Organic Metal Halide Hybrids Research Articles

Solution Processed Bilayer Metal Halide White Light Emitting Diodes.

Metal halide perovskites and perovskite-related organic metal halide hybrids (OMHHs) have recently emerged as a new class of luminescent materials for light emitting diodes (LEDs), owing to their unique and remarkable properties, including near-unity photoluminescence quantum efficiencies, highly tunable emission colors, and low temperature solution processing. While substantial progress has been made in developing monochromatic LEDs with electroluminescence across blue, green, red, and near-infrared regions, achieving highly efficient and stable white electroluminescence from a single LED remains a challenging and under-explored area. Here, a facile approach to generating white electroluminescence is reported by combining narrow sky-blue emission from metal halide perovskites and broadband orange/red emission from zero-dimensional (0D) OMHHs. For the proof of concept, utilizing TPPcarz+ passivated two-dimensional (2D) CsPbBr3 nanoplatelets (NPLs) as sky blue emitter and 0D TPPcarzSbBr4 as orange/red emitter (TPPcarz+ = triphenyl (9-phenyl-9H-carbazol-3-yl) phosphonium), white LEDs (WLEDs) with a solution processed bilayer structure have been fabricated to exhibit a peak external quantum efficiency (EQE) of 4.8% and luminance of 1507 cd m-2 at the Commission Internationale de L'Eclairage (CIE) coordinate of (0.32, 0.35). This work opens a new pathway for creating highly efficient and stable WLEDs using metal halide perovskites and related materials.

Identifying Practical DFT Functionals for Predicting 0D and 1D Organic Metal-Halide Hybrids

Identifying Practical DFT Functionals for Predicting 0D and 1D Organic Metal-Halide Hybrids

Antiferromagnetic Ordering in A One-Dimensional Organic Copper Chloride Hybrid Insulator.

Low dimensional (LD) organic metal halide hybrids (OMHHs) have recently emerged as new generation functional materials with exceptional structural and property tunability. Despite the remarkable advances in the development of LD OMHHs, optical properties have been the major functionality extensively investigated for most of LD OMHHs developed to date, while other properties, such as magnetic and electronic properties, remain significantly under-explored. Here, we report for the first time the characterization of the magnetic and electronic properties of a 1D OMHH, organic-copper (II) chloride hybrid (C8H22N2)Cu2Cl6. Owing to the antiferromagnetic coupling between Cu atoms through chloride bridges in 1D [Cu2Cl6 2-]∞ chains, (C8H22N2)Cu2Cl6 is found to exhibit antiferromagnetic ordering with a Néel temperature of 24 K. The two-terminal (2T) electrical measurement on a (C8H22N2)Cu2Cl6 single crystal reveals its insulating nature. This work shows the potential of LD OMHHs as a highly tunable quantum material platform for spintronics.

Antiferromagnetic Ordering in A One‐Dimensional Organic Copper Chloride Hybrid Insulator

AbstractLow dimensional (LD) organic metal halide hybrids (OMHHs) have recently emerged as new generation functional materials with exceptional structural and property tunability. Despite the remarkable advances in the development of LD OMHHs, optical properties have been the major functionality extensively investigated for most of LD OMHHs developed to date, while other properties, such as magnetic and electronic properties, remain significantly under‐explored. Here, we report for the first time the characterization of the magnetic and electronic properties of a 1D OMHH, organic‐copper (II) chloride hybrid (C8H22N2)Cu2Cl6. Owing to the antiferromagnetic coupling between Cu atoms through chloride bridges in 1D [Cu2Cl62−]∞ chains, (C8H22N2)Cu2Cl6 is found to exhibit antiferromagnetic ordering with a Néel temperature of 24 K. The two‐terminal (2T) electrical measurement on a (C8H22N2)Cu2Cl6 single crystal reveals its insulating nature. This work shows the potential of LD OMHHs as a highly tunable quantum material platform for spintronics.

Anomalous Charge Transfer from Organic Ligands to Metal Halides in Zero-Dimensional [(C6H5)4P]2SbCl5 Enabled by Pressure-Induced Lone Pair-πInteraction.

Low-dimensional (low-D) organic metal halide hybrids (OMHHs) have emerged as fascinating candidates for optoelectronics due to their integrated properties from both organic and inorganic components. However, for most of low-D OMHHs, especially the zero-D (0D) compounds, the inferior electronic coupling between organic ligands and inorganic metal halides prevents efficient charge transfer at the hybrid interfaces and thus limits their further tunability of optical and electronic properties. Here, using pressure to regulate the interfacial interactions, efficient charge transfer from organic ligands to metal halides is achieved, which leads to a near-unity photoluminescence quantum yield (PLQY) at around 6.0 GPa in a 0D OMHH, [(C6H5)4P]2SbCl5. In situ experimental characterizations and theoretical simulations reveal that the pressure-induced electronic coupling between the lone-pair electrons of Sb3+ and the π electrons of benzene ring (lp-π interaction) serves as an unexpected "bridge" for the charge transfer. Our work opens a versatile strategy for the new materials design by manipulating the lp-π interactions in organic-inorganic hybrid systems.

