摘要：Tin monosulfide(Sn S), which is composed of earth-abundant elements, holds promise as useful high-performance solar absorber and thermoelectric material. In addition to the ground-state Pnma phase, a series of metastable phases in different crystalline structures have been reported experimentally or theoretically, yet the phase stability diagrams remain elusive. In this article, we provide a comprehensive materials design study of new phases of Sn S using first-principles global optimization structure search calculations. We find that the two-dimensional layered phases are generally more energetically favored than the three-dimensional connected phases. In addition, we discover several new phases with comparable energetics. Four lower-energy phases show clear phonon stabilities evidenced by an absence of imaginary modes. The electronic band structures, carrier transport properties, and absorption spectra of the newly discovered phases are investigated and discussed toward potential applications for solar cells and thermoelectric devices.

摘要：Recent experiments report the rotation of FA(FA=HC[NH2]2+)cations significantly influence the excited-state lifetime of ***,the underlying mechanism remains *** ab initio nonadiabatic(NA)molecular dynamics combined with time-domain density functional simulations,we have demonstrated that reorientation of partial FA cations significantly inhibits nonradiative electron-hole recombination with respect to the pristine FAPbI3 due to the decreased NA coupling by localizing electron and hole in different positions and the suppressed atomic *** nuclear motions simultaneously increase the decoherence time,which is overcome by the reduced NA coupling,extending electron-hole recombination time scales to several nanoseconds and being about 3.9 times longer than that in pristine FAPbI3,which occurs within sub-nanosecond and agrees with *** study established the mechanism for the experimentally reported prolonged excited-state lifetime,providing a rational strategy for design of high performance of perovskite solar cells and optoelectronic devices.

摘要：Three "double-cable" conjugated polymers with thienopyrroledione-based backbone and perylene bisimide as side units were designed as electron acceptor for polymer-polymer solar cells. The polymers show broad absorption spectra and low-lying frontier energy levels due to both aromatic backbone and side units. The new double-cable polymers can be used as electron acceptor to combine with several electron donors, in which power conversion efficiencies above 3% could be achieved.

摘要：Rechargeable Li-O2 batteries have attracted considerable interests because of their exceptional energy density. However, the short lifetime still remained as one of the bottle-neck obstacles for the practical application of rechargeable Li-O2 batteries. The development of efficient cathode catalyst is highly desirable to reduce the energy barrier of Li-O2 reaction and electrode failure. In this work, we report a facile strategy for the fabrication of a high-per- formance cathode catalyst for rechargeable Li-O2 batteries by the encapsulation of high content of active Fe nanorods into N-doped carbon nanotubes with high stability （denoted as Fe@NCNTs）. First-principles calculations reveal that the synergistic charge transfer and redistribution between the interface of Fe nanorods, the CNT walls and the active N dopants greatly facilitate the chemisorption and subsequent dissociation of O2 molecules into the epoxy intermediates on the carbon surface, which benefits the uniform growth of nanosized discharge products on CNT surface and thus boosts the reversibility of Li-O2 reactions. As a result, the cathode with Fe@NCNT catalyst exhibRs long cycling sta- bility with high capacities （1000 mA h g-1 for 160 cycles and 600 mA h g-t for 270 cycles）. Based on the total mass of Fe@NCNTs ＋ Li2O2, high gravimetric energy densities of 2120-2600 W h kg-~ can be achieved at the power densities of 50-795 W kg-1.