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0.93(Bi 0.5− x /0.93 Er x /0.93 Na 0.5 )TiO 3 –0.07BaTiO 3 photoluminescent ceramics have been prepared by a conventional ceramic fabrication technique and their photoluminescence, ferroelectric, dielectric and piezoelectric properties have been studied. Under an excitation of 980 nm, the ceramics exhibit visible up-conversion luminescent emissions at 532 nm (green), 540 nm (green) and 600 nm (red), as well as broadband down-conversion luminescent emissions in near-infrared (1.44–1.66 μm) and mid-infrared (2.62–2.84 μm) regions. The quenching concentration for the ceramics is high, about 6%, and both the visible and invisible emissions are very strong. Among the emissions, the photoluminescence intensity of the red emission band increases most significantly by more than 47 times as the Er-concentration increases from 0.005 to 0.07. As a result, the Commission Internationale de L’Eclairage chromaticity coordinates shift from (0.29, 0.69) to (0.49, 0.50), and the emission color changes from green to yellowish green. Owing to the establishment of a dynamic circulatory energy process at high Er-concentrations, the photoluminescence intensity of the mid-infrared emission increases significantly by more than 4 times at the expense of the near-infrared emission. Together with the good ferroelectric and piezoelectric properties, the ceramics should be promising candidates for multifunctional optoelectronic applications. [ABSTRACT FROM AUTHOR]

The lead-free ceramics K0.5Na0.5NbO3 doped with x mol% Er3+ ions have been successfully manufactured and their photoluminescence properties, including the up-conversion visible (480-700 nm) emissions, down-conversion near infrared (1400-1680 nm) and middle infrared (2620-2850 nm) emissions, emission colors and lifetimes of the energy levels have been systemically investigated. The corresponding photoluminescence mechanism has been discussed in detail. Our results show that the Er-doping induces a phase transition from orthorhombic to cubic-like as well as inhibits the grain growth due to the donor-type nature. Both the change of crystallographic structures and concentration-quenching effect induced by Er3+ ions have great influences on the photoluminescence properties. Because of the wide emission ranges and long lifetimes, Er-doped K0.5Na0.5NbO3 ceramics are the promising candidates for optoelectronic applications. [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]

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]

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]

We demonstrate that the electroluminescent performances of organic light-emitting diodes (OLEDs) are significantly improved by evaporating a thin F4-TCNQ film as an anode buffer layer on the ITO anode. The optimum Alq3-based OLEDs with F4-TCNQ buffer layer exhibit a lower turn-on voltage of 2.6 V, a higher brightness of 39820 cd/m2 at 13 V, and a higher current efficiency of 5.96 cd/A at 6 V, which are obviously superior to those of the conventional device (turn-on voltage of 4.1 V, brightness of 18230 cd/m2 at 13 V, and maximum current efficiency of 2.74 cd/A at 10 V). Furthermore, the buffered devices with F4-TCNQ as the buffer layer could not only increase the efficiency but also simplify the fabrication process compared with the p-doped devices in which F4-TCNQ is doped into b-NPB as p-HTL (3.11 cd/A at 7V). The reason why the current efficiency of the p-doped devices is lower than that of the buffered devices is analyzed based on the concept of doping, the measurement of absorption and photoluminescence spectra of the organic materials, and the current density-voltage characteristics of the corresponding hole-only devices. [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]

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]

Recently, low-dimensional organic–inorganic hybrid metal halides have attracted considerable attention in solid-state optical application fields, especially in white-light emitting diodes (WLEDs) owing to intrinsic broadband luminescence performances. Herein, by selecting different types of organic cations as a structural decoration strategy, we designed a series of new 1D hybrid halides of A2Pb3Br10 (A = NPM, DMPDA, TMEN) based on same [Pb3Br10]4− chains composed of edge-shared [Pb3Br12]6− trimers. The low-dimensional crystal lattice results in the formation of self-trapped excitons, which leads to broadband light emissions covering the entire visible region for all A2Pb3Br10 homologues. Specifically, compound 1 exhibits yellowish-white light emission (0.34, 0.45) with a photoluminescence quantum efficiency of 2.51%. Both compounds 2 and 3 show bluish-white light emissions centered at 438 nm and 440 nm, respectively, with high color rendering index (CRI) of 96, which belongs to one of the highest values to date. The intrinsic broadband white light emissions enable them as promising candidates for single-component white-light emitting materials. [ABSTRACT FROM AUTHOR]

