Identifying strategies for beneficial band engineering is crucial for the optimization of thermoelectric (TE) materials. In this study, we demonstrate the beneficial effects of ionic dopants on n-type Mg Sb . Using the band-resolved projected crystal orbital Hamilton population, the covalent characters of the bonding between Mg atoms at different sites are observed. By partially substituting the Mg at the octahedral sites with more ionic dopants, such as Ca and Yb, the conduction band minimum (CBM) of Mg Sb is altered to be more anisotropic with an enhanced band degeneracy of 7. The CBM density of states of doped Mg Sb with these dopants is significantly enlarged by band engineering. The improved Seebeck coefficients and power factors, together with the reduced lattice thermal conductivities, imply that the partial introduction of more ionic dopants in Mg Sb is a general solution for its n-type TE performance. © 2019 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/jcc.25822 | DOI Listing |
Adv Sci (Weinh)
January 2025
Department of Materials Science and Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, Republic of Korea.
Hole-transport layers (HTL) in perovskite solar cells (PSCs) with an n-i-p structure are commonly doped by bis(trifluoromethane)sulfonimide (TFSI) salts to enhance hole conduction. While lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) dopant is a widely used and effective dopant, it has significant limitations, including the need for additional solvents and additives, environmental sensitivity, unintended oxidation, and dopant migration, which can lead to lower stability of PSCs. A novel ionic liquid, 1-(2-methoxyethyl)-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (MMPyTFSI), is explored as an alternative dopant for 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamino)-9,9'-spirobifluorene (spiro-OMeTAD).
View Article and Find Full Text PDFBone defects resulting from trauma or diseases that lead to bone loss have created a growing need for innovative materials suitable for treating bone-related conditions. The purpose of this study is, therefore, to synthesize and analyse the synergistic effects of cerium (Ce) and cerium-silver (Ce-Ag) doping of borosilicate bioactive glass (BBG) on the bioactivity, antibacterial properties, and biocompatibility for potential applications in bone tissue engineering. This study utilized a sol-gel Stöber method to synthesize doped BBGs based on S49B4.
View Article and Find Full Text PDFMolecules
December 2024
College of Medicine and Public Health, Flinders University, Bedford Park, Adelaide, SA 5042, Australia.
Zinc oxide nanoparticles (ZnO NPs) are one of the most widely used nanoparticulate materials due to their antimicrobial properties. However, the current use of ZnO NPs is hindered by their potential cytotoxicity concerns, which are likely attributed to the generation of reactive oxygen species (ROS) and the dissolution of particles to ionic zinc. To reduce the cytotoxicity of ZnO NPs, transitional metals are introduced into ZnO lattices to modulate the ROS production and NP dissolution.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Advanced Research in Electrochemical Impedance Spectroscopy Laboratory, Indian Institute of Technology Roorkee, Roorkee 247667, India.
The introduction of heterovalent metal ion doping in the lead (Pb) halide perovskites presents a novel opportunity to manipulate the electronic and ionic properties by introducing dopant charges and increasing the carrier concentration in single crystals. While previous studies have reported on the use of bismuth (Bi) doping in methylammonium lead tribromide (MAPbBr) to adjust the optical properties, the comprehensive impact of Bi doping on the structural and electronic properties of MAPbBr single crystals remains unexplored. This research, therefore, delves into the anomalous behavior of the structural, optical, and electrical properties of pristine and doped MAPbBr single crystals through a combination of experimental and computational studies.
View Article and Find Full Text PDFSmall
December 2024
Dalian National Laboratory for Clean Energy, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China.
Formamidine lead iodide (FAPbI) quantum dots (QDs) have attracted great attention as a new generation of photovoltaic material due to their long carrier diffusion length, benign ambient stability, and light-harvesting ability. However, its large surface area with inherent thermodynamic instability and highly defective ionic termination are still major obstacles to fabricating high-performance devices. Herein, a metallic ion dopant is developed to post-treat FAPbI QDs immediately after their fabrication by using a metal-glutamate salt solution.
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