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Lead halide perovskites have multiple optoelectronic functions because of their intriguing photophysical properties. Unfortunately, their extensive application prospects are limited by their high toxicity and instability. For these reasons, it is significant to assemble novel lead-free halides with high-performance luminescence properties. Environment-friendly In3+-based halides are gaining increasing interest because of their high stabilities and photoluminescence quantum yields (PLQYs). In this research work, we synthesized a zero-dimensional (0D) hybrid indium chloride single crystal of [1-Me-Pipz]2[InCl6]Cl·H2O (1-Me-Pipz = protonated 1-methylpiperazine) that demonstrated strong self-trapped exciton (STE)-associated broadband yellow light emission with a sufficient PLQY of 51.58%. Moreover, [1-Me-Pipz]2[InCl6]Cl·H2O exhibits extremely excellent structural and spectral stability in a variety of harsh environments. Importantly, the outstanding optoelectronic characteristics allow indium perovskite to be used for the successful fabrication of white light-emitting diodes (WLEDs) with a high color rendering index of 86.4. This work enriches the literature on indium halide perovskites and provides a novel viewpoint for the possible applications of 0D In3+ perovskite-based luminescent materials. [ABSTRACT FROM AUTHOR]

Despite the extraordinary X‐ray scintillation performance of three‐dimensional (3D) lead perovskite nanocrystals (PNCs), the serious biotoxicity of Pb2+ and luminescent instability in water remain insurmountable obstacles for their applications in medical imaging. To address these drawbacks, herein, the study demonstrates one new lead‐free zero‐dimensional (0D) hybrid cuprous halide of single‐crystalline [BzTPP]2Cu2I4 (BzTPP = Benzyltriphenylphosphonium) as a satisfactory X‐ray scintillator. [BzTPP]2Cu2I4 displays broadband yellowish‐green light emission with a high photoluminescent quantum yield (PLQY) of 44.2% and large Stokes shift of 167 nm upon UV light excitation. High PLQY and negligible self‐absorption enable [BzTPP]2Cu2I4 to display impressive scintillation performance excited by X‐ray with a light yield of 27 706 photons MeV‐1 and low detection limit of 0.352 µGy s−1, surpassing typical 3D PNCs. More importantly, [BzTPP]2Cu2I4 represents extraordinary structural and luminescent stability in water for at least one month. The excellent and stable radioluminescence performance as well as solution growth method ensure a [BzTPP]2Cu2I4‐based screen for fine‐resolution X‐ray imaging with potential in radiography and inspection. This work highlights the multiple merits of low‐toxicity and cost, high light yield, and long‐term water‐stability of 0D hybrid cuprous halides as highly desirable X‐ray scintillators. [ABSTRACT FROM AUTHOR]

Despite the ultra‐high photoluminescence quantum yield (PLQY) of 0D hybrid manganese halides as state‐of‐the‐art luminescent materials, intrinsic water stability remains an unsurpassable barrier due to the serious hygroscopicity of the hydrogen‐bonding structure. Herein, a synthetic strategy that realizes adjustable emission color and high water resistance in a 0D hybrid manganese chloride family based on the same cation of [H2TMDAP]2+ (TMDAP = N,N,N′,N′‐tetramethyl‐1,3‐diaminopropane) is reported. Specifically, direct solution or solid‐state reaction of precursor materials generates [H2TMDAP]3[MnCl4]2[Mn2Cl6], while additional Zn2+‐doping as a structural directing agent results in [H2TMDAP]Mn0.63Zn0.37Cl4. Functionally, the [Mn/ZnCl4]2− tetrahedron based [H2TMDAP]Mn0.63Zn0.37Cl4 displays green light emission at 521 nm with a PLQY of 63.9%. [H2TMDAP]3[MnCl4]2[Mn2Cl6] is composed of a [MnCl6]4− octahedron based [Mn2Cl6]2− chain and a discrete [MnCl4]2− tetrahedron, but it only exhibits single red emission at 628 nm with a PLQY of 48.1%. Compared with water‐instable [H2TMDAP]Mn0.63Zn0.37Cl4, [H2TMDAP]3[MnCl4]2[Mn2Cl6] represents extraordinary chemical stability in humid air and water over 1 month, manifested by an unchanged structural lattice and sufficient emission intensity. Significantly, the ultra‐high water proof performance of [H2TMDAP]3[MnCl4]2[Mn2Cl6] is nearly unmatchable among all previously reported manganese halides as far as is known. The combined merits of tunable emission wavelength, high PLQY, and stability highlight the potential applications of title materials in solid‐state lighting and display diodes. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescence (CPL) with polychromatic colors has been widely studied due to its great applications in chiroptical, optoelectronics, and spintronics. However, the realization of white CPL in single‐component solid‐state materials remains a great challenge and suffers from the incompatibility between high efficient luminescence and large asymmetric discrimination. Here, by exploiting self‐trapped exciton mechanism and chirality induction strategy, a pair of 1D chiral perovskites, (RR/SS‐DMPZ)PbBr4 (where DMPZ = cis‐2,5‐dimethylpiperazine divalent cation), is reported to achieve white CPL with both high quantum yield of 28.4% and large photoluminescence asymmetry factor |glum| of 2.32 × 10−2. The crystal structures are featured by 1D double‐chain structure composed of distorted octahedra with short PbPb distances as the structural origin of the high photoluminescence yield. The high |glum| value is caused by efficient chiral induction due to the multiple hydrogen bonds between the chiral host composed of the enantiopure organic cations containing two stereocenters and the inorganic emitting guest. The self‐trapped exciton emission mechanism is demonstrated by density functional theory calculations and variable‐temperature photoluminescence and femtosecond‐transient absorption spectroscopy studies. The photo‐luminescent white light‐emitting diodes exhibit good stability and can be used as single‐component white light emitters. This work provides applicable strategies to explore single‐component white CPL emitters. [ABSTRACT FROM AUTHOR]

