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Triboelectrification can occur between any two materials with different charge affinities. This phenomenon represents the fundamental physics of triboelectric nanogenerators (TENGs). Organic materials such as polymers have been widely used in TENGs because of their dielectric properties. Inorganic materials are, however, not widely studied despite the increasing attention paid to perovskite materials. In this paper, a new type of TENG has been fabricated based only on inorganic materials such as Mo6S3I6 and indium tin oxide (ITO). The output power density of the TENG operating in contact-separation mode reaches 18 W m−2. Mechanisms of the high output involve the unique semiconducting property of Mo6S3I6 and the unique chemical composition of ITO. The findings in this study indicate that inorganic materials can be used for fabricating high-output TENGs for energy harvesting.

The effect of disorder in high-T-c superconductors is investigated from the viewpoint of photoinduced quasipartick (QP) dynamics, obtained through time-resolved pump-probe spectroscopy. We perform the measurements on an optimally doped (OPD) Bi2+xSr2-xCaCu2O8+delta (Bi2212) with an out-of-plane disorder induced by Bi-Sr substitution (x), which is present in standard Bi2212 but is not usually controlled. Based on the systematic change of the disorder with controlled x, we identify the changes in the dynamics of QP relaxation and gap formation in superconducting (SC) and pseudogap (PG) states. The onset temperature T* of the PG response increases with an increase in x, which is more significant than the slight decrease in T-c. These properties are equivalently reflected in the destruction fluences of the SC and PG states. Bi-Sr substitution also accelerates relaxation times for SC and PG QPs, which can be due to the increased phonon scattering probability caused by the disorder. In contrast, the SC gap recovery observed in the strongly excited condition shows an identical fluence dependence for various x, implying that the disorder does not significantly contribute to coherent gap formation.

We investigate the quench and real-time formation of the Mott state and photoexcited carrier relaxation dynamics in the Mott insulator kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Cl(kappa-Cl) and the superconductor kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br(kappa -Br) using three-pulse femtosecond optical spectroscopy, where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene. In both salts, we find that transient reflectivity amplitude gradually recovers with time after strong near-infrared pulse quench, but its relaxation time is nearly constant throughout. This indicates that in K-Cl, the energy gap for charge excitations is filled rather than closed by photoinduced carriers of only similar to 0.5% per dimer. The Mott state is re-formed on a few-picosecond timescale with the disappearance of the in-gap photodoping-induced states near the Fermi energy. In kappa-Br, a behavior similar to that in kappa-Cl is observed and attributed to the disorder-induced phase-separated Mott insulating regions.

The effect of disorder in high-T-c superconductors is investigated from the viewpoint of photoinduced quasipartick (QP) dynamics, obtained through time-resolved pump-probe spectroscopy. We perform the measurements on an optimally doped (OPD) Bi2+xSr2-xCaCu2O8+delta (Bi2212) with an out-of-plane disorder induced by Bi-Sr substitution (x), which is present in standard Bi2212 but is not usually controlled. Based on the systematic change of the disorder with controlled x, we identify the changes in the dynamics of QP relaxation and gap formation in superconducting (SC) and pseudogap (PG) states. The onset temperature T* of the PG response increases with an increase in x, which is more significant than the slight decrease in T-c. These properties are equivalently reflected in the destruction fluences of the SC and PG states. Bi-Sr substitution also accelerates relaxation times for SC and PG QPs, which can be due to the increased phonon scattering probability caused by the disorder. In contrast, the SC gap recovery observed in the strongly excited condition shows an identical fluence dependence for various x, implying that the disorder does not significantly contribute to coherent gap formation.