Anomalous Charge Transfer from Organic Ligands to Metal Halides in Zero‐Dimensional [(C6H5)4P]2SbCl5 Enabled by Pressure‐Induced Lone Pair‐π Interaction

AbstractLow‐dimensional (low‐D) organic metal halide hybrids (OMHHs) have emerged as fascinating candidates for optoelectronics due to their integrated properties from both organic and inorganic components. However, for most of low‐D OMHHs, especially the zero‐D (0D) compounds, the inferior electronic coupling between organic ligands and inorganic metal halides prevents efficient charge transfer at the hybrid interfaces and thus limits their further tunability of optical and electronic properties. Here, using pressure to regulate the interfacial interactions, efficient charge transfer from organic ligands to metal halides is achieved, which leads to a near‐unity photoluminescence quantum yield (PLQY) at around 6.0 GPa in a 0D OMHH, [(C6H5)4P]2SbCl5. In situ experimental characterizations and theoretical simulations reveal that the pressure‐induced electronic coupling between the lone‐pair electrons of Sb3+ and the π electrons of benzene ring (lp‐π interaction) serves as an unexpected “bridge” for the charge transfer. Our work opens a versatile strategy for the new materials design by manipulating the lp‐π interactions in organic–inorganic hybrid systems.

Efficient Red Light Emitting Diodes Based on a Zero‐Dimensional Organic Antimony Halide Hybrid (Adv. Mater. 9/2023)

Organic Metal Halide Hybrids Efficient electroluminescent devices can now be fabricated using solution-processed thin films based on 0D organic metal halide hybrids (OMHHs). In article number 2209417, Biwu Ma and co-workers develop a highly luminescent 0D OMHH containing organic semiconducting cations, which successfully addresses the issues of low conductivity and poor energy alignment of existing 0D OMHHs for electrically driven light-emitting diodes (LEDs).

Surface Effects on Anisotropic Photoluminescence in One‐Dimensional Organic Metal Halide Hybrids

1D organic metal halide hybrids (OMHHs) exhibit strongly anisotropic optical properties, highly efficient light emission, and large Stokes shift, holding promise for novel photodetection and lighting applications. However, the fundamental mechanisms governing their unique optical properties and in particular the impacts of surface effects are not understood. Herein, 1D C4N2H14PbBr4 by polarization‐dependent time‐averaged and time‐resolved photoluminescence (TRPL) spectroscopy, as a function of photoexcitation energy, is investigated. Surprisingly, it is found that the emission under photoexcitation polarized parallel to the 1D metal halide chains can be either stronger or weaker than that under perpendicular polarization, depending on the excitation energy. The excitation‐energy‐dependent anisotropic emission is attributed to fast surface recombination, supported by first‐principles calculations of optical absorption in this material. The fast surface recombination is directly confirmed by TRPL measurements, when the excitation is polarized parallel to the chains. The comprehensive studies provide a more complete picture for a deeper understanding of the optical anisotropy in 1D OMHHs.

Efficient Red Light Emitting Diodes Based on a Zero-Dimensional Organic Antimony Halide Hybrid.

Zero-dimensional (0D) organic metal halide hybrids (OMHHs) have recently emerged as a new class of light emitting materials with exceptional color tunability. While near-unity photoluminescence quantum efficiencies (PLQEs) are routinely obtained for a large number of 0D OMHHs, it remains challenging to apply them as emitter for electrically driven light emitting diodes (LEDs), largely due to the low conductivity of wide bandgap organic cations. Here, the development of a new OMHH, triphenyl(9-phenyl-9H-carbazol-3-yl) phosphonium antimony bromide (TPPcarzSbBr4 ), as emitter for efficient LEDs, which consists of semiconducting organic cations (TPPcarz+ ) and light emitting antimony bromide anions (Sb2 Br8 2- ), is reported. By replacing one of the phenyl groups in a well-known tetraphenylphosphonium cation (TPP+ ) with an electroactive phenylcarbazole group, a semiconducting TPPcarz+ cation is developed for the preparation of red emitting 0D TPPcarzSbBr4 single crystals with a high PLQE of 93.8%. With solution processed TPPcarzSbBr4 thin films (PLQE of 86.1%) as light emitting layer, red LEDs are fabricated to exhibit an external quantum efficiency (EQE) of 5.12%, a peak luminance of 5957cd m-2 , and a current efficiency of 14.2cd A-1 , which are the best values reported to date for electroluminescence devices based on 0D OMHHs.

