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The glassy state of inorganic-organic hybrid metal halides combines their excellent optoelectronic properties with the outstanding processability of glass, showcasing unique application potential in solar devices, display technologies, and plastic electronics. Herein, by tailoring the organic cation from N -phenylpiperazine to dimethylamine gradually, four types of zero-dimensional antimony halides are obtained with various optical and thermal properties. The guest water molecules in crystal ( N -phenylpiperazine) 2 SbCl 6 ·Cl·5H 2 O lead to the largest distortion of the Sb-halogen unit, resulting in the red emission different from the yellow emission of other compounds. More importantly, the water molecule-induced hydrogen-bond network in ( N -phenylpiperazine) 2 SbCl 6 ·Cl·5H 2 O would prolong the relaxation time into an equilibrium state, resulting in the formation of the glassy state. This is different from the previous strategy of adopting large organic cations for glass transition. Through rheological studies, we shape an initial understanding of the underlying kinetics in inorganic-organic hybrid metal halide glass. This work provides a simpler and more convenient approach for developing inorganic-organic hybrid metal halides with superior processing performance.

The strategy of organic ligand exchange is proposed to tune the optical properties of organic-inorganic hybrid cuprous halides. In this work, the chiral ligand (S)-(-)-2,2'-bis(di- p -tolylphosphino)-1,1'-binaphthyl ((S)-Tol-BINAP) and achiral triphenylphosphine (PPh 3 ) are introduced into cuprous halides CuX-PPh 3 -[(S)-Tol-BINAP] (X = Cl, Br, I) through organic ligand exchange. As a result, the mixed organic ligands can enhance second harmonic generation (SHG) and aggregation-induced emission (AIE) optical properties. Moreover, the title compounds exhibit progressively enlarged SHG effects along with heavier halogen substitution due to their stronger polarizability. In the meantime, the reduced π-π stacking interaction of the organic ligand will improve their photoluminescence quantum yield. The experimental results combined with the theoretical calculation clarify the structure-property relationship well. Furthermore, the title compounds have been developed for the application of latent fingerprint detection.

Anisotropy is crucial for birefringence (Δn) in optical materials, but optimizing it remains a formidable challenge (Δn >0.3). Supramolecular frameworks incorporating π-conjugated components are promising for achieving enhanced birefringence because of their structural diversity and inherent anisotropy. Herein, we first synthesized (C 6 H 6 NO 2 ) + Cl - (NAC) and then constructed a halogen-bonded supramolecular framework I + (C 6 H 4 NO 2 ) - (INA) by halogen aliovalent substitution of Cl - with I + . The organic moieties are protonated and deprotonated nicotinic acid (NA), respectively. The antiparallel arrangement of birefringent-active units in NAC and INA leads to significant differences in the bonding characteristics between the interlayer and intralayer domains. Moreover, the [O⋅⋅⋅I + ⋅⋅⋅N] halogen bond in 1D [I + (C 6 H 4 NO 2 ) - ] chain exhibits stronger interactions and stricter directionality, resulting in a more pronounced in-plane anisotropy between the intrachain and interchain directions. Consequently, INA exhibits exceptional birefringent performance, with a value of 0.778 at 550 nm, twice that of NAC (0.363 at 550 nm). This value significantly exceeds those of commercial birefringent crystals, such as CaCO 3 (0.172 at 546 nm), and is the highest reported value among ultraviolet birefringent crystals. This work presents a novel design strategy that employs halogen bonds as connection sites and modes for birefringent-active units, opening new avenues for developing high-performance birefringent crystals., (© 2024 Wiley-VCH GmbH.)

Herein, the first F-containing iodate-phosphate, namely Ba 2 Ga 2 F 6 (IO 3 )(PO 4 ), was prepared via a hydrothermal reaction, in which HPF 6 (70 wt% solution in water) was used as the source of both fluoride and phosphate anions for the first time. Ba 2 Ga 2 F 6 (IO 3 )(PO 4 ) features an unprecedented 1D [Ga 2 F 6 (IO 3 )(PO 4 )] 4- helix chain, composed of a 1D Ga(1)(IO 3 )O 4 F chain via the bridging of 0D Ga(2)(PO 4 )F 5 . The UV-Vis spectrum shows that Ba 2 Ga 2 F 6 (IO 3 )(PO 4 ) has a wide bandgap with a short-UV absorption edge (4.35 eV; 253 nm). Birefringence measurement under a polarizing microscope shows that Ba 2 Ga 2 F 6 (IO 3 )(PO 4 ) displays a moderate birefringence of 0.072@550 nm, which is consistent with the value (0.070@550 nm) obtained by DFT calculations, indicating that Ba 2 Ga 2 F 6 (IO 3 )(PO 4 ) has potential applications as a short-UV birefringent material. This study highlights the crucial role played by the incorporation of specific functional groups into compounds, shedding light on their contribution to promising inorganic functional materials.

