Packing-Shape Effects of Optical Properties in Amplified Spontaneous Emission through Dynamics of Orbit-Orbit Polarization Interaction in Hybrid Perovskite Quantum Dots Based on Self-Assembly.

This paper reports packing-shape effects of amplified spontaneous emission (ASE) through orbital polarization dynamics between light-emitting excitons by stacking perovskite (MAPbBr) quantum dots (QDs sized between 10 nm and 14 nm) into rod-like and diamond-like aggregates. The rod-like packing shows a prolonged photoluminescence (PL) lifetime (184 ns) with 3 nm red-shifted peak (525 nm) as compared to the diamond-like packing (PL peak, 522 nm; lifetime, 19 ns). This indicates that the rod-like packing forms a stronger interaction between QDs with reduced surface-charged defects, leading to surface-to-inside property-tuning capability with an ASE.

Organic Lead Halide Nanocrystals Providing an Ultra-Wide Color Gamut with Almost-Unity Photoluminescence Quantum Yield.

The most attractive aspect of perovskite nanocrystals (NCs) for optoelectronic applications is their widely tunable emission wavelength, but it has been quite challenging to tune it without sacrificing the photoluminescence quantum yield (PLQY). In this work, we report a facile ligand-optimized ion-exchange (LOIE) method to convert room-temperature spray-synthesized, perovskite parent NCs that emit a saturated green color to NCs capable of emitting colors across the entire visible spectrum. These NCs exhibited exceptionally stable and high PLQYs, particularly for the pure blue (96%) and red (93%) primary colors that are indispensable for display applications.

Perovskite Quantum Dots with Near Unity Solution and Neat-Film Photoluminescent Quantum Yield by Novel Spray Synthesis.

In this study, a novel perovskite quantum dot (QD) spray-synthesis method is developed by combining traditional perovskite QD synthesis with the technique of spray pyrolysis. By utilizing this new technique, the synthesis of cubic-shaped perovskite QDs with a homogeneous size of 14 nm is demonstrated, which shows an unprecedented stable absolute photoluminescence quantum yield ≈100% in the solution and even in the solid-state neat film. The highly emissive thin films are integrated with light emission devices (LEDs) and organic light emission displays (OLEDs).

New antimalarial norterpene cyclic peroxides from Xisha Islands sponge Diacarnus megaspinorhabdosa.

Four new norterpene cyclic peroxides (1-4), together with three known norterpene cyclic peroxides were isolated from the Xisha Islands Sponge Diacarnus megaspinorhabdosa. Their structures were elucidated on the basis of spectroscopic analyses and comparison with the related model compounds. The compounds (1-7) were evaluated for the inhibitory activity against the malaria parasite Plasmodium falciparum, all of them showed significant antimalarial activity with IC50 values in the range of 1.