Yoonsung Jung, So-Min Yoo, Chan Su Moon, Nam Joong Jeon, Sanseong Lee, Kwanghee Lee, Francesca M. Toma, Jangwon Seo, Sanghan Lee
Summary: Reported is a high-efficiency organometal halide perovskite (OHP)-based photoanode with a rational design that suppresses undesired losses, such as non-radiative recombination of carriers and sluggish reaction kinetics. The rational design includes defect-passivated electron transport layers to suppress undesired recombination, and Fe-doped Ni3S2 with high catalytic activity to promote PEC water oxidation and suppress losses at OHP/electrolyte interface. The fabricated Fe-doped Ni3S2/Ni foil/OHP photoanodes achieved a remarkable applied bias photon-to-current efficiency of 12.79%, the highest among previously reported OHP-based photoanodes by suppressing undesired losses.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Alex Henning, Sergej Levashov, Chenjiang Qian, Theresa Gruenleitner, Julian Primbs, Jonathan J. Finley, Ian D. Sharp
Summary: It is demonstrated that in situ spectroscopic ellipsometry (SE) is a powerful method for optimizing film growth and opto(electronic) characteristics of 2D materials during atomic layer deposition (ALD). By utilizing in situ SE during ALD on monolayer MoS2, a low temperature process for encapsulating the 2D material with a nanometer-thin alumina (AlOx) layer is investigated, which results in a 2D/3D interface controlled by van der Waals interactions. The charge transfer doping of MoS2 by AlOx is found to be an interfacial phenomenon that initiates from the earliest stages of film formation.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Laura I. Wagner, Elise Sirotti, Oliver Brune, Gabriel Groetzner, Johanna Eichhorn, Saswati Santra, Frans Munnik, Luca Olivi, Simone Pollastri, Verena Streibel, Ian D. Sharp
Summary: The performance of Ta3N5 as a photoanode for solar water splitting can be greatly enhanced by controlled Ti doping, resulting in reduced deep-level defects, increased photocurrent density, and shifted photocurrent onset potential. Ti4+ ions substitute Ta5+ lattice sites, reducing the concentrations of harmful nitrogen vacancies and Ta3+ states, thereby suppressing trapping and recombination. Ti doping also allows for tuning of electrical conductivity without increasing the oxygen donor content.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Vivien L. Cherrette, Finn Babbe, Jason K. Cooper, Jin Z. Zhang
Summary: Exciton-phonon interactions are found to cause broadening of photoluminescence line width and slower electron-hole recombination in cubic CsPbBr3 perovskite quantum dots (PQDs) due to structural distortions at room temperature. At low temperature, phonon-assisted recombination is reduced, resulting in minimized line width broadening.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Instruments & Instrumentation
F. Rauh, O. Bienek, I. D. Sharp, M. Stutzmann
Summary: The necessity for higher sample throughput has led to an increase in the use of robotic systems and automation in sample preparation processes. This study presents a low-cost alternative to commercial dip coaters by using a readily available 3D printer and compares the resulting films to those obtained from a commercial device. The 3D printer-based device allows for automated dip coating processes using multiple dipping solutions for a batch of samples, potentially saving time and cost compared to commercial systems. The film quality achieved by the home-built system is comparable, and sometimes even better in terms of uniformity and roughness, making it a viable alternative to commercial dip coating devices.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Nanoscience & Nanotechnology
Oliver Bienek, Benedikt Fuchs, Matthias Kuhl, Tim Rieth, Julius Kuhne, Laura I. Wagner, Lina M. Todenhagen, Lukas Wolz, Alex Henning, Ian D. Sharp
Summary: III-V compound semiconductors have optoelectronic properties suitable for solar energy conversion. This study investigates the impact of defects in atomic layer deposition of titanium oxide (TiOx) on junction formation, interfacial charge transport, and photocarrier recombination. The results show that defect concentrations in TiOx can be controlled to modulate optical constants, electrical conductivity, and interface chemistry, allowing for tuning of junction formation and achieving high photovoltage photocathodes.
Article
Chemistry, Physical
Marcella Bonchio, Julien Bonin, Osamu Ishitani, Tong-Bu Lu, Takeshi Morikawa, Amanda J. Morris, Erwin Reisner, Debashrita Sarkar, Francesca M. Toma, Marc Robert
Summary: Visible-light-driven conversion of CO2 to fuels and valuable compounds has been highly active in recent years. However, these processes and catalytic systems are still in early stages of development, with fundamental mechanistic challenges needing to be addressed. Collaborative efforts are needed to explore various approaches and establish robust practices to advance our understanding of these necessary processes.
Article
Chemistry, Multidisciplinary
Chanyeon Kim, Alex J. King, Shaul Aloni, Francesca M. Toma, Adam Z. Weber, Alexis T. Bell
Summary: Photoelectrochemical carbon-dioxide reduction (PEC CO2R) is a promising method for producing chemicals and fuels using sunlight, water, and carbon dioxide. However, the focus has been mostly on producing C-1 products, while the production of C2+ products has been rarely demonstrated. In this study, a Cu/TiO2/p-Si photocathode/catalyst structure was investigated to understand the effects of semiconductor-insulator interactions and illumination direction on the performance and product distribution. Coating the Cu surface with a thin bilayer of Sustainion/Nafion significantly enhanced the current density and faradaic efficiency to ethylene.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Min Wang, Vasilis Nikolaou, Anna Loiudice, Ian D. Sharp, Antoni Llobet, Raffaella Buonsanti
Summary: Copper-based tandem schemes are promising strategies to enhance multi-carbon product formation in the electrocatalytic CO2 reduction reaction. By coupling a CO-generating catalyst with copper nanocatalysts, the selectivity for ethylene production can be significantly increased.