Although many studies have been carried out on the doping of transition metal dichalcogenides (TMDCs), introducing controllable amounts of dopants into a TMD lattice is still insufficient. Here we demonstrate doping controlled TMDC growth by the replacement of selenium with phosphorus during the synthesis of the monolayer WSe2. The phosphorus doping density was precisely controlled by fine adjustment of the amount of P2O5 dopant powder along the pre-annealing time. Raman spectroscopy, photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and high-angle annular bright field scanning tunneling electron microscopy (HAADF STEM) provide evidence that P doping occurs within the WSe2 crystal with P occupying the substitutional Se sites. With regard to its electrical characteristics, the hole majority current of P-doped WSe2 is 100-times higher than that of the intrinsic WSe2. The measured doping concentration ranged from ∼8.16 × 1010 to ∼1.20 × 1012 depending on the amount of P2O5 dopant powder by pre-annealing.
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http://dx.doi.org/10.1039/c8nr03427c | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Ritsumeikan University: Ritsumeikan Daigaku, Applied Chemistry, B805 Biolink, 1-1-1 Nojihigashi, 525-8577, Kusatsu, JAPAN.
Inorganic photochromic materials offer several advantages over organic compounds, including relatively inexpensive and higher thermal stability. However, tuning their color with the same component has remained a significant challenge. In this study, we demonstrate that the photochromic color of Cu-doped ZnS nanocrystals (NCs), which is initially pale yellow before light irradiation, can be tuned from gray to brown by adjusting the surface stoichiometry of Zn and S, which is controlled through the use of thiol and non-thiol ligands.
View Article and Find Full Text PDFLasers Med Sci
January 2025
University of Zurich, Zurich, Switzerland.
The aim of this study was to compare the effectiveness of different types of low level laser treatment (LLLT) in reducing pain levels, changing oxygen saturation and bite force in patients with myofacial pain syndrome (MPS). 45 patients were randomly assigned to three groups: Group 1 (GRR laser, n = 15) received LLLT with Gallium-Aluminium-Arsenide (GaAlAs) diode laser with a wavelength of 904 nm and red laser with a wavelength of 650 nm over masseter muscle region. Group 2 (Nd: YAG laser, n = 15) were treated with Neodymium-doped Yttrium Aluminium Garnet laser with a wavelength of 1064 nm and the same protocol with Nd: YAG laser was performed in the Group 3 (placebo, n = 15) using sham device.
View Article and Find Full Text PDFAdv Mater
January 2025
Hunan Key Laboratory of Two-Dimensional Materials, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, China.
The exchange bias (EB) effect is a fundamental magnetic phenomenon, in which the exchange bias field/coercive field ratio (|H/H|) can improve the stability of spintronic devices. Two-dimensional (2D) magnetic heterostructures have the potential to construct low-power and high-density spintronic devices, while their typically air unstable and |H/H| lesser, limiting the possibility of applications. Here, 2D CrTe nanosheets have been systematically synthesized with an in situ formed ≈2 nm-thick Te doped CrO layer (Te-CrO) on the upper surface by chemical vapor deposition (CVD) method.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Department of Environmental Science and Engineering, Fuzhou University, Minhou, Fujian 350108, China; State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Minhou, Fujian 350108, China. Electronic address:
Covalent triazine frameworks (CTFs) are emerging as promising platform for photocatalysis, yet their highly symmetric structure leads to significant charge recombination. Herein, we employed a facile non-metallic boron (B) modification with precisely controlled doping site to introduce asymmetric local electron distribution in CTFs, achieving a 15-fold activity enhancement for CO-to-CH conversion. Calculations including frontier orbitals, dipole moments and molecular electrostatic potentials firmly demonstrated the formation of localized polarized electron regions in CTF-1 via B doping.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Physics, Khalifa University of Science and Technology, 127788, Abu Dhabi, United Arab Emirates.
In this study, biopolymer composites based on chitosan (CS) with enhanced optical properties were functionalized using Manganese metal complexes and black tea solution dyes. The results indicate that CS with Mn-complexes can produce polymer hybrids with high absorption, high refractive index and controlled optical band gaps, with a significant reduction from 6.24 eV to 1.
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