Organic−Inorganic Manganese Bromide Hybrids with Water‐Triggered Luminescence for Rewritable Paper

AbstractStimuli‐responsive luminescent material‐based rewritable paper has received great attention for its potential application in a wide range of areas from anti‐counterfeiting to information encryption. Herein, a photoluminescence (PL) rewritable paper based on an organic metal halide, trans‐2,5‐dimethylpiperazine manganese(II) bromide (C6N2H16MnBr4) (1), is reported. This 0D organic metal halide hybrid exhibits green emission centered at 548 nm originating from 4T1–6A1 transition of tetrahedrally coordinated Mn2+ ions with a PL quantum efficiency of 82%. Interestingly, complex 1 can be transformed into the non‐emissive hydrated phase C6N2H16MnBr4(H2O)2 (2) by uptake of coordinating water molecules, wherein Mn2+ adopts a quasi‐octahedral coordination sphere. The reversible single‐crystal structure transformation between the hydrated and dehydrated phases can switch the PL on and off. Rewritable PL paper has been fabricated by coating complex 1 on filter paper, which exhibits high resolution and excellent “write‐erase‐write” cycle capability. This work presents a new avenue for low‐dimensional lead‐free organic metal halide hybrids toward multilevel information security applications.

Metal Halide Scaffolded Assemblies of Organic Molecules with Enhanced Emission and Room Temperature Phosphorescence.

Ionically bonded organic metal halide hybrids have emerged as versatile multicomponent material systems exhibiting unique and useful properties. The unlimited combinations of organic cations and metal halides lead to the tremendous structural diversity of this class of materials, which could unlock many undiscovered properties of both organic cations and metal halides. Here we report the synthesis and characterization of a series benzoquinolinium (BZQ) metal halides with a general formula (BZQ)Pb2X5 (X = Cl, Br), in which metal halides form a unique two-dimensional (2D) structure. These BZQ metal halides are found to exhibit enhanced photoluminescence and stability as compared to the pristine BZQ halides, due to the scaffolding effects of 2D metal halides. Optical characterizations and theoretical calculations reveal that BZQ+ cations are responsible for the emissions in these hybrid materials. Changing the halide from Cl to Br introduces heavy atom effects, resulting in yellow room temperature phosphorescence (RTP) from BZQ+ cations.

Low-Dimensional Organic Metal Halide Hybrids with Excitation-Dependent Optical Waveguides from Visible to Near-Infrared Emission.

Molecular luminescent materials with optical waveguide properties have wide application prospects in the fields of sensors, filters, and modulators. However, designing and synthesizing optical waveguide materials with unique morphology, high emissive efficiency, and tunable optical properties in the same solid-state system remains an open challenge. In this work, we report new types of morphological one-dimensional (1D) organic metal halide hybrid micro/nanotubes and micro/nanorods, which exhibit excitation-dependent optical waveguide properties from visible to near-infrared (NIR) regions with low-loss coefficient and high emissive efficiency during the propagation process. Strong intermolecular interactions within the hybrid systems could effectively reduce the nonradiative transition and improve quantum efficiency. Photophysical studies and theoretical calculations demonstrate that the color-tunable emission can be attributed to the coexistence of locally excited states and charge-transfer states. Utilizing excitation-dependent optical waveguide emission ranging from visible to NIR regions, we fabricate an optical wavelength converter to transfer short-wavelength into long-wavelength emission with multichannels. Furthermore, an optical logic gate system was designed based on the tunable emission properties of the 1D metal halide micro/nanotubes. Therefore, this work provides not only a facile process to synthesize 1D organic metal halide hybrids with excitation-dependent optical waveguide properties but also a new way to advance photofunctional logic computation at the micro/nanoscale.