Despite remarkable luminescent performance of 0D lead halide perovskites, achieving highly efficient blue light emission is extremely challenging and crucial for this domain. Considering the high toxicity of Pb2+ ion, it is significant to explore water‐stable lead‐free 0D halides as highly efficient and stable blue emitting materials. To address these issues, a family of 0D hybrid zinc halides of AZnBr4 (A = EP, BP, and TMPDA) based on discrete [ZnBr4]2− tetrahedrons is herein reported as desirable blue light emitters. The wide band gaps enable these 0D halides to display highly efficient blue light emissions (452–485 nm) with highest photoluminescence quantum yield (PLQY) of 35.47%. More importantly, all these 0D halides present extraordinary chemical stabilities in humid air and water for one month, and are also capable of withstanding extreme pH conditions in the range of 0–14, likely the widest observed pH range for perovskites. Notably, the ultrahigh chemical stabilities of 0D zinc halides are nearly unmatchable among all known literature perovskite materials to the best of the authors' knowledge. Combined superiorities of unusual blue light emission, promising PLQY, ultrahigh stability, and non‐toxicity highlight the potential optoelectronic applications in wide chemical environments for these 0D zinc halides. [ABSTRACT FROM AUTHOR]

Recently, zero‐dimensional (0D) hybrid metal halides have attracted intensive attention with wide applications in solid‐state lighting and display diodes. Herein, by using a facile wet‐chemistry method, we prepared one new 0D hybrid antimony halide of [HMHQ]2SbCl5 ⋅ 2H2O (MHQ=2‐methyl‐8‐hydroxyquinoline) based on the discrete [SbCl5]2− unit. Remarkably, the bulk crystals of [HMHQ]2SbCl5 ⋅ 2H2O exhibit strong cyan light emission with a promising photoluminescence quantum yield (PLQY) of 18.92%. Systematical studies disclose that the cyan emission is mainly derived from the radiative recombination within conjugated organic cation. Benefiting from the promising luminescent performance, this 0D antimony halide can be utilized as an excellent down‐conversion light emitting luminescent material to assemble white light‐emitting diodes with high color rendering index (CRI) of 90.2. [ABSTRACT FROM AUTHOR]

Mn2+ doped colloidal three‐dimensional (3D) lead halide perovskite nanocrystal (PNC) has attracted intensive research attention; however, the low exciton binding energy and fatal optical instability of 3D PNC seriously hinder the optoelectronic application. Therefore, it remains significant to explore new stable host perovskite with strongly bound exciton to realize more desirable luminescent property. In this work, we utilized bulk one‐dimensional (1D) hybrid perovskite of [AEP]PbBr5 ⋅ H2O (AEP=N‐aminoethylpiperazine) as structural platform to rationally optimize the luminescent property by a controllable Mn2+ doping strategy. Significantly, the series of Mn2+‐doped 1D [AEP]PbBr5 ⋅ H2O show enhanced energy transfer efficiency from the strongly bound excitons of host material to 3d electrons of Mn2+ ions, resulting in tunable broadband light emissions from weak yellow to strong red spectral range with highest photoluminescence quantum yield up to 28.41 %. More importantly, these Mn2+‐doped 1D perovskites display ultrahigh structural and optical stabilities in humid atmosphere, water and high temperature exceeding the conventional 3D PNC. Combined highly efficient, tunable and stable broadband light emissions enable Mn2+‐doped 1D perovskite as excellent down‐converting phosphor showcasing the potential application in white light emitting diode. This work not only provides a profound understanding of low‐dimensional perovskites but also opens a new way to rationally design high‐performance broadband light emitting perovskites for solid‐state lighting and displaying devices. [ABSTRACT FROM AUTHOR]

