Article
Chemistry, Multidisciplinary
Shubham Tyagi, Paresh C. Rout, Ulrike Luders, Ulrich Eckern, Udo Schwingenschlogl
Summary: The electronic and magnetic properties of (LaCrO3)(m)/SrCrO3 superlattices are investigated using first principles calculations. It is found that the magnetization in the superlattices is dependent on the value of m, due to charge ordering with different oxidation states of Cr ions. The transparent p-type semiconductors with finite magnetization can be used to fabricate transparent magnetic diodes and transistors with potential technological applications.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Inorganic & Nuclear
Zhi-Cheng Wang, Kulatheepan Thanabalasingam, Jan P. Scheifers, Alenna Streeter, Gregory T. McCandless, Jonathan Gaudet, Craig M. Brown, Carlo U. Segre, Julia Y. Chan, Fazel Tafti
Summary: The crystal structure and magnetic properties of a new copper tellurite sulfate compound were analyzed, suggesting it as a promising alternative to layered perovskites for future experiments aiming to tune the Mott insulating ground state into superconducting or spin liquid states.
INORGANIC CHEMISTRY
(2021)
Article
Physics, Multidisciplinary
Loubaba Attou, Ahmed Al-Shami, Jaber Boujemaa, Omar Mounkachi, Hamid Ez-Zahraouy
Summary: Undoped and B-doped CaTiO3 semiconductor perovskite have been investigated using Density Functional Theory (DFT) and Boltzmann transport theory. B doping effectively reduces the electrical band gap and enhances visible light absorption ability. All doped structures show high absorbance and productive optical transition energy between 2 and 4 eV. Temperature-dependent transport characteristics favor undoped CaTiO3 at room temperature and B-doped CaTiO3 at elevated temperatures.
Article
Materials Science, Ceramics
Jong-Chan Lim, Changhyun Jin, Myung Sik Choi, Min Young Kim, Sang-il Kim, Soon-Mok Choi, Seung-Hyub Baek, Kyu Hyoung Lee, Hyun-Sik Kim
Summary: The research found that the response of Co-doped three-dimensional flower-like tungsten oxide nanoplates to ethanol gas sensing changes gradually according to the process temperature and Co doping concentration, influenced by a variety of complex factors. Therefore, in the field of ethanol gas sensing, analyzing various factors and predicting the results may be more important.
CERAMICS INTERNATIONAL
(2021)
Article
Engineering, Environmental
Jiaxuan Yin, Ning Wang, Chengliang Lin, Wei Liu, Seung-Taek Myung, Yongcheng Jin
Summary: Cobalt-free lithium-rich layered manganese-based oxides with excellent electrochemical performance and unique micro-porous structure were synthesized through a simple calcination process. The stability and reversibility of the lattice oxygen and oxygen vacancies in Al-doped LLMOs were enhanced by stronger Al-O bonding, and Al doping significantly affected the local transition metals coordination circumstance. The optimized LLMO-Al 0.075 cathode material exhibited high capacity, long cycling life, and improved stability.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Sanjayan Sathasivam, Sapna D. Ponja, Seonghyeok Park, Clara Sanchez-Perez, Christopher Blackman, Ivan P. Parkin, Claire J. Carmalt
Summary: Alternatives to tin-doped indium oxide transparent electrodes are required. Tungsten-doped SnO2 thin films with low resistivities and high electron mobilities were obtained using chemical vapor deposition. The tungsten dopant had minimal distortion to the SnO2 unit cell and resulted in crystallographic preferential orientation in the [200] direction. X-ray photoelectron spectroscopy analysis indicated that tungsten was present in the +5 state, minimizing ionized impurity scattering and achieving high electron mobilities. The tungsten-doped films had an optical band gap of 3.7 eV, making them transparent to visible light.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Crystallography
Yuma Fujita, Masanori Nagao, Yuki Maruyama, Satoshi Watauchi, Kazushi Miki, Isao Tanaka
Summary: Various Ir-doped beta-Ga2O3 single crystals were grown to investigate the solubility of Ir into the beta-Ga2O3 phase. Inclusion-free single crystals were obtained at a low doping concentration, while inclusions of Ir metal were observed at higher concentrations. The solubility of Ir in the beta-Ga2O3 phase was estimated to be 5.0 +/- 2.9 x 10(16) cm(-3) at a doping concentration of 5 x 10(-4).
