Article
Materials Science, Multidisciplinary
Yuan Zhi Zhang, Shuai Ling Li, Zhen Li, Shi Yun Lou, Shao Min Zhou
Summary: By introducing Sn doping, the GeTe-based material forms a disordered structure, resulting in reduced thermal conductivity and improved thermoelectric performance.
Article
Nanoscience & Nanotechnology
Masatake Tsuji, Soshi Iimura, Junghwan Kim, Hideo Hosono
Summary: Copper iodide (CuI) is a transparent semiconductor with excellent carrier mobility, but its high hole concentration limits its applicability in thin-film transistors. We found that Zn substitution into Cu+ sites effectively reduces the hole concentration through the formation of a defect pair and the stabilization of Cu+ in the lattice structure of Zn-substituted CuI. Our results show that the hole concentration of Zn-substituted CuI can be tuned in a range suitable for thin-film transistors and hole transport layers in OLEDs.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Daisuke Kato, Kouta Iwasaki
Summary: The control of Mg content in Mg2Si-based thermoelectric materials is crucial for tuning the carrier concentration. Through Mg-pressure-controlled annealing, precise control of Mg content was achieved in Mg2-delta(Si0.5Sn0.5)(1-x)Sb-x, demonstrating the impact of Mg content on carrier concentration, Seebeck coefficient, and zT values.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Computer Science, Interdisciplinary Applications
Joel Davidsson, Viktor Ivady, Rickard Armiento, Igor A. Abrikosov
Summary: ADAQ is an automatic workflow collection developed for high-throughput simulations of magneto-optical properties of point defects in semiconductors, handling a vast number of defects by automating processes and outputting relevant properties. The paper demonstrates the capability of ADAQ by studying the silicon vacancy in silicon carbide as an example.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Chemistry, Physical
P. Bag, Y. H. Lin, Y. K. Kuo, C. N. Kuo, C. S. Lue
Summary: We report the physical properties of a series of Ru2-xFexNbAl (x = 0.0 0-0.50) alloys, including magnetization, electrical resistivity, Seebeck coefficient, and thermal conductivity measurements. The Fe substitution changes the conduction behavior of the Ru2NbAl alloy, leading to a shift in the minimum resistivity and modification of the electronic band structure. Fe substitution also significantly reduces thermal conductivity through the increase of grain boundaries, Umklapp phonons, and electron scatterings. These observations result in an increase in the thermoelectric performance for the optimized composition of Fe with x = 0.13. (c) 2023 Elsevier B.V. All rights reserved.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Condensed Matter
Michael Alexander Reshchikov, Mykhailo Vorobiov, Oleksandr Andrieiev, Benjamin McEwen, Emma Rocco, Vincent Meyers, Denis O. Demchenko, F. Shadi Shahedipour-Sandvik
Summary: A systematic study of photoluminescence in Be-doped GaN grown by metal-organic chemical vapor deposition reveals the presence of ultraviolet and yellow luminescence bands, attributed to the shallow and polaronic states of the Be-Ga acceptor, respectively. The yellow luminescence band exhibits a unique two-step thermal quenching behavior.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Chemistry, Physical
Allison Wustrow, Guanglong Huang, Matthew J. McDermott, Daniel O'Nolan, Chia-Hao Liu, Gia Thinh Tran, Brennan C. McBride, Shyam S. Dwaraknath, Karena W. Chapman, Simon J. L. Billinge, Kristin A. Persson, Katsuyo Thornton, James R. Neilson
Summary: The study identified a cooperative effect in solid-state metathesis reactions that involves using alkaline earth metals instead of alkali metals to lower the formation temperature of orthorhombic YMnO3. Experiments showed that by reacting MgMn2O4 and CaMn2O4 with YOCl in a cooperative cometathesis reaction, reaction temperatures can be reduced to 550°C while maintaining phase selectivity. This approach also showed potential in synthesizing other metastable targets such as TbMnO3, ErMnO3, and DyMnO3 with reduced temperatures and preserved reaction selectivity.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Physical
Smobin Vincent, Jin Hyun Chang, Pieremanuele Canepa, Juan Maria Garcia-Lastra
Summary: Rechargeable Mg-S batteries are attractive due to their high energy density and low costs. The poor cycling performance of Mg-S batteries is linked to the formation of insulating discharge products, but our research suggests that by controlling the oxidation process, the batteries can be improved.