Using copper-ionophores to translocate extracellular copper into mitochondria is a clinically validated anticancer strategy that has been identified as a new type of regulated cell death termed "cuproptosis." This study reports a mitochondria-targeting Cu(I) complex, Cu(I)Br(PPh 3 ) 3 (CBP), consisting of a cuprous ion coordinated by three triphenylphosphine moieties and a Br atom. CBP exhibited antitumor and antimetastatic efficacy in vitro and in vivo by specifically targeting mitochondria instigating mitochondrial dysfunction. The cytotoxicity of CBP could only be reversed by a copper chelator rather than inhibitors of the known cell death, indicating copper-dependent cytotoxicity. Furthermore, CBP induced the oligomerization of lipoylated proteins and the loss of Fe-S cluster proteins, consistent with characteristic features of cuproptosis. Additionally, CBP induced remarkable intracellular generation of reactive oxygen species (ROS) through a Fenton-like reaction, indicating a complex antitumor mechanism. This is a proof-of-concept study exploiting the antitumor activity and mechanism of the Cu(I)-based mitochondria-targeting therapy.

van der Waals (vdW) superlattices, comprising different 2D materials aligned alternately by weak interlayer interactions, offer versatile structures for the fabrication of novel semiconductor devices. Despite their potential, the precise control of optoelectronic properties with interlayer interactions remains challenging. Here, we investigate the discrepancies between the SnS/TiS 2 superlattice (SnTiS 3 ) and its subsystems by comprehensive characterization and DFT calculations. The disappearance of certain Raman modes suggests that the interactions alter the SnS subsystem structure. Specifically, such structural changes transform the band structure from indirect to direct band gap, causing a strong PL emission (∼2.18 eV) in SnTiS 3 . In addition, the modulation of the optoelectronic properties ultimately leads to the unique phenomenon of thermally activated photoluminescence. This phenomenon is attributed to the inhibition of charge transfer induced by tunable intralayer strains. Our findings extend the understanding of the mechanism of interlayer interactions in van der Waals superlattices and provide insights into the design of high-temperature optoelectronic devices.

With the rapid development of white LEDs, the research of new and efficient white light emitting materials has attracted increasing attention. Zero dimensional (0D) organic-inorganic hybrid metal halide perovskites with superior luminescent property are promising candidates for LED application, due to their abundant and tailorable structure. Herein, [(CH 3 ) 3 S] 2 SnCl 6 ·H 2 O is synthesized as a host for dopant ions Bi 3+ and Sb 3+ . The Sb 3+ doped, or Bi 3+ /Sb 3+ co-doped, [(CH 3 ) 3 S] 2 SnCl 6 ·H 2 O has a tunable optical emission spectrum by means of varying dopant ratio and excitation wavelength. As a result, we can achieve single-phase materials suitable for emission ranging from cold white light to warm white light. The intrinsic mechanism is examined in this work, to clarify the dopant effect on the optical properties. The high stability of title crystalline material, against water, oxygen and heat, makes it promising for further application., (© 2024. The Author(s).)

Lead-based two-dimensional organic-inorganic hybrid perovskites (2D HOIPs) are popular materials with various optical properties, which can be tuned through metal ion doping. Due to the size and valence misfit, metal ion dopants in 2D lead-based HOIPs are still limited. In this work, Mn 2+ , Sb 3+ and Bi 3+ are doped into 2D (HDA) 2 PbBr 4 (HDA = protonated dopamine) successfully. As a result, the dopants in 2D (HDA) 2 PbBr 4 can induce their characteristic optical spectra, which is studied at different temperatures and excitation powers. The temperature-dependent energy transfer in the Mn-doped sample has been clarified, in which abnormal phenomena including negative thermal quenching have been observed. In addition, the dopant ions can impact the phase transition temperatures of the samples, especially lowering their crystallization temperatures greatly. The mussel-inspired organic cation, feasible metal ion regulation, and superior stability provide (HDA) 2 PbBr 4 potential for further applications.

Here, two isomeric ionic zero-dimensional indium bromide crystals of α ( 1 )/β ( 2 )-[OPy][InBr 4 (Phen)] (OPy = N -octylpyridinium; Phen = 1,10-phenanthroline) have been isolated simply by changing the cooling conditions in solvothermal syntheses. Structural comparisons indicate their different supramolecular interactions, which can be confirmed by Hirshfeld surface analyses. The crystal 2 has additional hydrogen bonds and π-π interactions; as a result, the more compact stacking of 2 could result in a 10-fold higher photoluminescence (PL) quantum yield (PLQY) than that of 1 . Density functional theory calculations confirm the electron transition from the inorganic moiety to the organic ligand, which provides a further understanding of the optical process. This work provides a new idea for designing PL indium-based halides by understanding the structure-PL relationship.

Metal ion-doped zero-dimensional halide perovskites provide good platforms to generate broadband emission and explore the fundamental dynamics of emission regulations. Recently, Sb 3+ -doped zero-dimensional halide perovskites have attracted considerable attention for the high quantum yield of yellow emission; however, the triplet state recombination is activated and the singlet state emission is usually absent. Herein, we fabricate an Sb 3+ -doped zero-dimensional [(CH 3 ) 4 N] 2 SnCl 6 perovskite that can induce singlet and triplet emission. Density functional theory calculation shows that there are some overlaps between the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals, which may induce a large energy separation between the lowest excited triplet states (T 1 ) and the lowest excited singlet states (S 1 ) [Δ E (S 1 - T 1 )], impeding all the carriers' transfer from the singlet state to the triplet state. As a result, the reserved singlet emission together with the triplet emission can be regulated by excitation wavelength in situ. In addition, different Bi 3+ ratios are co-doped into Sb 3+ @[(CH 3 ) 4 N] 2 SnCl 6 , resulting in a photoluminescence ex situ regulation. Single-phase white light LED and optical anti-counterfeiting are developed further.

Zero-dimensional organic-inorganic metal halide hybrids provide ideal bulk-crystal platforms for exploring the pressure engineering of electron-phonon coupling (EPC) and self-trapped exciton (STE) emission at the molecular level. However, the low stiffness of inorganic clusters hinders the reversible tuning of these physical properties. Herein, we designed a Sb 3+ -doped metal halide with a high emission yield (89.4%) and high bulk modulus (35 GPa) that enables reversible and enhanced STE emission (20-fold) under pressure. The high lattice rigidity originates from the corner-shared cage-structured inorganic tetramers and ring-shaped organic ligands. Further, we reveal that the pressure-enhanced emission regime below 4.5 GPa is owing to the lattice hardening and preferably EPC strength reducing, while the pressure-insensitive emission regime within 4.5-8.5 GPa results from the enhanced intercluster Coulombic attraction force that resists intracluster compression. These results provide insights into the structure-property relation and molecular engineering of zero-dimensional metal halides toward wide-band and pressure-sensitive light sources.

