An experimental and theoretical study is reported to investigate the influence of bromine doping on CHNHPb(I Br ) perovskite for Br compositions ranging from = 0 to = 0.1, in which the material remains in the tetragonal phase. The experimental band gap is deduced from UV-vis absorption spectroscopy and displays a linear behavior as a function of bromine concentration. Density functional theory calculations are performed for five different series of randomly doped structures in order to simulate the disorder in bromine doping sites. The computations predict a linear variation of the lattice parameters, supercell volume, density, band gap, and formation energy in the considered doping range. The calculated evolution of the band gap as the function of Br doping is in excellent agreement with the experimental data, provided that different Br doping configurations are included in the simulations. The analysis of the structural and electronic properties shows a correlation between the increase of the band gap and the increased distortion of the Pb(I Br ) octahedrons. Additionally, the simulations suggest that in CHNHPb(I Br ) bromine doping is likely to occur at both the equatorial and apical positions of the octahedrons.
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http://dx.doi.org/10.1021/acsomega.0c04406 | DOI Listing |
J Mol Model
January 2025
Nanjing Hydraulic Research Institute, Shanghai, China.
Context: This study systematically investigated the effects of single S-atom vacancy defects and composite defects (vacancy combined with doping) on the properties of MoS using density functional theory. The results revealed that N-doped S-vacancy MoS has the smallest composite defect formation energy, indicating its highest stability. Doping maintained the direct band gap characteristic, with shifts in the valence band top.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Sichuan University, School of Chemical Engineering, No.24 South Section 1, Yihuan Road, 610065, Chengdu, CHINA.
Covalent organic frameworks (COFs) are often employed in oxygen reduction reactions (ORR) for hydrogen peroxide production due to their tunable structures and compositions. However, COF electrocatalysts require precise structural engineering, such as heteroatoms or metal site doping, to modulate the reaction pathway during the ORR process. In this work, we designed a tetraphenyl-p-phenylenediamine based COF electrocatalyst, namely TPDA-BDA, which exhibited excellent two-electron (2e) ORR performance with high H2O2 selectivity of 89.
View Article and Find Full Text PDFACS Phys Chem Au
January 2025
Modeling and Molecular Simulation Group, São Paulo State University (UNESP), School of Sciences, Bauru 17033-360, Brazil.
This study introduces the penta-structured semiconductor p-CGeP through density functional theory simulations, which possesses an indirect band gap transition of 3.20 eV. Mechanical analysis confirms the mechanical stability of p-CGeP, satisfying Born-Huang criteria.
View Article and Find Full Text PDFNbO(OH) has emerged as a highly attractive photocatalyst based on its chemical stability, energetic band positions, and large active lattice sites. Compared to other various photocatalytic semiconductors, it can be synthesized easily. This study presents a systematic analysis of pristine and doped NbO(OH) based on recent developments in related research.
View Article and Find Full Text PDFNanoscale Adv
January 2025
Institute of Theoretical and Applied Research, Duy Tan University Ha Noi 100000 Vietnam
In this work, we investigate the electronic and magnetic properties of the InSe monolayer enriched by doping with IVA-group (Si and Ge) and VA-group (P and As) atoms. Both In and Se sublattices are considered as doping sites to realize n- and p-type doping (X@InSe and X@InSe systems, X = Si, Ge, P, and As), respectively. The pristine InSe monolayer is an indirect gap semiconductor with a band gap of 1.
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