Considering the instability and low photoluminescence quantum yield (PLQY) of blue‐emitting perovskites, it is still challenging and attractive to construct single crystalline hybrid lead halides with highly stable and efficient blue light emission. Herein, by rationally introducing d10 transition metal into single lead halide as new structural building unit and optical emitting center, we prepared a bimetallic halide of [(NH4)2]CuPbBr5 with new type of three‐dimensional (3D) anionic framework. [(NH4)2]CuPbBr5 exhibits strong band‐edge blue emission (441 nm) with a high PLQY of 32 % upon excitation with UV light. Detailed photophysical studies indicate [(NH4)2]CuPbBr5 also displays broadband red light emissions derived from self‐trapped states. Furthermore, the 3D framework features high structural and optical stabilities at extreme environments during at least three years. To our best knowledge, this work represents the first 3D non‐perovskite bimetallic halide with highly efficient and stable blue light emission. [ABSTRACT FROM AUTHOR]

Considering the instability and low photoluminescence quantum yield (PLQY) of blue‐emitting perovskites, it is still challenging and attractive to construct single crystalline hybrid lead halides with highly stable and efficient blue light emission. Herein, by rationally introducing d10 transition metal into single lead halide as new structural building unit and optical emitting center, we prepared a bimetallic halide of [(NH4)2]CuPbBr5 with new type of three‐dimensional (3D) anionic framework. [(NH4)2]CuPbBr5 exhibits strong band‐edge blue emission (441 nm) with a high PLQY of 32 % upon excitation with UV light. Detailed photophysical studies indicate [(NH4)2]CuPbBr5 also displays broadband red light emissions derived from self‐trapped states. Furthermore, the 3D framework features high structural and optical stabilities at extreme environments during at least three years. To our best knowledge, this work represents the first 3D non‐perovskite bimetallic halide with highly efficient and stable blue light emission. [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]

Low-dimensional hybrid antimony halide perovskites have fascinated the extensive research for their excellent photoluminescence behaviors. However, reasonable optimization of luminescence performance through molecule-level structural regulation remains a formidable challenge. The solution evaporation method with the reaction of organic amines and acid solutions of metal salts is a well-established method for the synthetic of low-dimensional hybrid antimony halide. In this work, by selecting organic cations with different sizes as template molecules, we have successfully synthesized three hybrid antimony halides of 0D [HDBA] 2 SbCl 5 (1), 0D [H 2 ATMP] 2 SbCl 7 (2) and 1D [H 3 PMDETA]Sb 2 Cl 9 (3) (DBA ​= ​dibutylamine, ATMP ​= ​4-amino-2,2,6,6-tetramethylpiperidine, PMDETA = N,N,N′,N″,N″-pentamethyldiethylenetriamine). by the solution evaporation method at room temperature for 2–5 days. These hybrid antimony halides exhibit broadband yellow-light with the highest photoluminescence quantum yield (PLQY) of 8.38%. According to detailed spectroscopy characterizations and theoretical calculations, the broadband light emissions should originate from self-trapped excitons (STEs). These antimony halides could be fabricated as white LEDs with highest color rendering index (>90%). The intrinsic broad-band light emissions and facile assembly process enable these hybrid antimony halides as promising candidates for yellow-light emitting materials. Structural design of hybrid antimony halide : Three antimony chlorides with different structures were prepared by facile solution method. These antimony chlorides have 0D pyramidal [SbCl 5 ]2- and 1D [Sb 2 Cl 9 ]3- chains, and display the broadband yellow-light emissions. [Display omitted] • Lead-free hybrid antimony halides with 0D pyramidal [SbCl 5 ]2- and 1D [Sb 2 Cl 9 ]3- chains. • Broadband yellow-light emissions originate from self-trapped excitons. • These hybrid antimony halides can be fabricated as white LEDs with high CRI. [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]