In this study, we identify a novel class of second-order nonlinear optical (NLO) crystals, non-π-conjugated piperazine (H 10 C 4 N 2 , PIP) metal halides, represented by two centimeter-sized, noncentrosymmetric organic-inorganic metal halides (OIMHs), namely H 12 C 4 N 2 CdI 4 ( P 2 1 2 1 2 1 ) and H 11 C 4 N 2 CdI 3 ( Cc ). H 12 C 4 N 2 CdI 4 is the first to be prepared, and its structure contains a CdI 4 tetrahedron, which led to a poor NLO performance, including a weak and non-phase-matchable second harmonic generation (SHG) response of 0.5 × KH 2 PO 4 (KDP), a small birefringence of 0.047 @1064 nm and a narrow bandgap of 3.86 eV. Moreover, H 12 C 4 N 2 CdI 4 is regarded as the model compound, and we further obtain H 11 C 4 N 2 CdI 3 via the replacement of CdI 4 with a highly polarizable CdNI 3 tetrahedron, which results in a sharp enhancement of SHG response and birefringence. H 11 C 4 N 2 CdI 3 exhibits a promising NLO performance including 6 × KDP, 4.10 eV, Δ n = 0.074 @1064 nm and phase matchability, indicating that it is the first OIMH to simultaneously exhibit strong SHG response (>5 × KDP) and a wide bandgap (>4.0 eV). Our work presents a novel direction for designing high-performance NLO crystals based on organic-inorganic halides and provides important insights into the role of the hybridized tetrahedron in enhancing the SHG response and birefringence., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Bismuth-halide-based inorganic-organic hybrid materials (Bi-IOHMs) are desirable in luminescence-related applications due to their advantages such as low toxicity and chemical stability. Herein, two Bi-IOHMs of [Bpy][BiCl 4 (Phen)] ( 1 , Bpy = N -butylpyridinium, Phen = 1,10-phenanthroline) and [PP14][BiCl 4 (Phen)]·0.25H 2 O ( 2 , PP14 = N -butyl- N -methylpiperidinium), containing different ionic liquid cations and same anionic units, have been synthesized and characterized. Single-crystal X-ray diffraction reveals that compounds 1 and 2 crystallize in the monoclinic space group of P 2 1 / c and P 2 1 , respectively. They both possess zero-dimensional ionic structures and exhibit phosphorescence at room temperature upon excitation of UV light (375 nm for 1 , 390 nm for 2 ), with microsecond lifetime (24.13 μs for 1 and 95.37 μs for 2 ). Hirshfeld surface analysis has been utilized to visually exhibit the different packing motifs and intermolecular interactions in 1 and 2 . The variation in ionic liquids makes compound 2 have a more rigid supramolecular structure than 1 , resulting in a significant enhancement in photoluminescence quantum yield (PLQY), that is, 0.68% for 1 and 33.24% for 2 . In addition, the ratio of the emission intensities for compounds 1 and 2 shows a correlation with temperature. This work provides new insight into luminescence enhancement and temperature sensing applications involving Bi-IOHMs.

Intricate superstructures possess unusual structural features and promising applications. The preparation of superstructures with single-crystalline nature are conducive to understanding the structure-property relationship, however, remains an intriguing challenge. Herein we put forward a new hierarchical assembly strategy towards rational and precise construction of intricate single-crystal superstructures. Firstly, two unprecedented superclusters in Rubik's cube's form with a size of ≈2×2×2 nm 3 are constructed by aggregation of eight {Pr 4 Sb 12 } oxohalide clusters as secondary building units (SBUs). Then, the Rubik's cubes further act as isolable tertiary building units (TBUs) to assemble diversified single-crystal superstructures. Importantly, intermediate assembly states are captured, which helps illustrate the evolution of TBU-based superstructures and thus provides a profound understanding of the assembly process of superstructures at the atomic level., (© 2023 Wiley-VCH GmbH.)

Recently zero-dimensional (0-D) inorganic-organic metal halides (IOMHs) have become a promising class of optoelectronic materials. Herein, we report a new photoluminescent (PL) 0-D antimony(III)-based IOMH single crystal, namely [H 2 BPZ][SbCl 5 ]·H 2 O (BPZ = benzylpiperazine). Photophysical characterizations indicate that [H 2 BPZ][SbCl 5 ]·H 2 O exhibits singlet/triplet dual-band emission. Density functional theory (DFT) calculations suggest that [H 2 BPZ][SbCl 5 ]·H 2 O has the large energy difference between singlet and triplet states, which might induce the dual emission in this compound. Temperature-dependent PL spectra analyses suggest the soft lattice and strong electron-phonon coupling in this compound. Thermogravimetric analysis shows that the water molecules in the lattice of the title crystal could be removed by thermal treatment, giving rise to a dehydrated phase of [H 2 BPZ][SbCl 5 ]. Interestingly, such structural transformation is accompanied by a reversible PL emission transition between red light (630 nm, dehydrated phase) and yellow light (595 nm, water-containing phase). When being exposed to an environment with 77% relative humidity, the emission color of the dehydrated phase was able to change from red to yellow within 20 s, and the red emission could be restored after reheating. The red to yellow emission switching could be achieved in acetone with water concentration as low as 0.2 vol%. The reversible PL transition phenomenon makes [H 2 BPZ][SbCl 5 ]·H 2 O a potential material for luminescent water-sensing.

