We have measured the wavelength dependence (340-215 nm) of one-photon photoemission from the ground electronic state of solvated electrons in bulk water, methanol, and ethanol. In every case, the vertical electron binding energy (VBE) gradually increased with photon energy, indicating that the photoelectron kinetic energy diminishes as a result of electron-vibration inelastic scattering prior to emission from the liquid surface. In contrast, the VBE of the Rydberg electron in DABCO (1,4-diazabicyclo[2,2,2]octane), which has a surface-excess density, revealed no clear wavelength dependence. These results suggest that the solvated electrons are created predominantly in the bulk and that VBEs measured using UV photoemission spectroscopy of liquids generally require energy corrections to account for inelastic scattering effects. From the wavelength dependence, we have re-estimated the VBEs of solvated electrons in bulk water, methanol, and ethanol to be 3.3, 3.1, and 3.1 eV, respectively. Hydrated electrons were also identified by photoemission spectroscopy using 90 nm radiation.

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Ultrafast photoelectron imaging using a 90 nm vacuum-UV probe pulse is applied to the ring-opening reaction of 1,3-cyclohexadiene (CHD) in the gas phase, and formation of 1,3,5-hexatriene (HT) and CHD in their electronic ground states is observed in real time. The analysis of the transient photoelectron kinetic energy spectra reveals the branching ratio into HT and CHD as 3:7 upon 270 nm photoexcitation. The ratio is in reasonable agreement with the experimental values reported for the liquid phase and theoretical values for the gas phase, resolving the discrepancy.

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Our crystalline In–Ga–Zn oxide (IGZO) thin film has a c‐axis‐aligned crystal (CAAC) structure and maintains crystallinity even on an amorphous base layer. Although the crystal has c‐axis alignment, its a‐axis and b‐axis have random arrangement; moreover, a clear grain boundary is not observed. We fabricated a back‐channel‐etched thin‐film transistor (TFT) using the CAAC‐IGZO film. Using the CAAC‐IGZO film, more stable TFT characteristics, even with a short channel length, can be obtained, and the instability of the back channel, which is one of the biggest problems of IGZO TFTs, is solved. As a result, we improved the process of manufacturing back‐channel‐etched TFTs.

Trans-polyacetylene with a degenerate ground state has a nonlinear excitation of soliton after photoexcitation, due to the electron-phonon coupling. The excess energy of an excited electron-hole pair over a soliton pair creation induces a breather oscillation characterized by collective stretching vibration of the carbon-carbon bonds. A time-frequency analysis of pump probe signal shows that instantaneous frequencies of stretching modes are modulated for approximately 50 fs after excitation and the modulation period is 44+/-3 fs consistent with the theoretical expectation, clearly verifying the breather.

Photoelectron spectra of solvated electrons in bulk liquids were obtained at energy-resolution of 60 meV using a linear time-of-flight photoelectron spectrometer and a 100 kHz ultraviolet femtosecond laser. Solvated electrons in H 2 O, D 2 O, methanol, and ethanol were generated by 226 nm excitation of the charge-transfer-to-solvent bands of Iin 0.1 M NaI solutions, and the photoelectron spectra were measured using 260 nm pulses with a time delay of 2 ns. The electron binding energies and band shapes are discussed.

Real-time impulsive resonant Raman scattering induced by a 4-fs ultrashort laser pulse was spectrally resolved with a multichannel lock-in amplifier. An optical and vibrational two-dimensional spectrum was introduced to separate the effects of electronic and vibrational broadening in the power spectrum of the vibrations. Spectrally resolved real-time oscillations can identify the wave packet motion associated with the stretching vibrational mode of the carbon-carbon double and triple bonds of the polymer polydiacetylene. Calculated nonlinear polarizations which take into account the ground-state wave packets reproduced the observed dynamics fairly well. It is confirmed that the ground-state vibrations play a significant role in the dynamics of the wave packet even far below the absorption edge, as well as the excited-state vibrations.