Rationally optimizing the photoluminescence performance via accurate structural modulation is one of most important and challenging issues for hybrid halides. Herein, a viable crystal dimensional reduction strategy is proposed to reasonably enhance the photoluminescence quantum yield (PLQY) of hybrid antimony halide. Specifically, a synthetic technique is developed and new 1D [DMPZ]SbCl5 ∙ H2O (DP‐SbCl5) is sliced to 0D [DMPZ]2SbCl6 ∙ Cl ∙ (H2O)2 (DP‐SbCl6) with crystal dimensional reduction from infinite [SbCl5]2− chain to discrete [SbCl6]3− octahedron. Comparing with nonluminescent 1D DP‐SbCl5, 0D DP‐SbCl6 displays highly efficient broadband yellow light emission with enhanced PLQY up to 75.94%. First‐principles calculation demonstrates that 0D DP‐SbCl6 features more flat and narrow band structure, which promotes the photoelectron localization and increases the quantum confinement, and finally boosts the luminescence efficiency. Together highly efficient and ultra‐stable luminescence performance enable DP‐SbCl6 as excellent down‐conversion broadband yellow phosphor to successfully fabricate white light emitting diodes with a high color rendering index of 92. This work provides a novel structural modulation strategy of crystal dimensional reduction to rationally optimize the PL performance of hybrid metal halides. [ABSTRACT FROM AUTHOR]

In recent years, organic–inorganic hybrid metal halides have emerged as a highly promising class of semiconducting light emitting diodes (LEDs) due to their fascinating photoluminescence properties. Here, by specifically selecting different organic cations as templates, a series of new hybrid cuprous halides have been solvothermally prepared, namely [Me-Py]CuI2 (1), [(Me)2-DABCO]Cu2I4 (2), [Me-MePy]Cu2I3 (3), and [H2DABCO]Cu3X5 (X = I (4) and Br (5)). These hybrid cuprous halides feature one-dimensional (1D) [CuI2]−, [Cu2I3]− and [Cu3X5]2− (X = Br, I) chains surrounded and charge-balanced by organic cations. Under UV photoexcitation, these hybrid cuprous halides exhibit strong tunable photoluminescence from cyan (480 nm) to red (675 nm) emissions with large Stokes shifts (345 nm). The intrinsic nature of PL emissions is also investigated based on temperature-dependent PL emission, lifetime, photoluminescence quantum efficiencies, etc. [ABSTRACT FROM AUTHOR]

Organic-inorganic hybrid low-dimensional metal halides have been widely studied as a new class of luminescence materials due to abundant structural diversity and intriguing photophysical property. Herein, we explored two new Cd-based 0D halides of [BHEPZ]CdBr 4 (BHEPZ = 1,4-Bis(2-hydroxyethyl) piperazine) and [EPIPZ]CdBr 4 (EPIPZ = 1-ethylpiperazine) through facile wet-chemistry method. These 0D halides exhibit blue light emissions derived from radiative recombination of self-trapped excitons (STEs) based on detailed spectroscopy investigations. More interestingly, [BHEPZ]CdBr 4 exhibits rapid luminescence off switching toward benzaldehyde but fails in any other organic solvents. In-depth investigations demonstrate that the detection limit can fall to 2.65 ppm indicating perfect real-time fluorescent probe to detect benzaldehyde with high sensitivity and selectivity. This work enriches the cadmium halide materials and provide a new perspective for potential applications of 0D hybrid metal halides. Two Cd-based 0D halides were designed as blue light emitters from self-trapped excitons (STEs) with high thermal stability. Significantly, this halide displays fluorescence detection ability toward benzaldehyde with high selectivity, sensitivity and stability. [Display omitted] • Two 0D hybrid cadmium halides based on discrete [CdBr 4 ]2- clusters were synthesized. • The halides exhibits excellent chemical and thermal stabilities. • [BHEPZ]CdBr 4 can be explored as a good fluorescence sensor for benzaldehyde. [ABSTRACT FROM AUTHOR]

One new bulk lead-free 0D antimony halide of [DPA] 3 SbCl 6 was designed as greenish-yellow light emitter with near-unity PLQY. Thorugh elaborate fabrication toward [DPA] 3 SbCl 6 , multiple reversible photoluminescence on/off switch was achieved with important potential in anti-counterfeiting and confidential information encryption-decryption technologies, which opens a new way to design perovskite materials for new optoelectronic applications. [Display omitted] • New 0D antimony halide as efficient green emitter with remarkable near-unity PLQY. • Applied as luminescent ink against high-resolution anti-counterfeiting application. • Fast information encryption decryption achieved through solid/liquid dual mode. • Multiple reversible PL on/off switches enhancement information encryption decryption. Storage and protection of confidential information is an increasing challenge for global digital economy, which stimulates the never-ending pursuit of high-security technology to prevent information forgery and leakage. Herein, we develop a novel approach to realize controllable information encryption-decryption based on reversible photoluminescence (PL) on/off switch in 0D hybrid antimony halide. A new 0D [DPA] 3 SbCl 6 (DPA = dipropylamine) was designed as broadband green light emitter with near-unity photoluminescence quantum yield. Benefiting from invisible and non-luminescent superiorities of SbCl 3 , information encrypted by SbCl 3 pattern can′t be directly decoded upon common light excitations. Under the trigger of [DPA]Cl salt, superfast transition from SbCl 3 to [DPA] 3 SbCl 6 gives rise to highly efficient emission and thus effective information decoding. Subsequently, through methanol impregnation and desolvation strategy, luminescence of [DPA] 3 SbCl 6 can be easily quenched and recovered resulting in reversible PL on/off switching. The multiple and controllable PL emission conversion provides a dual-mode confidential information encryption-decryption technology. [ABSTRACT FROM AUTHOR]