Search

Despite rapid progress and wide applications of room temperature phosphorescence (RTP) materials, it is still a great challenge to optimize the RTP activity through rational structural design at a molecular level. Herein, a successful cationic engineering strategy is demonstrated to modulate the crystal flexibility achieving controllable RTP in a new pair of metal halides [APML]ZnCl4 ([APML] = N‐(3‐Aminopropyl)morpholine) and [AEML]ZnCl4 ([AEML] = N‐(2‐Aminoethyl)morpholine). Both halides display blue fluorescence under 365 nm UV. Comparing with longer [APML]+, shorter [AEML]+ significantly enhances crystal rigidity and restrains non‐radiative scattering, boosting photoluminescence quantum yield (PLQY) from 18.89% to 22.41%. Synchronously, enhanced crystal rigidity significantly promotes the inter‐system crossing from singlet to triplet excited states. As a consequence, [AEML]ZnCl4 displays long‐lived green RTP property with millisecond scale lifetime in contrast to the blank RTP activity of [APML]ZnCl4. Comprehensive investigations demonstrate that the energy transfer between inorganic and organic components greatly changes the redistribution of singlet and triplet excited states, resulting in distinct phosphorescence activity. The different short‐lived blue fluorescence and long‐lived green phosphorescence provide a color‐time‐dual‐resolved luminescent tag with advanced applications in anti‐counterfeiting, etc. This work highlights a new structural engineering strategy to achieve controllable RTP affording a guide to rationally design RTP materials. [ABSTRACT FROM AUTHOR]

Although the luminescent performance of organic–inorganic metal halides (OIMHs) have obtained significant advances, achieving intrinsic water‐stable OIMHs remain a substantial challenge due to the fragile ionic nature of hybrid the halide structure. To overcome these challenges, a structural design strategy is proposed that involves the use of highly hydrophobic cations as a protective layer to improve the water stability of OIMH. Herein, an aprotic trimethylsulfoxonium [TMSO]+ is selected as a hydrophobic cation and successfully assemble two new manganese based OIMHs of (TMSO)MnCl3 and (TMSO)MnBr3 through facile solid and liquid phase reaction methods. Remarkably, these halides exhibit strong red light emissions with high quantum yields recorded at 86.1% and 53.4%, respectively, originating from the octahedral [MnX6]4− based one‐dimensional (1D) [MnX3]− chain. Most significantly, these halides present extraordinary structural and luminescent stabilities toward continuous corrosion by humid air, water, and acid‐aqueous solution for more than one month, suggesting promising application prospects in extreme chemical environments. In‐depth Hirshfeld surface calculations demonstrate that the ultrahigh water‐stability benefits from the abundant hydrogen bonds and strong electrostatic interactions between [TMSO]+ and [MnX3]− ions, which provides an underlying insight into the stability mechanism. This water‐stability enhancement strategy represents a breakthrough structural engineering to rationally design more water‐stable OIMH. [ABSTRACT FROM AUTHOR]

Considering the instability and toxicity of 3D Pb-based perovskite nanocrystals, lead-free low-dimensional organic–inorganic hybrid metal halides have attracted widespread attention as potential substitutes. Herein, two new tin-based 0D halides [H4BAPP]SnBr5·Br and [H4BAPP]SnCl5·Cl·H2O (BAPP = 1,4-bis(3-aminopropyl)piperazine) were synthesized successfully based on [SnX5]3− as an emission center. Typically, [H4BAPP]SnBr5·Br and [H4BAPP]SnCl5·Cl·H2O display broadband yellow and yellow-green light emissions originating from the radiative recombination of self-trapped excitons (STEs). The photoluminescence quantum yields (PLQYs) of the two compounds were calculated to be 19.27% and 2.36%, respectively. Furthermore, the excellent chemical and thermal stability and broadband light emissions reveal their potential application in solid-state white lighting diodes. [ABSTRACT FROM AUTHOR]

Environmentally friendly and highly efficient blue luminescent materials are an unremitting pursuit in the optoelectronic field. Herein, we assembled a new 0D lead-free metal halide of (F-PPA)ZnBr4, which exhibits narrow blue light emission with a remarkable PLQY of 50.15%, high stability and high detection sensitivity toward UV light. These results indicate the potential for the application of low-dimensional zinc-based halides in multiple optoelectronic devices. [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]

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]

Herein, we for the first time report a reversible conversion between green-emissive [DMPZ]MnCl4 and red-emissive [DMPZ]4(MnCl6)(MnCl4)2·(H2O)2 (DMPZ = 1,4-dimethylpiperazine) using kinetic and thermodynamic controlling strategies. Significantly, the synchronous structural and emission transformations in single-component organic manganese halides with adjustable emission colors are highlighted. [ABSTRACT FROM AUTHOR]

