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The symmetry adapted cluster (SAC) and SAC-configuration interaction (SAC-CI) theories are applied to the calculations of the ground and excited states of MnO-4. With the use of three different active spaces, we examine the convergence of the results. Electron correlations work to relax charge polarizations of the Mn–O bonds in the ground state. The experimental spectrum of MnO-4 is well reproduced by the present calculations. All of the observed peaks are assigned to the electronic allowed transitions to the 1T2 excited states. They are characterized as the excitations from the nonbonding orbitals of oxygen to the antibonding orbitals between the metal and oxygens. For reasonable descriptions of the ground and excited states of MnO-4, electron correlations should be considered with the use of large enough active space for expressing the relaxations of valence electrons. In this sense, all of the previous theoretical assignments of the spectra are unreliable, since they are not the results of calculations including sufficient amount of electron correlations. [ABSTRACT FROM AUTHOR]

Examines the ratio dependence of molecular-beam epitaxy grown gallium-aluminum-antimony material system. Description of X-ray diffraction; Discussion on growth mechanisms; Details of the Raman scattering measurement.

Reveals that the characteristics of Schottky gated field effect transistors fabricated utilizing poly(3-alkylthiophene) containing diphenyliodonium hexafluoroarsenate can be controlled by irradiating light on it. Results and discussion.

Studies the dependencies of photoluminescence in five membered heterocyclic conducting polymers on heteroatoms and temperature. Photoluminescence spectra of poly(3-hexylthiophene) at various temperatures; Temperature dependence of luminescence intensity of poly(3-alkylthiophene) with various alkyl chain lengths; Absorption spectra of poly(3-hexylthiopene) at various temperatures.

pn-Heterojunction organic photovoltaic devices (OPVs) using amorphous molecular materials with high hole drift mobilities of 10-2 cm2 V-1 s-1, tris[4-(2-thienyl)phenyl]amine and tris[4-(5-phenylthiophen-2-yl)phenyl]amine, as electron donors and fullerene as an electron acceptor were fabricated. In spite of the use of amorphous materials instead of crystalline materials, the devices exhibited high performance with fill factors of 0.62–0.71 and power conversion efficiencies of 1.5%–1.7% under air-mass 1.5 G illumination at an intensity of 100 mW cm-2. [ABSTRACT FROM AUTHOR]

For the purpose of exploring near-infrared emission, the photoluminescence (PL) and electro- luminescence (EL) of N,N′-bis(neopentyl)-3,4:9,10-perylenebis(dicarboximide) (BNPTCD): tris(8-quinolinolato)aluminum (Alq3) mixed films were investigated. It was found that BNPTCD:Alq3 mixed films exhibit PL in the near-infrared wavelength region and that organic light-emitting diodes using Alq3 highly doped with BNPTCD as an emitting layer exhibit near-infrared EL with a peak at 805 nm originating from BNPTCD aggregates. [ABSTRACT FROM AUTHOR]

Examines the spectral narrowing and emission energy shift in organic electroluminescent (EL) diode utilizing 8-hydroxyquinoline aluminum or aromatic diamine multilayer structure. Components of the organic EL diode; Mechanism of spectral narrowing and the emission energy; Results of the confined carriers in the multilayer system.

Examines the fabrication and characteristics of 8-hydroxyquinoline aluminum and aromatic diamine multiple quantum well (MQW). Growth of MQW by organic molecular beam deposition; Indication of a quantum size effect by the photoluminescence; Production of an electroluminescent diode.

We have realized a three-layered multicolor organic electroluminescent device utilizing poly (9,9-dihexylfluorene) and perylene derivatives as emission layers, with diamine derivatives as an electron blocking layer. Emission colors could be selected either blue or red by changing the polarity of the applied voltage. By driving with an ac biased electric field, both emission colors were observed and the intensity ratio of each emission color was modulated by the frequency of the applied ac field. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]