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Chemistry, Inorganic & Nuclear
Dmitri O. Charkin, Artem S. Borisov, Vadim E. Kireev, Alexey N. Kuznetsov, Shorduz Umedov, Evgeny V. Nazarchuk, Vladimir N. Bocharov, Oleg I. Siidra
Summary: A new compound, Pb8O7I2, has been discovered in the oxygen-rich part of the PbO-PbI2 system. It can be prepared via solid-state and hydrothermal routes. The compound has a complex structure and exhibits high transparency in the 550-2000 nm range. Experimental and quantum chemical data indicate that it is a semiconductor with an approximate band gap of 2.6 eV.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Hwanhui Yun, Mehmet Topsakal, Abhinav Prakash, Bharat Jalan, Jong Seok Jeong, Turan Birol, K. Andre Mkhoyan
Summary: A metallic line defect with distinct atomic structure composed of Sn and O atoms was found in optically transparent BaSnO3 perovskite thin films. Doping with La caused dopants to preferentially segregate to specific crystallographic sites adjacent to the line defect. The electronic structure of the line defect probed in STEM with electron energy-loss spectroscopy was supported by ab initio theory, indicating the presence of Fermi level-crossing electronic bands originating from defect core atoms.
Article
Energy & Fuels
John O'Sullivan, Matthew Wright, Xinya Niu, Poppy Miller, Peter R. Wilshaw, Ruy S. Bonilla
Summary: This work proposes a novel transparent conducting electrode (TCE) based on electrostatically doped graphene monolayers to overcome the limitations of indium-based TCEs in perovskite/silicon tandem cells. The electrode utilizes a thin film dielectric charged and interfaced to a graphene film, allowing for modulation of charge carriers in graphene through electrostatic doping. Experimental results demonstrate that short-duration dielectric charging can significantly reduce the sheet resistance of graphene without impacting the transmission of light. The deposition of negative electrostatic charge enables precise tuning of charge concentration from n-type to p-type.
PROGRESS IN PHOTOVOLTAICS
(2023)
Article
Materials Science, Ceramics
Amr Attia Abuelwafa, M. S. Abd El-sadek, Sahar Elnobi, Tetsuo Soga
Summary: SnO thin films were deposited on ITO, FTO, and glass substrates using thermal evaporation technique, revealing amorphous structure and direct transitions in Tauc's relation. The study found that SnO/ITO exhibited higher nonlinear parameters compared to SnO/FTO, suggesting potential in nonlinear optics applications.
CERAMICS INTERNATIONAL
(2021)
Article
Optics
Chaoquan Hu, Zijian Zhou, Xiaoyu Zhang, Kaiyu Guo, Can Cui, Yuankai Li, Zhiqing Gu, Wei Zhang, Liang Shen, Jiaqi Zhu
Summary: The challenge in designing far-infrared transparent conductors (FIRTC) is to achieve both high plasma absorption edge (λp) and high conductivity (o). This paper breaks the trade-off between high conductivity and plasma absorption edge by increasing the neglected constant εopt, and successfully develops the material family of FIRTC with εopt > 15 and λp > 15 μm. These FIRTC materials are mainly octahedrally-coordinated heavy-metal chalcogenides and their solid solutions with shallow-level defects, which exhibit a high εopt due to the formation of electron-deficiency multicenter bonds resulting in the great electron-polarization effect. The development of FIRTC opens up new possibilities for far-infrared optoelectronics.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Chemistry, Physical
Hui Xu, Kun Wang, Lei Jin, Lida Yang, Jingjing Yuan, Wenyao Zhang, Guangyu He, Haiqun Chen
Summary: An advanced approach of incorporating Ru dopants and sulfur vacancies into FeNi2S4 catalyst has been proposed to synergistically modulate the electronic configuration, leading to the formation of active Ni3+ species. The optimized Ru-FeNi2S4 catalyst exhibits superb electrocatalytic performance towards oxygen evolution reaction (OER), delivering low overpotentials in alkaline water and seawater.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Engineering, Environmental
Lingxia Zheng, Yijian Zhao, Penghui Xu, Yujuan Zhao, Zhuoqing Lv, Weiqing Ye, Xiaowei Shi, Qi Wu, Huajun Zheng
Summary: Electronic structure engineering is essential for developing efficient electrocatalysts. By introducing Fe dopants and oxygen vacancies, a defective CoOx-V-o-D-Fe catalyst was synthesized, showing excellent catalytic activity for oxygen evolution reaction (OER). The combination of Fe doping, oxygen defect engineering, and the formation of hetero-interfaces synergistically tuned the electronic configuration, resulting in decreased binding energy of OOH* and much lower overpotential. This study provides a strategy for enhancing the activity of electrocatalysts for various electrochemical energy devices.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Yujuan Zhang, Mingyu Wu, Zhihang Wang, Ningning Zhang, Changchun Ge
Summary: Theoretical study on electronic band structure modulation of Hf2CO2 MXene through substitution doping shows that dopants at different sites lead to varying properties from semiconductor to metallic, with p states playing a significant role in the process. Negative solution energy and binding energy suggest the feasibility of doping technique for engineering band gaps of MXene materials.
