Probe energies

Figure 15-6. (a) Phoioiuduccd absorption-detected magnetic resonance (ADMR) spectrum of MEH-PPV. HF and FF represents tire half field and full field powder pattern for the triplet (S=l) resonance, respectively, (b) ADMR spectrum ol MEH-PPV/CW, composite film. Both spectra were measured at probe energy 1.35 eV, T=4 K and 3 GHz resonant microwave frequency (reproduced by permission of the American Physical Society from Ref. 1191). 

Probe energy Beam diameter Beam current Analysis time Scattering angle Energy analyser... 

Diffuse reflectance infrared Fourier transform spectroscopy deuterium triglycine sulphate energy compensated atom probe energy dispersive analysis energy-loss near edge structure electron probe X-ray microanalysis elastic recoil detection analysis (see also FreS) electron spectroscopy for chemical analysis extended energy-loss fine structure field emission gun focused ion beam field ion microscope... 

Transient spectra were constructed by recording transients at desired wavelengths, all of which were normalized by the probe energy, and having the computer assemble spectra by connected points on each transient at a common delay time following the photolysis pulse. Kinetic information was obtained by monitoring transients at the desired wavelengths as a function of reactant gas pressure and/or cell temperature. Unless otherwise stated all experiments were carried out at 21 1° C. 

Figure 4b shows the measured transient difference absorption spectrum as a function of the x-ray probe energy E, recorded 50 ps after laser excitation (data points with error bars) for a sample containing 80 mmol/1 solution of [Ru"(bpy)3]2+ in H2O. This transient contains all the electronic changes from the reactant state absorption spectrum, R E), to the product state absorption spectrum, P(E,t), at the time t after photoexcitation. WithXO being the fraction of excited state species at time t, the transient absorption spectrum T(E,t) is given by... 

Energy accumulation = energy in heat transfer from jacket + energy in by calibration probe - energy lost by ambient heat transfer... 

Decker EL, Garoff S. (1996). Using vibrational noise to probe energy barriers producing contact angle hysteresis.Langmuir 12 2100-2110. 

More recent measurements vary the energy of the pump and probe independently (Fauchet et al. 1986). Some data are shown in Fig. 8.9 for a 2.0 eV pump and different probe energies. The transient response of the induced absorption is almost constant when the probe energy is above 2 eV as found by Vardeny and Tauc, but there is a fast decay of the absorption at lower probe energies. The decay is interpreted in terms of the bleaching of the absorption transitions which occurs when a carrier occupies a conduction band state and so inhibits the excitation of electrons from the valence band. The transient absorption is the... 

The transient induced absorption is different in doped or compensated a-Si H. The compensated material has fewer deep defects to cause rapid recombination so that the time dependence arises only from thermalization. The absorption transients are shown in Fig. 8.10 for a pump and probe energy of 2 eV (Thomsen et al. 1986). In contrast to the almost constant absorption of the undoped material (Fig. 8.8), there is now a rapid change from absorption to induced bleaching after... 

ST/T spectra for excitation intensity of 0.3 rnJ/cm and different pump-probe delays (t )) are shown in Figure 8-5. Positive AF for probe energies higher than... 

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