Showing papers on "Photoexcitation published in 1969"
TL;DR: The mechanism of charge transfer between energy states of electrons in electrodes and redox systems was studied in this paper, where it was shown that not only conduction and valence band but also surface states are involved in the charge transfer at the interface.
Abstract: The mechanism of the charge transfer between energy states of electrons in electrodes and redox systems was studied. Measurements of the photoexcitation of electrons in have shown that not only the conduction and valence band but also surface states are involved in the charge transfer at the interface. Electroluminescence is observed if minority carriers are injected into the electrode. The corresponding recombination process is compared with that of the photoluminescence. Quenching effects are discussed.
84 citations
TL;DR: In this article, a method was developed and employed for an LCAO-MO semiquantitative determination of valence bands, which seems generally advantageous for complex solids with important covalent bonding effects.
80 citations
TL;DR: In this article, the high-resolution singlet-triplet absorption spectrum of crystalline naphthalene at 4.2°K was obtained by a photoexcitation technique and analyzed.
Abstract: The high‐resolution singlet–triplet absorption spectrum of crystalline naphthalene at 4.2°K was obtained by a photoexcitation technique. The spectrum is presented and analyzed. The spectrum primarily consists of strong Ag modes that exhibit factor‐group splitting and that are primarily polarized normal to the molecular plane. The total factor‐group splitting of − 32 cm−1 is in agreement with that measured directly in absorption. The crystal polarization properties of the spectrum serve to identify the high‐energy components of the Davydov pairs as belonging to the (+) or Au factor‐group component. The spectrum clearly reveals the presence of certain antisymmetric modes, which appear with an intensity that is about two orders of magnitude less than that of the 0, 0.
53 citations
TL;DR: Simultaneous photoexcitation and photoionization of He near threshold at 186 A, measuring probability as mentioned in this paper, where the probability of photo-excitation was defined as the probability that He was photoexcited or photoionized.
Abstract: Simultaneous photoexcitation and photoionization of He near threshold at 186 A, measuring probability
48 citations
TL;DR: In this paper, a discussion of laboratory measurements of ionization, fluorescence, and photodetachment is devoted to molecules of aeronomic interest but excludes atoms The section on photodeteachment includes only work which has appeared since 1964 Current data are presented on photoionization cross sections, dissociative ionization crosssections, cross sections for the excitation of particular states of ions, relative vibrational excitation probabilities, photodelectric cross sections.
Abstract: This review is devoted to a discussion of laboratory measurements of ionization, fluorescence, and photodetachment The review is limited to molecules of aeronomic interest but excludes atoms The section on photodetachment includes only work which has appeared since 1964 Current data are presented on photoionization cross sections, dissociative ionization cross sections, cross sections for the excitation of particular states of ions, relative vibrational excitation probabilities, photodetachment cross sections, angular distributions of electrons from photoionization, and dissociative excitation of neutral molecules Some suggestions are made for further work
39 citations
TL;DR: In this paper, the spectral response of the photocurrent yield in the entire photon-energy range studied (0.95 − 3.4 eV) originates from optical excitation of electrons from a single discrete set of traps which is continuously filled by electron injection from the active metal contact.
Abstract: Dark- and photo-current measurements are used to study trap characteristics and optical de-trapping processes in anthracene samples provided with alkali and alkaline-earth metal contacts. The spectral response of the photocurrent yield in the entire photon-energy range studied (0.95–3.4 eV) originates from optical excitation of electrons from a single discrete set of traps which is continuously filled by electron injection from the active metal contact. The traps are 0.95 eV deep and are present with a density of about 1013 cm−3. De-trapping appears to occur by direct photoexcitation into the conduction band at long wavelengths and by interaction of occupied traps with triplet and singlet excitons at shorter wavelengths. The spectral yield curve exhibits considerable structure which can be advantageously used to study the various electronic-vibronic states in anthracene.
30 citations
14 citations
1 citations
Book•
01 Jan 1969
TL;DR: In this paper, the group dynamical prescriptions for constructing conserved currents of baryons of fixed internal quantum numbers are extended as to apply to the whole SU(3) octet of weak and electromagnetic curents.
Abstract: The group dynamical prescriptions for constructing conserved currents of baryons of fixed internal quantum numbers are extended as to apply to the whole SU(3) octet of weak and electromagnetic curents.
TL;DR: In this paper, a beam of coherent monochromatic off-resonance photons is passed through a gas, and the competing processes of excitation and de-excitation lead to an equilibrium concentration of excited molecules, which is proportional to the beam intensity.
Abstract: Even in the frame of first-order perturbation theory a molecule can be excited by off-resonance photons if it is subjected to a line-broadening mechanism. The case of collision-broadening is considered here. When a beam of coherent monochromatic off-resonance photons is passed through a gas, the competing processes of excitation and de-excitation lead to an equilibrium concentration of excited molecules, which is proportional to the beam intensity. This concentration is computed through the successive use of a classical and of a semi-quantum-mechanical treatment. Ionization is considered as a special case of excitation. The probability of ionization deduced from this theory in the case of medium pressures, is larger than that of multiphoton ionization.
TL;DR: In this paper, the effect of uniaxial stress on these lines was reported, and the effect on the lines was investigated at the liquid helium temperature of the acceptors in AlSb.