JOURNAL OF MATERIALS RESEARCH
(2021)
Article
Chemistry, Physical
Yong-Seok Choi, Sara I. R. Costa, Nuria Tapia-Ruiz, David O. Scanlon
Summary: The development of high-power anode materials for Na-ion batteries is hindered by the low electrical conductivity and poor structural stability of Na2Ti3O7. Approaches such as aliovalent doping and hydrogenation/hydrothermal treatments have been proposed to overcome these drawbacks, but the intrinsic defect chemistry of Na2Ti3O7 is still not well understood. This study employs hybrid density functional theory calculations to investigate the native defect chemistry of Na2Ti3O7 and provides insights on the interplay between defects, structural phase transitions, and electrical conductivity.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Irea Mosquera-Lois, Sean R. Kavanagh, Aron Walsh, David O. Scanlon
Summary: Point defects are common features in crystals, and their identification is usually achieved through a combination of experimental measurements and theoretical models. However, the standard modelling approach often fails to consider energy-lowering reconstructions from the ideal crystallographic environment, resulting in missed ground state atomic configurations and compromised accuracy of calculated properties. To overcome this issue, we propose an approach that utilizes targeted bond distortions and rattling to navigate the defect configurational landscape. Applying this method to eight different materials reveals symmetry breaking in each host crystal that conventional local minimisation techniques fail to capture. The point defect distortions are classified based on their associated physico-chemical factors, and their impact on derived properties such as formation energies, concentrations, and charge transition levels is demonstrated. This work represents a significant advancement towards quantitative modelling of imperfect solids.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Danny Broberg, Kyle Bystrom, Shivani Srivastava, Diana Dahliah, Benjamin A. D. Williamson, Leigh Weston, David O. Scanlon, Gian-Marco Rignanese, Shyam Dwaraknath, Joel Varley, Kristin A. Persson, Mark Asta, Geoffroy Hautier
Summary: Calculations of point defect energetics with DFT methods provide valuable insight into various properties. This work compares automated, semi-local point defect calculations with a-posteriori corrections to gold standard hybrid calculations. The study evaluates qualitative and quantitative differences in defect information and highlights the potential and limits of high-throughput calculations based on semi-local DFT methods.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Energy & Fuels
Jiayi Cen, Bonan Zhu, David O. Scanlon
Summary: In this study, ab initio random structure searching (AIRSS) was used to accelerate materials discovery of the Li-Ni-O phase space. The study discovered structures (such as LiNiO2) displaying dynamic Jahn-Teller effects and a thermodynamically stable Li2Ni2O3 phase. Additionally, many dynamically stable structures close to the convex hull were encountered, confirming the presence of metastable Li-Ni-O phases and revealing their structures and properties. This work will facilitate the identification of Li-Ni-O phases in future experiments and address the challenges in synthesizing these phases.
JOURNAL OF PHYSICS-ENERGY
(2023)
Article
Chemistry, Multidisciplinary
Bastien F. Grosso, Daniel W. Davies, Bonan Zhu, Aron Walsh, David O. Scanlon
Summary: Building on previous research on metal oxide and metal halide perovskites, this study focuses on the largely unexplored realm of metal nitride perovskites. Through extensive computational screening, the researchers predict 12 stable nitride perovskite materials with significant electric polarization and low predicted switching electric field, making them attractive for ferroelectric memory devices. Promising compositions include YMoN3, YWN3, ZrTaN3, and LaMoN3.
