Showing papers on "Pentacene published in 1974"
TL;DR: In this paper, the absorption spectra of oriented and amorphous naphthacene and pentacene films have been measured at high pressure, and the Davydov splitting of the 0-0 band in oriented films increase with increasing pressure at the rate of 37 cm−1/kbar for NPHTHACENE and 70 cm− 1/karp for pentACene.
Abstract: The absorption spectra of oriented and amorphous naphthacene and pentacene film have been measured at high pressure. The Davydov splitting of 0–0 band in oriented films increase with increasing pressure at the rate of 37 cm−1/kbar for naphthacene and 70 cm−1/kbar for pentacene. The 0–2 vibronic bands of both oriented films show the large red shifts compared with the 0–1 vibronic band. For amorphous films the Davydov splitting is not observed at atmospheric pressure. The pressure induced spectral red shifts in the amorphous state are slightly larger than those in the crystalline-state.
29 citations
TL;DR: In this article, the absorption spectra of oriented and amorphous naphthacene and pentacene films were measured at room temperature and the electronic state and reactivity for both states were discussed.
Abstract: The absorption spectra of the oriented and amorphous naphthacene and pentacene films were measured at room temperature. The electronic state and the reactivity for both states were discussed.
19 citations
TL;DR: In this article, the energies of the zero levels of the lower excited states of naphthalene and biphenyl and the mono- and di-negative ions of anthracene, tetracene and pentacene were determined by a closer inspection of lower frequency regions of their optical spectra.
12 citations
TL;DR: In this paper, the steady state and pulsed current-voltage-electroluminescence intensity dependences have been measured for pentacene-doped anthracene crystals over the temperature range 300-200°K.
Abstract: The steady state and pulsed current-voltage-electroluminescence intensity dependences have been measured for pentacene-doped anthracene crystals over the temperature range 300–200°K. Prompt and delayed electroluminescence from both host and guest are produced. The overall electroluminescence efficiency with respect to input power is much less than for neat anthracene crystals, though efficiency is still high, ∼10% with respect to crystal current.
10 citations
TL;DR: In this paper, the influence of magnetic field on the fluorescence of pentacene-doped tetracene single crystals, at high exciting light intensities (I o ≳ 10 16 ph/cm 2 sec), indicates the existence of an annihilation process of inequivalent triplet excitons.
7 citations
TL;DR: In this article, it was shown that below the solubility limit for substitutional mixing of pentacene in anthracene crystal, the anthracenes emission closely follows that of pure anthracines and that of the pentacenes is a well resolved spectrum showing three site origins and mirror symmetry with the absorption spectrum.
6 citations
TL;DR: In this paper, the authors measured the recombination radiation spectrum and its transient behavior on a pentacene doped anthracene crystal and found that the spectrum was more sensitive to chemical or physical impurities than optically sensitized fluorescence spectrum.
Abstract: The recombination radiation spectrum and its transient behavior were measured on a pentacene doped anthracene crystal. The recombination radiation spectrum was more sensitive to chemical or physical impurities than optically sensitized fluorescence spectrum. The intensity of both anthracene and pentacene emission was approximately proportional to the current. Anthracene or pentacene emission was found to consist of three components differing by their decay times; component 1 (decay time <10−5s), components 2,3 (decay times in the millisecond region, τ2<τ3). The component 1 was due to singlet excitons generated directly by carrier recombination. The component 2, the decay time of which was 2–3 ms, was due to triplet exciton annihilation, for its decay time was not affected by a reverse bias voltage and was equal to one half of the observed phosphorescence lifetime. The component 3, which was removed by a reverse bias voltage, was due to detrapped-trapped carrier recombination. Pentacene chemical impurity w...
1 citations