CHEMISTRY OF MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Galina M. Kuz'micheva, Liudmila I. Ivleva, Irina A. Kaurova, Evgeny Khramov, Victor B. Rybakov, Maxim E. Doroshenko
Summary: Calcium orthovanadate single crystals doped with manganese were studied, revealing Mn3+ ions and vacancies at different sites; proposed models for the rearrangement of polyhedra; observed different oxidation states of manganese ions through optical spectroscopy.
MATERIALS RESEARCH BULLETIN
(2021)
Article
Chemistry, Multidisciplinary
Manoj Tripathi, Frank Lee, Antonios Michail, Dimitris Anestopoulos, James G. McHugh, Sean P. Ogilvie, Matthew J. Large, Aline Amorim Graf, Peter J. Lynch, John Parthenios, Konstantinos Papagelis, Soumyabrata Roy, M. A. S. R. Saadi, Muhammad M. Rahman, Nicola Maria Pugno, Alice A. K. King, Pulickel M. Ajayan, Alan B. Dalton
Summary: This study investigates the influence of different geometries of line defects in graphene and molybdenum disulfide using atomic force microscopy and Raman spectroscopic mapping. The stiffness of graphene was found to be higher than molybdenum disulfide, with deflated graphene nanobubbles exhibiting the lowest stiffness. Density functional theory reveals alteration of bandstructures in graphene and MoS2 due to wrinkled structures, showing a higher modulation effect in MoS2.
Article
Materials Science, Multidisciplinary
N. Mishra, G. Makov
Summary: The energetic and electronic properties of point defects in lead sulfide were studied using first-principles methods. A novel, stable interstitial site was identified, with lead vacancies found to have the lowest formation energies in S-rich conditions and sulfur vacancies in Pb-rich conditions.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Physics, Condensed Matter
Yang Xu, Tao Li, Changyi Hu, Shenggang Zhou, Yan Wei, Xian Wang, Yong Cao
Summary: The thermodynamic properties of TiB with different defects and dopants, including B-vacancy, Ti-vacancy, V-substitutional, and V-interstitial doping under high temperature and high pressure, were systematically analyzed using first-principles calculations. The presence of vacancies led to a decrease in volume, while V doping caused lattice distortion and affected supercell volume. The constant volume heat capacity of TiB increased with temperature and approached the Dulong-Petit limit, while the constant pressure heat capacity decreased with pressure. The presence of vacancies also affected the thermal expansion coefficient and the high-temperature ductility of TiB, with V interstitial doping showing potential for improved ductility.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Chemistry, Physical
Zhicheng Huang, Kei Hayashi, Wataru Saito, Yuzuru Miyazaki
Summary: The addition of Ga as a dopant in Mg2Sn can change its conduction type from n-type to p-type, leading to an increase in the magnesium vacancy fraction and the introduction of hole carriers. This doping strategy results in a lower total thermal conductivity at a certain concentration, contributing to the improvement of thermoelectric material performance.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
M. Buryi, Z. Remes, V. Babin, M. Novotny, V. Vanecek, K. Aubrechtova Dragounova, J. Micova, L. Landova, R. Kucerkova, J. More-Chevalier, S. Chertopalov, P. Fitl, T. Kmjec
Summary: ZnO:Mo powders of nano- and microrods were fabricated by hydrothermal growth, while ZnO:Mo thin films were synthesized for comparison. Characterization using various techniques revealed luminescence modifications in the samples with different Mo content under annealing at elevated temperatures. The EPR spectra showed unique signals before and after treatments, indicating the presence of specific defects and luminescent properties.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Z. Benzarti, A. Khalfallah, Z. Bougrioua, M. Evaristo, A. Cavaleiro
Summary: This study investigates the impact of Mg doping concentration in GaN thin films on their physical and mechanical properties, specifically on their conductivity transition, luminescence, hardness, Young's modulus, and creep behavior. The results demonstrate that an increase in the Mg concentration leads to a conductivity transition from n-type to p-type, with the highest hole concentration and blue luminescence attained at a specific Mg concentration. Moreover, the hardness, Young's modulus, and the intensity of compressive stress increase with the Mg flow rate.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