Article
Chemistry, Physical
Katarina Brlec, Christopher N. Savory, David O. Scanlon
Summary: Utilising photocatalytic water splitting is crucial for producing green hydrogen and reducing the carbon footprint of this important chemical feedstock. This study employs density functional theory (DFT) to gain insights into the photocatalytic performance of a promising photocatalyst, Y2Ti2O5S2, from first principles. The study evaluates eleven non-polar clean surfaces at the generalised gradient approximation level and further considers the (001), (101), and (211) surfaces at the hybrid-DFT level to determine their band alignments. The study also establishes relevant optoelectronic bulk properties using a combination of hybrid-DFT and many-body perturbation theory.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Physical
Adair Nicolson, Sean R. Kavanagh, Christopher N. Savory, Graeme W. Watson, David O. Scanlon
Summary: Copper-chalcogenides are prospective materials for thin film solar cells due to their desirable electronic properties and defect tolerance. In this study, we investigate the optoelectronic properties of Cu2SiSe3 and find that it exhibits a direct bandgap of 1.52 eV and a maximum efficiency of 30% for a 1.5 μm-thick film at the radiative limit. The formation energies of intrinsic defects are calculated, revealing that the dominant defect species is the p-type copper vacancy, which forms a perturbed host state. Overall, we propose further investigation of Cu2SiSe3 as a potential defect-tolerant photovoltaic absorber.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Materials Science, Multidisciplinary
Luisa Herring Rodriguez, Kieran B. Spooner, Maud Einhorn, David O. Scanlon
Summary: This study investigates the thermoelectric properties of the ternary wide band semiconductor Sr2Sb2O7, which has high thermal stability and shows potential as a high-performance n-type oxide thermoelectric. The maximum ZT value of 0.71 at 1400K was obtained when the material was nanostructured to 10 nm.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Alexander G. Squires, David O. Scanlon
Summary: Suppressing short-range ordering in disordered rock salt lithium-ion cathode materials is important for their commercialization. This study investigates the effect of many-component cation substitution on the suppression of short-range ordering using cluster-expansion-driven Monte Carlo simulations. The results show that many-cation substitution is effective in suppressing short-range ordering, but its effectiveness decreases with an increase in the number of transition metals or the size of the lithium diffusion network.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Physical
Jiayi Cen, Bonan Zhu, Sean R. Kavanagh, Alexander G. G. Squires, David O. O. Scanlon
Summary: By modifying synthesis conditions, the ordered arrangement of LiMn1.5Ni0.5O4 can be tuned, but it also affects the oxygen and Mn3+ stoichiometries, making it difficult to optimize performance. This study investigates all intrinsic defects in P4(3)32 LMNO and finds that majority of defects are associated with small polarons formation. The tendency for cation disorder can be explained by the low formation energy of the antisite defects and their stoichiometric complexes. The intrinsic Fermi level of LMNO varies under different oxygen conditions. This work provides insights for defect-controlled synthesis and explains experimental observations.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Physical
Zilu Liu, Md Azimul Haque, Chris N. Savory, Tianjun Liu, Satoru Matsuishi, Oliver Fenwick, David O. Scanlon, Martijn A. Zwijnenburg, Derya Baran, Bob C. Schroeder
Summary: Poly(nickel-benzene-1,2,4,5-tetrakis(thiolate)) (Ni-btt) and poly(nickel-benzene-1,2,3,4-tetrakis(thiolate)) (Ni-ibtt) are isomers with different backbone geometries. Ni-ibtt exhibits slightly higher solubility and an increased bandgap compared to Ni-btt. The most significant difference lies in their thermoelectric properties, with Ni-btt showing p-type behavior and Ni-ibtt demonstrating n-type carrier characteristics.
FARADAY DISCUSSIONS
(2023)
Article
Materials Science, Multidisciplinary
Xinwei Wang, Sean R. Kavanagh, David O. Scanlon, Aron Walsh
Summary: The study reveals the phenomenon of negative-U behavior in Sb2Se3, where a defect traps a second charge carrier more strongly. Utilizing a global structure searching strategy, the researchers found large atomic reconfigurations that facilitate charge redistribution. Thermodynamic analysis shows a four-electron negative-U transition for both VSe and VSb, indicating that all intrinsic point defects in Sb2Se3 exhibit amphoteric behavior.
Article
Chemistry, Multidisciplinary
Carla Casadevall, Ava Lage, Manting Mu, Heather F. Greer, Daniel Anton-Garcia, Julea N. Butt, Lars J. C. Jeuken, Graeme W. Watson, Max Garcia-Melchor, Erwin Reisner
Summary: By using gel filtration size exclusion chromatography, successful size separation of carbon dots was achieved, and the effect of size on their photocatalytic performance was studied. The study found that monodisperse carbon dots exhibited higher activity in photocatalytic H2 evolution compared to the synthesized polydisperse samples.
Article
Chemistry, Multidisciplinary
Carla Casadevall, Ava Lage, Manting Mu, Heather F. Greer, Daniel Anton-Garcia, Julea N. Butt, Lars J. C. Jeuken, Graeme W. Watson, Max Garcia-Melchor, Erwin Reisner
Summary: This study investigates the performance of carbon dots (CDs) of different sizes in a photocatalytic system. Gel filtration size exclusion chromatography successfully separates the monodisperse CDs. The experiment demonstrates that the monodisperse CDs exhibit higher activity in photocatalytic hydrogen evolution compared to the polydisperse samples. This research reveals the size-dependent effect of CDs on photocatalytic performance.
