UScholar Works
 
Filters: Format: "application/pdf" Collection: "ir_uspace" Subject: "Pi-conjugated polymers"
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CreatorTitleDescriptionSubjectDate
1 Vardeny, Zeev ValentineCooperative emission in ∏-conjugated polymer thin filmsPicosecond dynamics of exciton emission and absorption have been studied in neat thin films of a variety of poly (phenylene vinylene) derivatives. We found that the stimulated emission band of 120 nm width and ~1 ns duration, which is observed at low exciton density n, collapses at n > 1017 cm-3 int...Pi-conjugated polymers; Poly (phenylene vinylene) derivatives; PPV derivatives; Cooperative emission1997-01
2 Vardeny, Zeev ValentineExciton dynamics in soluble poly(p-phenylene vinylene)We report studies of poly(2,5-dioctyloxy paraphenylene vinylene) thin films and solutions by a variety of transient, steady state, and nonlinear optical techniques. The energy states and optical absorption of the dominant even and odd parity excitons have been determined. Photogenerated singlet exci...Exciton dynamics; Poly(p-phenylene vinylene); PPV; Pi-conjugated polymers1997
3 Vardeny, Zeev ValentineFemtosecond dynamics of the nonlinear optical response in polydiethynylsilaneWe have measured the femtosecond dynamics of the nonlinear optical response xc3' in polydiethynylsilane ( C4H2SiBu2)x, a novel class of r-conjugated polymers incorporating Si, using degenerate four-wave mixing and photoinduced absorption techniques. In resonance conditions at 620 nm we found x (3) ...Polydiethynylsilane; Femtosecond dynamics; Nonlinear optical response; Pi-conjugated polymers1991
4 Vardeny, Zeev ValentineHigh-pressure effects on ultrafast-relaxation kinetics of excitons in polydiacetylene 4BCMUUltrafast-relaxation kinetics of the singlet excitons in polydiacetylene 4BCMU was measured at hydrostatic pressures up to 80 kbar, using the pump-probe photoinduced-absorption technique with 70-fs resolution at 2 eV and 5 ps in the spectral range 1.2-2.2 eV. The 100-fs decay component survives at...Ultrafast-relaxation; Polydiacetylene 4BCMU; Pi-conjugated polymers; Quasi-1D excitations1991-05
5 Vardeny, Zeev ValentineResonant Raman-scattering spectroscopy of polydiacetylene films at high pressureWe studied the electronic energies and phonon frequencies of polydiacetylene 4-BCMU thin films at high pressures up to 50 kbar using Raman scattering under preresonant and resonant conditions. Pressure-induced changes in the resonant Raman scattering (RRS) include (1) hardening of the most strongly...Resonant raman scattering spectroscopy; Polydiacetylene films; Pi-conjugated polymers1993-02
6 Vardeny, Zeev ValentineStudies of charged excitations in ∏-conjugated oligomers and polymers by optical modulationWe have studied photogenerated charged excitations in sexithiophene and a variety of p-conjugated polymers by photoinduced absorption (PA) and PA-detected magnetic resonance. We found distinct spin signatures for polarons and bipolarons, which enabled us to separate their contributions to the PA spe...Pi-conjugated oligomers; Pi-conjugated polymers; Charged excitations; Optical modulation; Spin signatures; Bipolarons; Photoexcitation1996-08
7 Vardeny, Zeev ValentineStudies of resonant and preresonant femtosecond degenerate four-wave mixing in unoriented conducting polymersDegenerate four-wave mixing with femtosecond time resolution is used to measure the magnitude and transient response of the third-order nonlinear optical susceptibility x(3) (ω;ω, -ω,ω) at 620 nm in nonoriented conducting polymers including polydiacetylene, polyacetylene, polyaniline, polydieth...Pi-conjugated polymers1991
8 Vardeny, Zeev ValentineSymmetric light emitting divices from poly(p-di ethynylene phenylene) (p-di phenylene vinylene) derivativesLight emitting devices were fabricated from 2,5-dialkoxy derivatives of poly(p-di ethynylene phenylene-p-di phenylene vinylene) (PDEPDPV) sandwiched between indium tin oxide (ITO) and Al. The current-voltage (Iel-V) curve, electroluminescence (EL) intensity-voltage (IEL-V) curve, and the EL spectra ...Poly(p-di ethynylene phenylene); PPV; Pi-conjugated polymers1995
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