Polydopamine (PDA) is a good adhesion agent for lots of gels inspired by the mussel, whereas hybrid organic-inorganic perovskites (HOIPs) usually exhibit extraordinary optoelectronic performance. Herein, mussel-inspired chemistry has been integrated with two-dimensional HOIPs first, leading to the preparation of new crystal (HDA) 2 PbBr 4 ( 1 ) (DA = dopamine). The organic cation dopamine can be introduced into PDA resulting in a thin film of (HPDA) 2 PbBr 4 ( PDA-1 ). The dissolved inorganic components of layered perovskite in DMF solution together with H 2 O 2 addition can facilitate DA polymerization greatly. More importantly, PDA-1 can inherit an excellent semiconductor property of HOIPs and robust adhesion of the PDA hydrogel resulting in a self-adhesive photoelectric coating on various interfaces.

Herein, two novel metal iodate-fluorides, ZrF 2 (IO 3 ) 2 and RbGaF 3 (IO 3 ), have been prepared via hydrothermal reactions. In the structure of ZrF 2 (IO 3 ) 2 , neighboring Zr atoms are connected via a pair of F atoms into the one-dimensional (1D) [ZrF 2 ] 2+ cationic chain, which further attaches two iodate groups forming 1D ZrF 2 (IO 3 ) 2 , whereas the 1D cationic chain in RbGaF 3 (IO 3 ) is [GaF] 2+ , formatted by the bridging of Ga 3+ cations and axial F - anions, which further connect with one iodate group and two terminal F - anions into 1D [GaF 3 (IO 3 )] - anionic chains. According to the experimental characterization and theoretical calculations, both of them exhibit wide bandgaps (4.24 and 4.61 eV), short absorption edges (242 and 216 nm), and large birefringence (Δ n cal = 0.329 @1064 nm and Δ n cal = 0.174 @1064 nm for ZrF 2 (IO 3 ) 2 and RbGaF 3 (IO 3 ), respectively), indicating that they can be candidates as UV birefringent materials.

Zero-dimensional (0D) organic-inorganic metal halides (OIMHs) hold promise in photoluminescence properties and related applications. Thus far, the photoluminescence quantum yields (PLQYs) of the reported 0D hybrid antimony(III) bromides (HABs) are not as high as those of the chloride analogs; therefore, the improvement of PLQY is an important issue for luminescent HABs. Herein, a supramolecular interaction adjustment strategy to improve the PLQYs of HABs is proposed. Two isostructural 0D HABs that crystallize with different lattice solvent molecules, namely [EtPPh 3 ] 2 [SbBr 5 ]·EtOH (1·EtOH-Br; EtPPh 3 = ethyltriphenylphosphonium; EtOH = ethanol) and [EtPPh 3 ] 2 [SbBr 5 ]·MeCN (1·MeCN-Br; MeCN = acetonitrile), have been synthesized. Both of them exhibit typical self-trapped exciton (STE) photoluminescence (PL) with broad emission, a large Stokes shift and a long lifetime. They show deviation in deep-red emission peaks (655 nm vs. 661 nm) owing to the difference in the distortion level of [SbBr 5 ] 2- anions. Most importantly, 1·EtOH-Br exhibits a nearly one-fold enhancement in PLQY compared to 1·MeCN-Br (18.26% vs. 9.29%). Density functional theory (DFT) calculations, hydrogen bonding analysis and Hirshfeld surface analysis suggest that the PLQY enhancement is due to the structural rigidity improvement brought by hydrogen bonding adjustments between the inorganic [SbBr 5 ] 2- anions and solvent molecules. This work provides a new insight into the structure-property relationship study and PLQY improvement for 0D OIMHs.

A promising anode material consisting of bimetallic thiophosphate Zn x Co 1- x PS 3 and CoS 2 with 2D/3D heterostructure is designed and prepared by an effective chemical transformation. Density functional theory calculations illustrate that the Zn 2+ can effectively modulate the electrical ordering of Zn x Co 1- x PS 3 on the nanoscale: the reduced charge distribution emerging around the Zn ions can enhance the local built-in electric field, which will accelerate the ions migration rate by Coulomb forces and provide tempting opportunities for manipulating Li + storage behavior. Moreover, the merits of the large planar size enable Zn x Co 1- x PS 3 to provide abundant anchoring sites for metallic CoS 2 nanocubes, generating a 2D/3D heterostructure with a strong electric field. The resultant Zn x Co 1- x PS 3 /CoS 2 can offer the combined advantages of bimetallic alloying and heterostructure in lithium storage applications, leading to outstanding performance as an anode material for lithium-ion batteries. Consequently, a high capacity of 794 mA h g -1 can be retained after 100 cycles at 0.2 A g -1 . Even at 3.0 A g -1 , a satisfactory capacity of 465 mA h g -1 can be delivered. The appealing alloying-heterostructure and electrochemical performance of this bimetallic thiophosphate demonstrate its great promise for applications in practical rechargeable batteries., (© 2021 Wiley-VCH GmbH.)

Compound [C 5 mim][Mim] 2 [SbCl 6 ] (1; [C 5 mim] + = 1-pentyl-3-methylimidazolium; [Mim] + = N -methylimidazolium) with dual cations exhibits the first case of deep-red emission in [SbCl 6 ] 3- -based 0D OIMHs. Anion distortion due to high disequilibrium of supramolecular interactions is revealed to be responsible for the extremely large Stokes shift of 335 nm and FWHM of 210 nm in the emission.

