Two A–π–D–π–A carbazole derivatives differing in N-hexyl and N-isooctyl substituents were developed. They exhibited a prominent solvatochromic effect and luminescence turn-on characteristics under mechanical force stimuli.

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We designed a tandem organic light-emitting device based on an organic photovoltaic-type charge generation connector (CGC) of fullerene carbon 60/copper(II) phthalocyanine. The CGC can absorb a portion of photons radiated from emission zone and form excitons which disassociated into free charges at PN junction interface without energy barrier, leading to low driving voltage and better charge balance. The efficiency increases remarkably with increasing current density, even beyond two folds compared with single unit device under higher current density, meaning slower roll-off. The whole process is a positive cycle, and actually enhances the utilization of internal radiation and the overall performance of tandem device.

In this work, two carbazole- and benzo[d]oxazole-based novel multifunctional materials with hybridized local and charge-transfer (HLCT) characteristic, namely OCI and OCT, which could act as deep-blue fluorophors and phosphorescent hosts,...

Chiral hybrid halide perovskites have attracted considerable attention in optoelectronics and spintronics owing to their unique optical, electric, and spin–orbit coupling (SOC) properties. In this article, with focus on the design scheme to increase the nonlinear optical (NLO) circular dichroism (CD) and spin selectivity effects by assembling chlorine-modified chiral R-/S-CLPEA [CLPEA = 1-(4-chlorophenyl)ethylamine] into bismuth-based perovskites, a pair of chiral hybrid perovskites (R-/S-CLPEA)4Bi2I10 were synthesized and characterized experimentally. A large NLO CD effect and strong spin-dependent charge transport were confirmed by the experimental measurements. The unique chirality-induced spin textures were illustrated in the SOC band structures from first-principles simulations. The combined theoretical and experimental results demonstrate that it is the synergic effect of large chirality of CLPEA and strong SOC effect of the Bi2I10 dimer that endows these perovskites with unique chiral spin textures, strong NLO CD effect, and remarkable spin-dependent charge transport properties, which are of importance for the functional design of chiral perovskites in nonlinear optics and spintronics.

Metal oxides have been attractive as high-capacity anode materials for lithium-ion batteries. However, oxide anodes encounter drastic volumetric changes during lithium ion storage through the conversion reaction and alloying/dealloying processes, leading to rapid capacity decay and poor cycling stability. Here, we report a free-standing SnO 2 @reduced graphene oxide (SnO 2 @rGO) composite anode, in which SnO 2 nanoparticles are tightly wrapped within wrinkled rGO sheets. The SnO 2 @rGO sheet is assembled in high porosity via an anti-solvent-assisted precipitation of dispersed SnO 2 nanoparticles and graphene oxide sheets in the distilled water, followed by the filtration and post-annealing processes. Significantly enhanced lithium storage performance has been obtained of the SnO 2 @rGO anode compared with the bare SnO 2 anode material. A high charge capacity above 700 mAh g −1 can be achieved with a satisfying 95.6% retention after 50 cycles at a current density of 500 mA g −1 , superior to reserved 126 mAh g −1 and a much lower 16.8% retention of the bare SnO 2 anode. XRD pattern and HRTEM images of the cycled SnO 2 @rGO anode material verify the expected oxidation of Sn to SnO 2 at the fully-charged state in the 50th cycle. In addition, FESEM and TEM images reveal the well-preserved free-standing structure after cycling, which accounts for high reversible capacity and excellent cycling stability of such a SnO 2 @rGO anode. This work provides a promising SnO 2-based anode for high-capacity lithium-ion batteries, together with an effective fabrication adoptable to prepare different free-standing composite materials for device applications.

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