Yasushi Hirose

We considered the trans → cis photoisomerization dynamics of the S2-excited azobenzene derivatives in terms of the potential energy gap between the n-π* (S1) and the π-π* (S2) state. The photoisomerization dynamics of trans-4-aminoazobenzene (trans-4-AAB) which has an energy gap (3000−4000 cm-1) rather smaller than that of trans-azobenzene (∼10000 cm-1) due to an amino-substitution was investigated using UV−vis transient absorption spectroscopy. The recorded transient absorption spectra of the π

Electron mass anisotropy in the Nb-doped anatase ${\text{TiO}}_{2}$ (TNO) was determined by polarized infrared spectroscopy measurements for (012)-oriented TNO epitaxial films. The electron mass along the $c$ axis, ${m}_{⟨001⟩}^{\ensuremath{\ast}}$, derived by Drude analyses, was found to be $0.5--3.3\text{ }{m}_{0}$, which was 3--6 times larger than that along the $a$ axis, ${m}_{⟨100⟩}^{\ensuremath{\ast}}$, $0.2--0.6\text{ }{m}_{0}$. This large anisotropy was attributed to not only the anisotr

The ultrafast relaxation dynamics of a widely used viscosity probe molecule, auramine O (AuO), was investigated in water and a water/aerosol−OT (AOT)/n−heptane reversed micelle. We discussed the contribution of specific interactions between AuO and the local environment to the relaxation dynamics. The transient absorption spectra of AuO showed that the nonradiative relaxation process of the photoexcited AuO in the AOT-reversed micelle was approximately 1 order slower than that in bulk water and

Transparent conductive oxides (TCOs) are key materials for highly efficient optoelectronic devices such as light-emitting diodes (LEDs) and photovoltaic cells. While high-performance TCOs have been developed for use in the visible light spectrum, few materials are identified as TCOs feasible for deep ultraviolet (DUV) devices, especially at wavelengths shorter than 280 nm (UV-C region). Herein, we demonstrate that an alloy of rutile SnO2 and isostructural GeO2, rutile Sn1–xGexO2 (SGO), is a prom