Zero-dimensional (0D) metal halides with solid-state luminescence switching (SSLS) have attracted attention as sensors and luminescent anticounterfeiting. Herein, selective solvent molecule response and accordingly luminescence switching were discovered in 0D [EtPPh 3 ] 2 [SbCl 5 ] ( 1 , EtPPh 3 = ethyltriphenylphosphonium). More than a dozen kinds of solvent molecules have been tested to find out the selection rule for molecule absorption in 1 , which is demonstrated to be the size effect of guest molecules. Confirmed by crystal structural analysis, only the solvents with molecular volume less than 22.3 Å 3 could be accommodated in 1 leading to the solvatochromic photoluminescence (PL). The mechanism of solvatochromic PL was also deeply studied, which was found to be closely related to the supramolecular interactions between solvent molecules and the host material. Different functional groups of the solvent molecule can affect its strength of hydrogen bonding with [SbCl 5 ] 2- , which is crucial for the distortion level of [SbCl 5 ] 2- unit and thus results in not only distinct solvatochromic PL but also distinct thermochromic PL. In addition, they all show typical self-trapped exciton triplet emissions. The additional supramolecular interactions from guest molecules can enhance the photoluminescence quantum yield to be as high as 95%.

Although luminescent indium(III) based halide perovskites have been widely investigated, the study of emissive indium(III) halide hybrids is limited. Three indium(III) chloride hybrids based on a bpym ligand were synthesized, namely [EPy] 2 [InCl 4 (bpym)InCl 4 ]·DMF (1), [EPy] 2 [InCl 4 (bpym)InCl 4 ] (2), and [BPy] 2 [InCl 4 (bpym)InCl 4 ] (3) (EPy = N -ethylpyridinium; BPy = N -butylpyridinium; bpym = 2,2'-bipyrimidine). They all exhibit a zero-dimensional structure, in which the ligand bpym interconnects two [InCl 4 ] - to form a [InCl 4 (bpym)InCl 4 ] 2- anion that is further charge-compensated by the corresponding pyridinium cations. This is the first time using bpym to coordinate with an In atom. At 298 K, 1 exhibits a weak emission at 600 nm while 2 and 3 exhibit emissions peaking at 500 nm and 540 nm, respectively. Interestingly, the DMF solvent molecule in 1 can be removed by heating, thus resulting in the structural transformation of 1 into 2 together with a photoluminescence (PL) change. Density functional theory (DFT) calculations confirm that halogen-to-ligand charge-transfer (HLCT) occurs in the emission process. To the best of our knowledge, this is the first report on PL of ionic indium(III) halide hybrids incorporating organic ligands.

Bi 3+ /Te 4+ co-doped Cs 2 SnCl 6 with dual emission spectrum (i.e., 450 and 575 nm) was achieved by a modified solution method, which can overcome the phase separation in the previous method for Cs 2 SnCl 6 crystal growth. The two emission peaks arising from the two dopants Bi 3+ and Te 4+ have distinct photoluminescence (PL) lifetimes. Thus, the control of dopant ratio or PL delay time will regulate the PL intensity ratio between 450 and 575 nm peaks leading to adjustable emission color. The energy transfer between the two emission centers, which is confirmed by the optical spectra and PL lifetime, has a critical distance around 7.8 nm with a maximum of 50% transfer efficiency. The Bi 3+ /Te 4+ co-doped Cs 2 SnCl 6 with superior stability in water and aqua regia was fabricated into a single-phase white light-emitting diode. In the meantime, various luminescent heterostructures were obtained by epitaxial Cs 2 SnCl 6 crystal growth with different dopants, which can broaden the study of composition engineering in halide perovskites.

The exploration of advanced anode materials through rational structure/phase design is the key to developing high-performance rechargeable batteries. Herein, tetraphosphorus tetraselenide (Se 4 P 4 ) nanoparticles confined within porous carbon (named SeP@C) are developed for lithium-ion batteries. The designed SeP@C shows a set of structural/compositional advantages as lithium-ion battery anodes including high electrical conductivity, low ion diffusion barrier, and relieved lithiation stress. Consequently, the SeP@C electrode displays superior comprehensive lithium storage performance, e.g., high reversible capacity (640.8 mA h g -1 at 0.1 A g -1 ), excellent cycling stability (500 cycles with respective capacity retention of over or nearly 100%), and good rate capability, representing a comparable lithium storage performance in reported phosphide-based anodes. More significantly, it shows excellent energy storage properties in lithium-ion full cells which can light up 85 red LEDs for over 3.2 h. This work offers an advanced electrode construction guidance of phosphorous-based anodes for the development of high-performance energy storage devices., (© 2021 IOP Publishing Ltd.)

Zero-dimensional (0D) organic-inorganic hybrid metal halides (OIMHs) containing multiple halometallate species (HMSs) have received extensive attention due to their capability to achieve multifunctional photophysical characteristics. Herein we report a lead-free 0D-OIMH compound, namely [Emim]8[SbCl6]2[SbCl5] (1, Emim = 1-ethyl-3-methylimidazolium), which is the first crystal containing two distinct mononuclear [SbXn]3-n units in one single structure. The optical absorption, temperature/excitation-variable photoluminescence (PL) and PL decay were studied. 1 exhibits a broad emission centered at 577 nm, which is analyzed to be a combination of the emissions from [SbCl6]3- and [SbCl5]2-. The structural effects including SbSb distances and polyhedral distortion of [SbXn]3-n on the PL of antimony-based 0D-OIMHs are discussed in detail. This work would provide guidance for constructing Sb-based 0D OIMHs composed of multiple halometallate species.