Mechanochemical Synthesis of Zero Dimensional Organic‐Inorganic Metal Halide Hybrids

AbstractMechanochemical synthesis has emerged as a facile method for the preparation of a wide range of organic, inorganic, and polymeric materials. Here, we report the use of mechanochemical synthesis for the preparation of ionically bonded organic metal halide hybrids with a zero‐dimensional (0D) structure at the molecular level. (Ph4P)2SbCl5 and (Ph4P)2MnCl4 were synthesized by grinding appropriate ratios of organic halide salt Ph4PCl with inorganic metal halide salts SbCl3 and MnCl2, respectively. The structural and photophysical properties of mechanochemically synthesized (Ph4P)2SbCl5 and (Ph4P)2MnCl4 were characterized, which are almost identical to those of single crystals prepared by slow solution growth. By reacting Ph4PCl with both SbCl3 and MnCl2, we have been able to produce a mixture of two 0D organic metal halide hybrids that exhibit a dual emission covering a wide range of the spectrum with Commission Internationale de l'Eclairage (CIE) coordinates of (0.4898, 0.4800). Our work has clearly established mechanochemical synthesis as an effective method to produce ionically bonded organic‐inorganic hybrids.

Multicomponent Organic Metal Halide Hybrid with White Emissions

AbstractZero‐dimensional (0D) organic metal halide hybrids, in which organic and metal halide ions cocrystallize to form neutral species, are a promising platform for the development of multifunctional crystalline materials. Herein we report the design, synthesis, and characterization of a ternary 0D organic metal halide hybrid, (HMTA)4PbMn0.69Sn0.31Br8, in which the organic cation N‐benzylhexamethylenetetrammonium (HMTA+, C13H19N4+) cocrystallizes with PbBr42−, MnBr42−, and SnBr42−. The wide band gap of the organic cation and distinct optical characteristics of the three metal bromide anions enabled the single‐crystalline “host–guest” system to exhibit emissions from multiple “guest” metal halide species simultaneously. The combination of these emissions led to near‐perfect white emission with a photoluminescence quantum efficiency of around 73 %. Owing to distinct excitations of the three metal halide species, warm‐ to cool‐white emissions could be generated by controlling the excitation wavelength.

Semiconducting crystalline inorganic-organic hybrid metal halide nanochains.

One-dimensional (1D) inorganic-organic metal halide hybrids at the molecular level, which can be considered as arrays of nanochains isolated by organic components, have shown remarkable optical and electric properties. This review summarizes their reported structural types and shows how to modify their band gaps and optical and electric properties.

Microwave Absorption of Organic Metal Halide Nanotubes

AbstractOrganic metal halide hybrids have attracted tremendous research interests owing to their outstanding optical and electronic properties suitable for various applications, including photovoltaics, light‐emitting diodes, and photodetectors. Recently, the multifunctionality of this class of materials has been further explored beyond their optical and electronic properties. Here, for the first time the microwave electromagnetic properties of a 1D organic metal halide hybrid, (C6H13N4)3Pb2Br7, a single crystalline bulk assembly of organic metal halide nanotubes, are reported. Good microwave absorption performance with a large reflection loss value of −18.5 dB and a threshold bandwidth of 1.0 GHz is discovered for this material, suggesting its potential as a new microwave absorber. This work reveals a new functionality of organic metal halide hybrids and provides a new material class for microwave absorption application studies.

Bulk Assembly of Zero-Dimensional Organic Lead Bromide Hybrid with Efficient Blue Emission

Zero-dimensional (0D) organic metal halide hybrids are an emerging class of light emitting materials with exceptional photoluminescence quantum efficiencies (PLQEs), thanks to their perfect “host–g...

Green Emitting Single-Crystalline Bulk Assembly of Metal Halide Clusters with Near-Unity Photoluminescence Quantum Efficiency

Organic metal halide hybrids with zero-dimensional (0D) structure at the molecular level, or single-crystalline bulk assemblies of metal halides, are an emerging class of light-emitting materials w...

Organic Metal Halide Hybrids: Bulk Assembly of Corrugated 1D Metal Halides with Broadband Yellow Emission (Advanced Optical Materials 6/2019)

Organic Metal Halide Hybrids: Bulk Assembly of Corrugated 1D Metal Halides with Broadband Yellow Emission (Advanced Optical Materials 6/2019)

Bulk Assembly of Corrugated 1D Metal Halides with Broadband Yellow Emission

AbstractThe family of molecular level low‐dimensional organic metal halide hybrids has expanded significantly over the last few years. Here a new type of 1D metal halide structure is reported, in which metal halide octahedra form a corrugated double‐chain structure via nonplanar edge‐sharing. This material with a chemical formula of C5H16N2Pb2Br6 exhibits a broadband yellow emission under ultraviolet light excitation with a photoluminescence quantum efficiency of around 10%. The light‐yellow emission is considered to be attributed to self‐trapping excitons. Theoretical calculations show that the unique alignment of the octahedra leads to small band dispersion and large exciton binding energy. Together with previously reported 1D metal halide wires and tubes, this new bulk assembly of 1D metal halides suggests the potential to develop a library of bulk assemblies of metal halides with controlled structures and compositions.