98%
921
2 minutes
20
When the polarization direction of the laser beam Ê lies on the graphene plane, the absorption spectrum A(ω)is isotropic and includes one sharp peak and some shoulders. As for Ê along the stacking direction, A(ω) is much weaker, and shows only one broadened peak. Because of the dipole matrix element M(cv), the optical excitations do not fully reflect the features of electronic structures [or the joint density of states (JDOS)]. M(cv) plays an important role in the relationship between A(ω) and JDOS. It is strongly dependent on Ê, showing an anisotropic property.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/OL.36.003136 | DOI Listing |
Anal Chem
September 2025
Interdisciplinary Laboratories for Advanced Materials Physics (i-LAMP) & Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, via della Garzetta 48, 25133 Brescia, Italy.
Optical recognition and identification of nanoplastics such as polystyrene nanobeads (PSbs), a widely used polymer and an actual source of environmental pollution, is a challenging task relying on knowledge of the PSbs' refractive index (RI) and its relation to the PSbs' morphology. This is, however, lacking for PSbs' sizes lower than 1 μm. Here, we bridge this gap by measuring UV-vis spectra of PSbs deposited on a sapphire substrate via spin coating and by connecting the experimental data to the RI, PSbs' morphology, and optical transitions through a new optical model based on the Mie theory.
View Article and Find Full Text PDFJ Phys Chem A
August 2025
Department of Chemistry, Bhatter College, Dantan, P.O. Dantan, Paschim Medinipur, Dantan 721426, India.
Tetracyanoquinodimethane (TCNQ) and related compounds are thoroughly investigated as potential innovative organic semiconductors and singlet fission (SF) materials. The TDDFT method with the PBE0/Def2-TZVP level is used to determine the geometrical structures, atomic dipole corrected Hirshfeld (ADCH) charge, population, dipole moment (μ), band gaps, different density of states (DOSs), excitation energies, hole-(λ) and electron-(λ) reorganization energies, SF properties, absorption-emission spectra, transition density matrix (TDM), electron localization function (ELF) of these molecules, and open circuit voltage (), fill factor (FF), and power conversion efficiency (PCE) of possible optoelectronic devices. At the CAM-B3LYP/6-311G** level, we examine the ground and excited state characteristics of 44 modeled TCNQ-related molecules.
View Article and Find Full Text PDFChemphyschem
August 2025
Departamento de Ciencias Exactas y Tecnología, Centro Universitario de los Lagos, Universidad de Guadalajara, Enrique Díaz de León 1144, Lagos de Moreno, 47460, Jalisco, México.
This study explores the molecular structures and properties of quinoxaline-based donor materials complexed with highly efficient electron-acceptor molecules in organic solar cells. Employing density functional theory calculations, the interaction between PBQX (X = 5-F, 6-F, 5-Cl, 5-Br, 6-Cl, 6-Br) electron donors and two well-known electron acceptors (Y6 and BTP-4Br) is systematically analyzed. Variations in the halogen atoms of donor compounds are examined to assess their impact on the electronic structure of donor-acceptor complexes.
View Article and Find Full Text PDFJ Chem Theory Comput
September 2025
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
Molecular polaritons are hybrid light-matter states that enable the exploration of potential cavity-modified chemistry. The development of dynamical, first-principles approaches for simulating molecular polaritons is important for understanding their origins and properties. Herein, we present a hierarchy of first-principles methods to simulate the real-time dynamics of molecular polaritons in the strong coupling regime.
View Article and Find Full Text PDFImaging Neurosci (Camb)
April 2025
Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom.
Optically-pumped magnetometers (OPMs) are compact and lightweight sensors that can measure magnetic fields generated by current flow in neuronal assemblies in the brain. Such sensors enable construction of magnetoencephalography (MEG) instrumentation, with significant advantages over conventional MEG devices, including adaptability to head size, enhanced movement tolerance, lower complexity, and improved data quality. However, realising the potential of OPMs depends on our ability to perform system calibration-which means finding sensor locations, orientations, and the relationship between the sensor output and magnetic field (termed sensor gain).
View Article and Find Full Text PDF