Optimizing the stability and improving photoluminescence quantum yields (PLQYs) of all-inorganic halide perovskite nanocrystals has become an urgent and challenging task to promote its application in the field of optoelectronic devices. Lead halide perovskite CsPbX3 (X = Br, I, Cl) often suffers from many serious issues, mainly from changes in the environment (thermal, chemical, light excitation). To better solve these thorny problems, two different core–shell heterostructures were proposed to protect CsPbX3, and the changes of photoluminescence (PL) characteristics under different external conditions were studied. Here, a more stable CdS with adjacent absorption bands was selected as the shell protection layer, and the CsPbBr3@CdS core–shell quantum dots (QDs) were prepared by epitaxial growth strategy. To confirm the comprehensive stability of the CsPbBr3@CdS QDs, the integrated CsPbBr3@Cs4PbBr6 core–shell nanocrystals (NCs) were taken as a reference. Interestingly, the results show that individual CsPbBr3@CdS QDs not only show excellent comprehensive (thermal, chemical, light excitation) stability compared to integrated CsPbBr3@Cs4PbBr6 but also offer improved PLQY of naked CsPbBr3 from 81 to 86% in the presence of a CdS shell. Our results will promote the further commercial development of inorganic perovskite materials in optoelectronic devices.

Improving the stability of all‐inorganic halide perovskite nanocrystals has become an urgent task that cannot be ignored in practical applications. Lead halide perovskite CsPbX3 (X = Br, I, Cl) compounds are considered as the potential materials for next‐generation light‐emitting devices due to their superior optical properties. However, they are threatened by thermal degradation and atmospheric moisture. In order to better solve this practical problem, CsPbBr3 quantum dots (QDs) and CsPbBr3@Cs4PbBr6 nanocrystals (NCs) are tested under heating and cooling cycles, and the photoluminescence (PL) intensity loss of different perovskite materials at high temperatures is investigated. In addition, a thermoplastic polyurethane encapsulation strategy is proposed to improve their properties of thermal degradation and moisture resistance. This inexpensive and convenient method not only greatly reduces the PL intensity loss, but also shows excellent PL performance even in water. The encapsulated material has both flexible and elastic properties, which paves the way for the next commercial processing of all inorganic perovskite materials.

Ensuring the stability of all‐inorganic halide perovskite light‐emitting diodes (LEDs) has become an obstacle that needs to be broken for commercial applications. Currently, lead halide perovskite CsPbX3 (X = Br, I, Cl) nanocrystals (NCs) are considered as alternative materials for future fluorescent lighting devices due to their combination of superior optical and electronic properties. However, the temperature of the surface of the LEDs will increase after long‐term power‐on work, which greatly affects the optical stability of CsPbX3 NCs. In order to overcome this bottleneck issue, a strategy of annealing perovskite materials in liquid is proposed, and the changes in photoluminescence and electroluminescence (EL) behaviors before and after annealing are studied. The results show that the luminescence stability of the annealed perovskite materials is significantly improved. Moreover, the EL stability of different perovskite LED devices under long‐term operation is monitored, and the performance of the annealed materials is particularly outstanding. The results have proved that this convenient and low‐cost liquid annealing strategy is suitable for large‐scale postprocessing of perovskite materials, granting them stable fluorescence emission, which will bring a new dawn to the commercialization of next‐generation optoelectronic devices.

AgNbO3 exhibits “peculiar” anti-/ferroelectricity and narrow bandgap semi-conductivity that leads to active responses to different types of external stimuli, including electric fields, light and mechanical forces. Some of these unique...

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