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All‐inorganic metal halides with afterglow emission have attracted increasing attention due to their significantly longer afterglow duration and higher stability compared to their organic–inorganic hybrid counterparts. However, their afterglow colors have not yet reached the blue spectral region. Here, we report all‐inorganic copper‐doped Rb2AgBr3 single crystals with ultralong blue afterglow (>300 s) by modulating defect states through doping engineering. The introduction of copper(I) ions into Rb2AgBr3 facilitates the formation of bromine vacancies, thus increasing the density of trap states available for charge storage and enabling bright, persistent emission after ceasing the excitation. Moreover, cascade energy transfer between distinct emissive centers in the crystals results in ultra‐broadband photoluminescence, not only covering the whole white light with near‐unity quantum yield but also extending into the near‐infrared region. This 'cocktail' of exotic light‐emission properties, in conjunction with the excellent stability of copper‐doped Rb2AgBr3 crystals, allowed us to demonstrate their implementation to solid‐state lighting, night vision, and intelligent anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

DNA‐stabilized silver nanoclusters (DNA‐AgNCs) are easily tunable emitters with intriguing photophysical properties. Here, a DNA‐AgNC with dual emission in the red and near‐infrared (NIR) regions is presented. Mass spectrometry data showed that two DNA strands stabilize 18 silver atoms with a nanocluster charge of 12+. Besides determining the composition and charge of DNA2[Ag18]12+, steady‐state and time‐resolved methods were applied to characterize the picosecond red fluorescence and the relatively intense microsecond‐lived NIR luminescence. During this process, the luminescence‐to‐fluorescence ratio was found to be excitation‐intensity‐dependent. This peculiar feature is very rare for molecular emitters and allows the use of DNA2[Ag18]12+ as a nanoscale excitation intensity probe. For this purpose, calibration curves were constructed using three different approaches based either on steady‐state or time‐resolved emission measurements. The results showed that processes like thermally activated delayed fluorescence (TADF) or photon upconversion through triplet‐triplet annihilation (TTA) could be excluded for DNA2[Ag18]12+. We, therefore, speculate that the ratiometric excitation intensity response could be the result of optically activated delayed fluorescence. [ABSTRACT FROM AUTHOR]

Double perovskites (DPs) are one of the most promising candidates for developing white light‐emitting diodes (WLEDs) owing to their intrinsic broadband emission from self‐trapped excitons (STEs). Translation of three‐dimensional (3D) DPs to one‐dimensional (1D) analogues, which could break the octahedral tolerance factor limit, is so far remaining unexplored. Herein, by employing a fluorinated organic cation, we report a series of highly luminescent 1D DP‐inspired materials, (DFPD)2MIInBr6 (DFPD=4,4‐difluoropiperidinium, MI=K+ and Rb+). Highly efficient warm‐white photoluminescence quantum yield of 92 % is achieved by doping 0.3 % Sb3+ in (DFPD)2KInBr6. Furthermore, single‐component warm‐WLEDs fabricated with (DFPD)2KInBr6:Sb yield a luminance of 300 cd/m2, which is one of the best‐performing lead‐free metal‐halides WLEDs reported so far. Our study expands the scope of In‐based metal‐halides from 3D to 1D, which exhibit superior optical performances and broad application prospects. [ABSTRACT FROM AUTHOR]

Triplet exciton‐based long‐lived phosphorescence is severely limited by the thermal quenching at high temperature. Herein, we propose a novel strategy based on the energy transfer from triplet self‐trapped excitons to Mn2+ dopants in solution‐processed perovskite CsCdCl3. It is found the Mn2+ doped hexagonal phase CsCdCl3 could simultaneously exhibit high emission efficiency (81.5 %) and long afterglow duration time (150 s). Besides, the afterglow emission exhibits anti‐thermal quenching from 300 to 400 K. In‐depth charge‐carrier dynamics studies and density functional theory (DFT) calculation provide unambiguous evidence that carrier detrapping from trap states (mainly induced by Cl vacancy) to localized emission centers ([MnCl6]4−) is responsible for the afterglow emission with anti‐thermal quenching. Enlightened by the present results, we demonstrate the application of the developed materials for optical storage and logic operation applications. [ABSTRACT FROM AUTHOR]

Lead‐free halide perovskites have triggered interest in the field of optoelectronics and photocatalysis because of their low toxicity, and tunable optical and charge‐carrier properties. From an application point of view, it is desirable to develop stable multifunctional lead‐free halide perovskites. We have developed a series of Cs2PtxSn1−xCl6 perovskites (0≤x≤1) with high stability, which show switchable photoluminescence and photocatalytic functions by varying the amount of Pt4+ substitution. A Cs2PtxSn1−xCl6 solid solution with a dominant proportion of Pt4+ shows broadband photoluminescence with a lifetime on the microsecond timescale. A Cs2PtxSn1−xCl6 solid solution with a small amount of Pt4+ substitution exhibits photocatalytic hydrogen evolution activity. An optical spectroscopy study reveals that the switch between photoluminescence and photocatalysis functions is controlled by sub‐band gap states. Our finding provides a new way to develop lead‐free multifunctional halide perovskites with high stability. [ABSTRACT FROM AUTHOR]

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Film, One-Dimensional Double Perovskite, Self-Trapped Emission, Warm White-Light-Emitting Diodes In their Research Article (e202213240), Feng Liu, Bin Yang, and co-workers report a novel highly luminescent one-dimensional double-perovskite-inspired material with a warm-white photoluminescence quantum yield of 92 %. Keywords: Film; One-Dimensional Double Perovskite; Self-Trapped Emission; Warm White-Light-Emitting Diodes EN Film One-Dimensional Double Perovskite Self-Trapped Emission Warm White-Light-Emitting Diodes 1 1 1 01/04/23 20230109 NES 230109 B Double perovskites b are one of the most promising candidates for developing white-light-emitting diodes owing to their intrinsic broadband emission from self-trapped excitons. [Extracted from the article]