Highly luminescent inks are desirable for various applications such as decorative coating, art painting, and anticounterfeiting, to name a few. However, present inks display low photoluminescent efficiency requiring a strong excitation light to make them glow. Here, we report a highly luminescent ink based on the copper-iodide/1-Propyl-1,4-diazabicyclo[2.2.2]octan-1ium (Cu 4 I 6 (pr-ted) 2 ) hybrid cluster with a quantum efficiency exceeding 98%. Under the interaction between the Cu 4 I 6 (pr-ted) 2 hybrid cluster and polyvinylpyrrolidone (PVP), the highly luminescent Cu 4 I 6 (pr-ted) 2 /PVP ink can be facilely prepared via the onepot solution synthesis. The obtained ink exhibits strong green light emission that originates from the efficient phosphorescence of Cu 4 I 6 (pr-ted) 2 nanocrystals. Attractively, the ink displays high conversion efficiency for the ultraviolet light to bright green light emission due to its wide Stokes shift, implying great potential for anticounterfeiting and luminescent solar concentrator coating.

Aggregation-induced emission (AIE) is an attractive phenomenon in which materials display strong luminescence in the aggregated solid states rather than in the conventional dissolved molecular states. However, highly luminescent inks based on AIE are hard to be obtained because of the difficulty in finely controlling the crystallinity of AIE materials at nanoscale. Herein, we report the preparation of highly luminescent inks via oil-in-water microemulsion induced aggregation of Cu-I hybrid clusters based on the highly soluble copper iodide-tris(3-methylphenyl)phosphine (Cu I (P-(m-Tol) ) ) hybrid. Furthermore, we can synthesize a series of AIE inks with different light-emission colors to cover the whole visible spectrum range via a facile ligand exchange processes. The assemblies of Cu-I hybrid clusters with AIE characteristics will pave the way to fabricate low-cost highly luminescent inks.

Aqueous proton batteries are regarded as one of the most promising energy technologies for next-generation grid storage due to the distinctive merits of H+ charge carriers with small ionic radius and light weight. Various materials have been explored for aqueous proton batteries; however, their full batteries show undesirable electrochemical performance with limited rate capability and cycling stability. Here we introduce a novel aqueous proton full battery that shows remarkable rate capability, cycling stability, and ultralow temperature performance, which is driven by a hydrogen gas anode and a Prussian blue analogue cathode in a concentrated phosphoric acid electrolyte. Its operation involves hydrogen evolution/oxidation redox reactions on the anode and H+ insertion/extraction reactions on the cathode, in parallel with the ideal transfer of only H+ between these two electrodes. The fabricated aqueous hydrogen gas–proton battery exhibits an unprecedented charge/discharge capability of up to 960 C with a superior power density of 36.5 kW kg–1, along with an ultralong cycle life of over 0.35 million cycles. Furthermore, this hydrogen gas–proton battery is able to work well at an ultralow temperature of −80 °C with 54% of its room-temperature capacity and under −60 °C with a stable cycle life of 1150 cycles. This work provides new opportunities to construct aqueous proton batteries with high performance in extreme conditions for large-scale energy storage.

Metal halide perovskites are emerging as promising candidate materials for light-emitting diodes (LEDs) due to their high luminescence, color purity, tunable bandgaps, and solution processabilities. In the past several years, the metal halide perovskite based LEDs (PeLEDs) in the green and red light spectral range have been demonstrated in high brightness and good efficiency. However, the performance of blue PeLED is still limited by the low blue light emission efficiency of present metal halide perovskite materials. Here, we report a facile solution method to fabricate a series of quasi-2D CsPbBr x Cl 3−x perovskite films with high photoluminescent quantum yields (PLQYs) in the blue light spectral range. By compositional engineering via increasing the content of chloride, we achieved the tunable light emission wavelength of quasi-2D CsPbBr x Cl 3−x perovskite films from green (504 nm) to blue (470 nm) with a high PLQY up to 42% at 486 nm. In addition, we developed a novel NiO x /LiF hole transport layer with high affinity to precursor solution for improving the film quality of quasi-2D CsPbBr x Cl 3-x perovskite while reducing the quenching effect of hole transport layer to as-formed perovskite film. As a result, the blue PeLEDs based on quasi-2D CsPbBr x Cl 3-x perovskite films show color-tunable emissions and the external quantum efficiency of 0.52% as well as high brightness of 1446 cd m −2 are achieved at 490 nm.