CsMnCl3(H2O)2 (CMCH) has been widely investigated for magnetic and optical applications, including anti-Stokes photoluminescence, microwave absorption, and magnon-assisted optical transitions. Herein, CMCH crystals, which are colorless and transparent (unlike the pink crystals reported previously), were obtained through a unique approach. Consequently, a high-resolution optical absorption spectrum and distinct thermal behavior were observed. The reversible (de)hydration of CMCH being accompanied by photoluminescence switching (mainly in terms of the color temperature) was rationalized using crystal structure analysis. As a result, water-soluble CMCH could be applied as a moisture-responsive luminescent ink. Moreover, density functional theory (DFT) calculations were performed to understand the optical absorption of CMCH.

Two bismuth(III) halides hybrids with room-temperature phosphorescence (RTP), namely, [BPy] 2 [Bi 2 Cl 8 (bpym)] ( 1 , BPy = N -butylpyridinium) and [EPy] 2 [Bi 2 Cl 8 (bpym)] ( 2 , EPy = N -ethylpyridinium), were synthesized and characterized. Structural comparison reveals that 1 and 2 possess similar anionic zigzaglike chain of [Bi 2 Cl 8 (bpym)] n 2 n - ; however, different packing modes of anion/cations and thus different weak interactions. Interestingly, the utilization of pyridinium cations with different length of alkyl chain could tune the RTP behaviors efficiently. The RTP quantum yield (QY) is increased more than 5-fold from 1 to 2 probably due to more rigid structure of 2 arising from the additional H-bond and anion-π interactions, as confirmed by Hirshfeld surfaces analyses and PLATON calculations. Moreover, additional π-π interactions in 1 could stabilize the triplet excitons, leading to an average lifetime of 1 (11.36 ms at 77 K and 1.407 ms at 298 K) being higher than 2 (0.3618 ms at 77 K and 0.07511 ms at 298 K). Density functional theory (DFT) calculations confirm that inorganic moiety to organic ligand charge-transfer (IOCT) is involved in the phosphorescence process. The present work provides a new sight into the design of RTP metal halides through studying the structure-RTP relationship.

Phonon-assisted single-photon upconversion, which was not previously reported in organic materials, has been demonstrated in the 6-pentaceneone crystal through the linear pumping power dependent anti-Stokes photoluminescence (ASPL), nanoseconds PL lifetime and quenched ASPL at low temperature. Furthermore, the 6-pentaceneone crystal can be mechanically exfoliated to ultrathin flakes and it exhibits thickness-dependent photoluminescence.

The discovery of new halide perovskite-type structures could favor the exploration of optoelectronic materials, as in the case of double perovskites applied in solar cells, light-emitting diodes, and X-ray detectors. In this work, we propose a strategy for designing quadruple perovskites by heterovalent cation transmutation from double perovskites. Two stable quadruple perovskite halides, i.e., Cs 4 CdSb 2 Cl 12 and Cs 4 CdBi 2 Cl 12 , with a vacancy-ordered three-dimensional (3D) crystal structure were predicted through symmetry analysis and density functional theory (DFT) calculations. The title perovskite halides are also electronically 3D with direct forbidden bandgaps. Following the indication provided by the DFT results, Cs 4 CdSb 2 Cl 12 and Cs 4 CdBi 2 Cl 12 as unique quadruple perovskites were successfully synthesized by a solvothermal method. The steady-state photoluminescence (PL) shows wide emission, while the transient PL exhibits carrier recombination lifetime on the order of microseconds at low temperature. The quadruple perovskite halides provide an alternative platform for promising optoelectronic material design in addition to simple and double perovskites.

The different hydrogen bond interactions in two organic-inorganic hybrid manganese halide compounds, namely [A]2[MnBr4] (A = N-butyl-N-methylpyrrolidinium ([P14]+) for (1) and N-butyl-N-methylpiperidinium ([PP14]+) for (2)), lead to distinct photoluminescence quantum yields (81% for 1; 55% for 2). Further applications of luminescent 1 are also developed.

Differences in the electronegativity and hydrophilicity of halogens lead to differences in proton-conducting and photoluminescence properties in hybrid organic-inorganic lead halide compounds of [PbX 2 (OOCMMIm)] n (X = Cl (1), Br (2), HOOCMMIm = 1-carboxymethyl-3-methylimidazolium).

For a class of 2D hybrid organic-inorganic perovskite semiconductors based on π-conjugated organic cations, we predict quantitatively how varying the organic and inorganic component allows control over the nature, energy, and localization of carrier states in a quantum-well-like fashion. Our first-principles predictions, based on large-scale hybrid density-functional theory with spin-orbit coupling, show that the interface between the organic and inorganic parts within a single hybrid can be modulated systematically, enabling us to select between different type-I and type-II energy level alignments. Energy levels, recombination properties, and transport behavior of electrons and holes thus become tunable by choosing specific organic functionalizations and juxtaposing them with suitable inorganic components.

