Vibrationally resolved photoelectron spectroscopy and Schwinger calculations are used to characterize a new resonance phenomenon in the 5sigma(u)-->ksigma(u) photoionization of CS2. This resonant channel is symmetry forbidden, yet is observable because it is activated by the antisymmetric stretching vibration. In addition, we show that a Franck-Condon breakdown occurs even though the energy dependence of the cross section is insensitive to geometry changes, which is unprecedented in photoionization.
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http://dx.doi.org/10.1103/PhysRevLett.92.143002 | DOI Listing |
Nat Commun
October 2024
Department of Electronic and Electrical Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen, 518055, China.
Electrons and holes, fundamental charge carriers in semiconductors, dominate optical transitions and detection processes. Twisted van der Waals (vdW) heterostructures offer an effective approach to manipulate radiation, separation, and collection processes of electron-hole pairs by creating an atomically sharp interface. Here, we demonstrate that twisted interfaces in vdW layered black phosphorus (BP), an infrared semiconductor with highly anisotropic crystalline structure and properties, can significantly alter both recombination and separation processes of electron-hole pairs.
View Article and Find Full Text PDFPhys Chem Chem Phys
October 2024
Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
Iron is the most abundant transition metal in the interstellar medium (ISM), and is thought to be involved in a variety of astrochemical processes. Here, we present the infrared multiple photon dissociation (IRMPD) spectra of ArFeH and their deuterated isotopologues in the region of 2240-14 000 cm. The Fe-H overtone stretching mode in ArFeH and ArFeH is observed at 3636 ± 28 cm and 3659 ± 13 cm, respectively.
View Article and Find Full Text PDFJ Chem Phys
April 2024
Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, United Kingdom.
Owing to ring strain, cyclic ketones exhibit complex excited state dynamics with multiple competing photochemical channels active on the ultrafast timescale. While the excited state dynamics of cyclobutanone after π* ← n excitation into the lowest-energy excited singlet (S1) state has been extensively studied, the dynamics following 3s ← n excitation into the higher-lying singlet Rydberg (S2) state are less well understood. Herein, we employ fully quantum multiconfigurational time-dependent Hartree (MCTDH) simulations using a model Hamiltonian as well as "on-the-fly" trajectory-based surface-hopping dynamics (TSHD) simulations to study the relaxation dynamics of cyclobutanone following 3s ← n excitation and to predict the ultrafast electron diffraction scattering signature of these relaxation dynamics.
View Article and Find Full Text PDFAdv Sci (Weinh)
April 2024
Department of Engineering Science, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan.
Molecular vibrations are often factors that deactivate luminescence. However, if there are molecular motion elements that enhance luminescence, it may be possible to utilize molecular movement as a design guideline to enhance luminescence. Here, the authors report a large contribution of symmetry-breaking molecular motion that enhances red persistent room-temperature phosphorescence (RTP) in donor-π-donor conjugated chromophores.
View Article and Find Full Text PDFJ Phys Condens Matter
December 2023
ISIS Facility, STFC, Didcot, Oxfordshire OX11 0QX, United Kingdom.
Published magnetic data for LaCoOare successfully analyzed with coexistingand low-spin (LS) cobalt states. Energy levels of the two states are derived in analytic forms. To this end, fictitious orbital angular momentumof magnitude one defines the Γ() state.
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