In the relentless pursuit of developing high-performance, stable and environmentally friendly materials for X-ray detection, we present a new class of Bi-based hybrid organic–inorganic perovskites. An X-ray detector based on a new zero-dimensional (0D) triiodide-induced lead-free hybrid perovskite, (DPA)2BiI9 (DPA = C5H16N22+), has been developed demonstrating outstanding detection performance, including high X-ray sensitivity (20 570 μC Gyair−1 cm−2), low detectable dose rate (0.98 nGyair s−1), fast response time (154/162 ns) and excellent long-term stability. [ABSTRACT FROM AUTHOR]

Herein, we report two hybrid zero‐dimensional (0D) lead‐free metal oxide halides of [PPip]Sb2Cl6O (1) ([PPip]=1‐(2‐Pyridyl)piperazine) and [PmPip]Sb2Cl6O (2) ([PmPip]=1‐(2‐Pyrimidyl)piperazine). Compounds 1 and 2 are able to exhibit narrow blue light emissions excited by UV light with photo‐luminescence quantum yields (PLQYs) of 25.49 % and 24.71 %, respectively. Through systematical characterizations, these blue light emissions can be attributed to the radiative transition in conjugated organic cations. Benefiting from the highly efficient intrinsic blue emissions, compound 2 can be used as blue fluorophor to fabricate liquid crystal display. This work provides a new to assembly blue emitter through by virtue of the optical active organic cations in hybrid materials. [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]

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]

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]

A convenient and rapid detection method for methanol in ethanol remains a major challenge due to their indistinguishable physical properties. Herein, a novel fluorescence probe based on perovskite was successfully designed to overcome this bottleneck. We report a new zero‐dimensional (0D) hybrid perovskite of [MP]2InxSb1−xCl7 ⋅ 6 H2O (MP=2‐methylpiperazine) displaying an unusual green light emission with near‐unity photoluminescence quantum yield. Remarkably, this 0D perovskite exhibits reversible methanol‐response luminescence switching between green and yellow color but fail in any other organic vapors. Even for blended alcohol solutions, the luminescent probe exhibits excellent sensing performance with multiple superiorities of rapid response time (30 s) and ultra‐low detection limit (40 ppm), etc. Therefore, this 0D perovskite can be utilized as a perfect fluorescence probe to detect traces of methanol from ethanol with ultrahigh sensitivity, selectivity and repeatability. To the best of our knowledge, this work represents the first perovskite as fluorescence probe for methanol with wide potential in environmental monitoring and methanol detection, etc. [ABSTRACT FROM AUTHOR]

Two new zero-dimensional (0D) hybrid indium halides of [H2DMP]2InX7·2H2O (X = Cl, Br) were designed based on [InX6]3− octahedra as optically active centers. Remarkably, these 0D halides display intrinsic broadband yellow-orange light emissions with highest quantum yield of 58.53% exceeding all previously reported 0D indium halides. [ABSTRACT FROM AUTHOR]

Hybrid organic–inorganic lead halide perovskites (HOIPs) possess significant photoelectric characteristics for solar energy conversion, but the presence of lead causes issues for eco-friendly applications. Halide double perovskites represent a green option for application in the optoelectronic field, especially X-ray detection systems. Despite the great efforts, the exploration of large-size lead-free iodide-based hybrid double perovskite single crystals for X-ray detection has been unsuccessful. Herein, we demonstrate that a large single crystal of the 2D (two-dimensional) semiconducting perovskite (C6H16N2)2CuBiI8·0.5H2O can serve as an X-ray detection candidate. A perovskite crystal, as large as 35 × 31 × 3 mm3, was grown using a low-cost, simple cooling solution approach. To the best of our knowledge, this is the first time a centimeter-sized 2D BiCu iodide double perovskite single crystal has been used for X-ray detection. The perovskite crystal exhibited unique properties for X-ray detection, such as a significant X-ray absorption coefficient, considerable μτ product, and low trap density. Moreover, X-ray detection with a sensitivity of 5.51 μC Gyair−1 cm−2 was achieved based on a single crystal. This work opens new ways to explore specially designed organic cations for stabilizing 2D HOIPs that show great potential in optoelectronics. [ABSTRACT FROM AUTHOR]

X-ray detection plays an extremely significant function in medical diagnosis, nondestructive testing, safety testing, scientific research, environmental monitoring and other practical applications. However, conventional inorganic semiconductors, such as amorphous selenium, crystalline Si and pure Ge present almost uncontrollable bandgaps and require quite sophisticated fabrication techniques despite their outstanding performance. As developing materials for direct conversion X-ray detection, halide perovskite semiconductors exhibit remarkable properties with high sensitivity. In this review, we summarize the optoelectronic performance of different dimensional perovskites in X-ray detection and their application in X-ray imaging for perovskite-based X-ray detectors including single crystals, films and wafers. This review aims to preliminarily highlight the relationship between structural dimensionality and X-ray detection properties, which should provide valuable suggestions for researchers to rationally design high-performance halide perovskite X-ray photodetectors through crystal engineering at the molecular level in the future. [ABSTRACT FROM AUTHOR]