Recently, Cu I - and Ag I -based halide double perovskites have been proposed as promising candidates for overcoming the toxicity and instability issues inherent within the emerging Pb-based halide perovskite absorbers. However, up to date, only Ag I -based halide double perovskites have been experimentally synthesized; there are no reports on successful synthesis of Cu I -based analogues. Here we show that, owing to the much higher energy level for the Cu 3d 10 orbitals than for the Ag 4d 10 orbitals, Cu I atoms energetically favor 4-fold coordination, forming [CuX 4 ] tetrahedra (X=halogen), but not 6-fold coordination as required for [CuX 6 ] octahedra. In contrast, Ag I atoms can have both 6- and 4-fold coordinations. Our density functional theory calculations reveal that the synthesis of Cu I halide double perovskites may instead lead to non-perovskites containing [CuX 4 ] tetrahedra, as confirmed by our material synthesis efforts., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A series of two-dimensional (2D) hybrid organic-inorganic perovskite (HOIP) crystals, based on acene alkylamine cations (i.e., phenylmethylammonium (PMA), 2-phenylethylammonium (PEA), 1-(2-naphthyl)methanammonium (NMA), and 2-(2-naphthyl)ethanammonium (NEA)) and lead(II) halide (i.e., PbX 4 2- , X = Cl, Br, and I) frameworks, and their corresponding thin films were fabricated and examined for structure-property relationship. Several new or redetermined crystal structures are reported, including those for (NEA) 2 PbI 4 , (NEA) 2 PbBr 4 , (NMA) 2 PbBr 4 , (PMA) 2 PbBr 4 , and (PEA) 2 PbI 4 . Non-centrosymmetric structures from among these 2D HOIPs were confirmed by piezoresponse force microscopy-especially noteworthy is the structure of (PMA) 2 PbBr 4 , which was previously reported as centrosymmetric. Examination of the impact of organic cation and inorganic layer choice on the exciton absorption/emission properties, among the set of compounds considered, reveals that perovskite layer distortion (i.e., Pb-I-Pb bond angle between adjacent PbI 6 octahedra) has a more global effect on the exciton properties than octahedral distortion (i.e., variation of I-Pb-I bond angles and discrepancy among Pb-I bond lengths within each PbI 6 octahedron). In addition to the characteristic sharp exciton emission for each perovskite, (PMA) 2 PbCl 4 , (PEA) 2 PbCl 4 , (NMA) 2 PbCl 4 , and (PMA) 2 PbBr 4 exhibit separate, broad "white" emission in the long wavelength range. Piezoelectric compounds identified from these 2D HOIPs may be considered for future piezoresponse-type energy or electronic applications.

The double perovskite family, A 2 M I M III X 6 , is a promising route to overcome the lead toxicity issue confronting the current photovoltaic (PV) standout, CH 3 NH 3 PbI 3 . Given the generally large indirect band gap within most known double perovskites, band-gap engineering provides an important approach for targeting outstanding PV performance within this family. Using Cs 2 AgBiBr 6 as host, band-gap engineering through alloying of In III /Sb III has been demonstrated in the current work. Cs 2 Ag(Bi 1-x M x )Br 6 (M=In, Sb) accommodates up to 75 % In III with increased band gap, and up to 37.5 % Sb III with reduced band gap; that is, enabling ca. 0.41 eV band gap modulation through introduction of the two metals, with smallest value of 1.86 eV for Cs 2 Ag(Bi 0.625 Sb 0.375 )Br 6 . Band structure calculations indicate that opposite band gap shift directions associated with Sb/In substitution arise from different atomic configurations for these atoms. Associated photoluminescence and environmental stability of the three-metal systems are also assessed., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Recently, there has been substantial interest in developing double-B-cation halide perovskites, which hold the potential to overcome the toxicity and instability issues inherent within emerging lead halide-based solar absorber materials. Among all double perovskites investigated, In(I)-based Cs 2 InBiCl 6 and Cs 2 InSbCl 6 have been proposed as promising thin-film photovoltaic absorber candidates, with computational examination predicting suitable materials properties, including direct bandgap and small effective masses for both electrons and holes. In this study, we report the intrinsic instability of Cs 2 In(I)M(III)X 6 (M = Bi, Sb; X = halogen) double perovskites by a combination of density functional theory and experimental study. Our results suggest that the In(I)-based double perovskites are unstable against oxidation into In(III)-based compounds. Further, the results show the need to consider reduction-oxidation (redox) chemistry when predicting stability of new prospective electronic materials, especially when less common oxidation states are involved.

Exploring new ion-exchangers for the recovery of rare earth elements (REEs) and recycling is worthwhile for the high-tech industry and an eco-friendly sustainable economy. The efficient enrichment of low concentration REE from complex aqueous solutions containing large excess of competitive ions is challenging. Here we present a chalcogenide example as a superior REE ion-exchanger efficiently removing them from very complex aqueous solutions, (Me 2 NH 2 ) 1.33 (Me 3 NH) 0.67 Sn 3 S 7 ·1.25H 2 O (FJSM-SnS). The material exhibits fast and efficient ion exchange behavior with short equilibrium time (<5 min), high adsorption capacity (139 mg/g for Eu, 147 mg/g for Tb, 126 mg/g for Nd), wide pH resistance (1.9-8.5), the largest distribution coefficient (K d ) value of 6.5 × 10 6 mL/g, good selectivity against Al 3+ , Fe 3+ , and Na + ions, and high recovery rate (>99%) at low concentrations. Moreover, after ion-exchange, the REE in corresponding exchanged products could be easily recovered by elution. FJSM-SnS has superior capacity and faster absorption kinetics than other states of the artificial REE sorbents such as Al 2 O 3 /EG, clay minerals, zeolite, and activated carbon.