The concentration-caused quenching (CCQ) effect seriously deteriorates the photoluminescence (PL) efficiency of 0D organic–inorganic hybrid halide perovskites but reasonable management of CCQ via accurate structural design strategies remains a formidable challenge for PL property optimization. Herein, by fine-tuning the geometric configurations of organic cations, a controllable PL quenching-activation switch is realized by accurately modulating the CCQ effect. Specifically, we rationally designed a couple of 0D antimony halides, namely [BPP]SbCl5 (BPP = 1,3-bis(4-pyridyl)-propane) and [BPPP]SbCl5 (BPPP = 1,3-bis(4-piperidyl)-propane), based on the same [SbCl5]2− units. Through purposive structural regulation from the closely confined [BPP]2+ to the incompact [BPPP]2+ matrix, the concentration of the fluorescent [SbCl5]2− species and the CCQ effect were notably diminished, which significantly promoted the localization degree of the photoelectrons. Hence, [BPPP]SbCl5 displays enhanced broadband yellow light emission with a high photoluminescence quantum yield of 79.57%, while [BPP]SbCl5 is completely non-luminescent. In addition, by virtue of the PL inactivation–activation conversion in the superfast assembly process from SbCl3 to [BPPP]SbCl5, secret information encrypted by an invisible printed SbCl3 pattern can be rapidly decrypted by the light-emissive [BPPP]SbCl5 under the trigger of an organic precursor, which showcases the potential in confidential information encryption–decryption technology. [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]

An ultrapure green phosphor with narrow emission range (525–535 nm) and full width at half maximum (FWHM < 25 nm) is critical for a backlit light-emitting diode to realize an ultrawide color gamut in liquid-crystal display (LCD), according to the Rec. 2020 standard. However, it is extremely formidable to achieve this goal for low-dimensional halide perovskites (LDHPs), which readily display broadband emissions arising from self-trapped excitons due to strong electron–phonon coupling. Herein, we report a new one-dimensional (1D) hybrid lead halide of [TMPDA]2Pb3Br10 (TMPDA = tetramethyl-1,3-diaminopropane) displaying unusual ultrapure green light emission. Benefiting from the synergistic work of weak electron–phonon interaction and strong quantum confinement, this 1D halide displays sharp green emission at 526 nm with narrow FWHM (25 nm), high photoluminescence quantum yield (71.95%) and color purity (91.1%), which achieves the Rec. 2020 standard and represents the purest green emitting LDHP to date. Remarkably, as a down-conversion green phosphor, [TMPDA]2Pb3Br10 provides an ultrawide color gamut covering 121.5% of NTSC and 90.7% of Rec. 2020 standards, showcasing the application in high-resolved LCD. The establishment of a fundamental structure–property relationship also paves a new way to rationally design novel narrow-band emitting LDHPs as a supplement of colloidal 3D perovskite nanostructures. [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]

A facile, green and economical preparation technique is critical for the cost-effective scale-up manufacture and optoelectronic device engineering of halide perovskites. Herein, we developed a viable solvent-free mechanochemical synthetic route to systematically prepare organic–inorganic hybrid perovskites. In this work, an enormous halide library comprising 16 zero-dimensional hybrid manganese halides with the formula of AnMnX4 (A = organic cations, X = Cl, Br, n =1, 2) was synthesized through an economically and environmentally friendly mechanical grinding solid-state reaction within a quite fast time of 40 s and 100% yield. Even without any crystallization process, these AnMnX4 display strong green light emissions with the highest photoluminescence quantum yield (PLQY) of 79.5%, which reaches up to the top rank of green-light-emitting halide perovskites. Moreover, the enormous structural library facilitates us to build up a direct correlation between intermolecular Mn⋯Mn distances and PLQY, which provides a feasibility of fine-tuning luminescence performance by reasonably managing organic species to tailor the Mn⋯Mn distance. This work not only paves a green assembly way of hybrid perovskite materials but also provides a generalized method to rationally optimize the luminescence performances of hybrid manganese halides, which is potentially extended to all emissive hybrid metal halides. [ABSTRACT FROM AUTHOR]

Five new zero-dimensional hybrid manganese halides based on discrete [MnCl4]2− tetrahedrons were prepared and used as highly efficient green-light emitters. Through rational management of organic cations to tailor the Mn⋯Mn separation distances between neighboring [MnCl4]2− tetrahedrons, the photoluminescence quantum yield increased significantly from 7.98% to 81.11%. [ABSTRACT FROM AUTHOR]

One new type of hybrid lead halide of [DTHPE]2Pb3Cl10 has been synthesized and characterized containing a one-dimensional (1D) wavelike [Pb3Cl10]4− chain based on a corner-shared [Pb3Cl11] cluster. Remarkably, this cluster-based 1D chain displays intrinsic broadband white light emission with a high quantum efficiency of 19.45% exceeding those of previously reported typical two-dimensional perovskites. [ABSTRACT FROM AUTHOR]