Uranium is important in the nuclear fuel cycle both as an energy source and as radioactive waste. It is of vital importance to recover uranium from nuclear waste solutions for further treatment and disposal. Herein we present the first chalcogenide example, (Me2NH2)1.33(Me3NH)0.67Sn3S7·1.25H2O (FJSM-SnS), in which organic amine cations can be used for selective UO2(2+) ion-exchange. The UO2(2+)-exchange kinetics perfectly conforms to pseudo-second-order reaction, which is observed for the first time in a chalcogenide ion-exchanger. This reveals the chemical adsorption process and its ion-exchange mechanism. FJSM-SnS has excellent pH stability in both strongly acidic and basic environments (pH = 2.1-11), with a maximum uranium-exchange capacity of 338.43 mg/g. It can efficiently capture UO2(2+) ions in the presence of high concentrations of Na(+), Ca(2+), or HCO3(-) (the highest distribution coefficient Kd value reached 4.28 × 10(4) mL/g). The material is also very effective in removing of trace levels of U in the presence of excess Na(+) (the relative amounts of U removed are close to 100%). The UO2(2+)···S(2-) interactions are the basis for the high selectivity. Importantly, the uranyl ion in the exchanged products could be easily eluted with an environmentally friendly method, by treating the UO2(2+)-laden materials with a concentrated KCl solution. These advantages coupled with the very high loading capacity, low cost, environmentally friendly nature, and facile synthesis make FJSM-SnS a new promising remediation material for removal of radioactive U from nuclear waste solutions.

A new chalcogenide crystal, (NH4)4Ag12Sn7Se22 (FJSM-STS), has been solvothermally synthesized. The crystal structure, which is composed of arrays of [Sn3Se9]n(6n-) chains interconnecting [SnAg6Se10]n(10n-) and [Ag3Se4]n(5n-) layers, is unprecedented among the reported A/Ag/Sn/Q (A = cation; Q = S, Se, and Te) compounds. Optical absorption together with theoretical calculations of the band structure indicate a direct band gap of 1.21 eV for FJSM-STS, which is close to the ideal band gap to maximize the photoconversion efficiency proposed by Shockley and Queisser. The toxic-metal-free crystal of FJSM-STS exhibits obvious photosensitivity in the near-infrared range. The variates of power and temperature on the photosensitivity have been studied.

2D semiconducting metal phosphorus trichalcogenides, particularly the bulk crystals of MPS3 (M = Fe, Mn, Ni, Cd and Zn) sulfides and MPSe3 (M = Fe and Mn) selenides, have been synthesized, crystallized and exfoliated into monolayers. The Raman spectra of monolayer FePS3 and 3-layer FePSe3 show the strong intralayer vibrations and structural stability of the atomically thin layers under ambient condition. The band gaps can be adjusted by element choices in the range of 1.3-3.5 eV. The wide-range band gaps suggest their optoelectronic applications in a broad wavelength range. The calculated cleavage energies of MPS3 are smaller than that of graphite. Therefore, the monolayers used for building of heterostructures by van der Waals stacking could be considered as the candidates for artificial 2D materials with unusual ferroelectric and magnetic properties.

CdS synthesis by plasma-enhanced microwave physical vapor transport (PMPVT) has been developed in this work. The photoluminescence (PL), absorbance, Raman spectra and the mechanism of CdS crystal growth have been investigated. Furthermore, plasma-enhanced microwave chemical vapour transport (PMCVT) synthesis of CdS with additional chemical transport agents has been explored. In addition, other II-VI chalcogenides were also synthesized by PMPVT.

Presented here are three organic-decorated manganese selenidostannates with various structural dimensionalities (D), namely, 1D – SnSe3Mn(en)2 (en = ethylenediamine) (1), 2D – SnSe3Mn(en) (2) and 3D – MnSnSe4Mn(en)2 (3). 2 and 3 represent the first 2D and 3D organic-decorated Mn–Sn–Se compounds, respectively. A structural transformation was observed between 1 and 2.

Two mixed-valent thioarsenates, namely (enH2)(4.5)[In(As(V)S4)3][As2(III)(μ-S2)S3]Cl (1) and (enH2)MnAs(III)As(V)S6 (2) (en = ethylenediamine), have been solvothermally synthesized and characterized. Thermal stability, magnetic and mixed-valent optical properties, as well as theoretical band structures and DOSs, of 1 and 2 have also been studied.

A novel thioantimonate(III), namely, [Ni(phen)(3)](2)Sb(18)S(29) (1; phen = 1,10-phenanthroline), has been solvothermally synthesized. Its structure features a three-dimensional framework with the largest channels in thioantimonates. The chiral [Ni(phen)(3)](2+) cations and the Sb:S ratio (1:1.611) in 1 are unique among those in the reported thioantimonates. The thermal stability, optical properties, and electric conductivity as well as the theoretical band structure and density of state of 1 have also been studied.

A solid surface fluorimetry approach was established for direct determination of anthracene (An) adsorbed onto fresh mangrove leaves. The experimental results showed that the linear dynamic ranges for determination of An adsorbed onto Avicennia marina (Am), Bruguiera gymnorrhiza (Bg), Kandelia candel (Kc) and Rhizophors stylosa (Rs) leaves varied from 0.92 to 8.71, 0.089 to 0.70, 0.063 to 5.61 and 0.11 to 1.82 microgg(-1), with detection limits of 5.77, 1.79, 4.29 and 1.42 ngg(-1), respectively, and with a relative standard deviation less than 10% (n=5). The experimental recovery results for adsorbed An on Am, Bg, Kc and Rs leaves were among 79.2-85.9, 75.1-102.3, 70.2-93.8 and 73.1-110.8%, respectively. Using the established method, we investigated the effects of exposure time of An and the different quantity of leaf-wax among the four species of mangrove on the amount of An adsorbed. Under the same experimental conditions, the adsorption of An on the upper and lower sides of the same mangrove leaf, and at different regions on the upper side of the same mangrove leaf were also studied. The results demonstrated that the leaves of different mangrove species contained different quantities of leaf-wax, and with the same exposure conditions to An, the quantity of leaf-wax among the four species showed a significant positive correlation with the amount of An adsorbed onto the leaves.