Bismuth Halides Research Articles

N‐Heterocyclic Thione‐Coordinated Dinuclear Bismuth(III) Trihalides with a Rare Geometry

AbstractTwo thione‐coordinated dinuclear bismuth(III) halides were isolated with a rare geometry and characterized using FT‐IR, NMR, and single‐crystal X‐ray diffraction techniques. The sterically less crowded N‐heterocyclic thione ligand gave bismuth(III) chloride‐thione complex in cis isomeric form, while the sterically more crowded N‐heterocyclic thione ligand gave dinuclear bismuth(III) bromide‐thione complex in facial isomeric form. Continuous shape measurement (CShM) revealed that the bismuth centres in cis‐bismuth(III) chloride‐thione complex adopts distorted octahedral geometry with the CShM values of 2.103, which is remarkably different compared to the facial‐dinuclear bismuth(III) bromide‐thione complex (1.071 and 0.391).

Multicomponent X-ray Shielding Using Sulfated Cerium Oxide and Bismuth Halide Composites.

Lead is the most widely used X-ray-shielding material, but it is heavy (density ≈ 11.34 g/cm3) and toxic. Therefore, the replacement of Pb with lightweight, ecofriendly materials would be beneficial, and such materials would have applications in medicine, electronics, and aerospace engineering. However, the shielding ability of Pb-free materials is significantly lower than that of Pb itself. To maximize the radiation attenuation of non-Pb-based shielding materials, a high-attenuation cross-section, normal to the incoming X-ray direction, must be achieved. In this study, we developed efficient X-ray-shielding materials composed of sulfated cerium oxide (S-CeO2) and bismuth halides. Crucially, the materials are lightweight and mechanically flexible because of the absence of heavy metals (for example, Pb and W). Further, by pre-forming the doped metal oxide as a porous sponge matrix, and then incorporating the bismuth halides into the porous matrix, uniform, compact, and intimate composites with a high-attenuation cross-section were achieved. Owing to the synergetic effect of the doped metal oxide and bismuth halides, the resultant thin (approximately 3 mm) and lightweight (0.85 g·cm-3) composite achieved an excellent X-ray-shielding rate of approximately 92% at 60 kV, one of the highest values reported for non-heavy-metal shielding materials.

A versatile approach for the immobilization of lead-free Cs3Bi2I9 perovskites for photocatalytic CO2 reduction

This work proposes a novel approach to immobilize the lead-free bismuth halide perovskite Cs3Bi2I9 in mica and cellular porous concrete supports. The perovskites were evaluated as visible-light active photocatalysts in the CO2 reduction to generate HCOOH with high energy conversion efficiencies. The approach ensured the material’s stability exposed to an aqueous medium under visible light irradiation. According to the results, the Cs3Bi2I9 particles exhibited a different morphology depending on the support used; its growth on mica favored the formation of well-defined hexagonal particles. Meanwhile, the porous concrete favored the formation of needle-like particles. Also, the optical characterization indicated that when the Cs3Bi2I9 particles grew as a thin film, their surface energy seemed higher, favoring the formation of layered structures related to the lattice defects. On the other hand, the concrete cellular offers a porous interconnected network, an excellent medium to encapsulate the Cs3Bi2I9 particles. These properties favored the formation of 2,570 µmol of HCOOH in the steady state with an energy conversion efficiency of up to 24.3%, which is higher than the required value to scale up the process. The analysis of the perovskite after the reaction revealed that the sample maintains its properties, and it shows the growth of flake-like particles on top of hexagonal particles, which eventually participate in the photocatalytic reaction. Also, it was demonstrated that the approach implemented here favored high thermal stability of the Cs3Bi2I9 perovskite.

Perovskite-Derived Bismuth with I- and Cs+ Dual Modification for High-Efficiency CO2 -to-Formate Electrosynthesis and Al-CO2 Batteries.

Bi-based materials are one of the most promising candidates for electrochemical CO2 reduction reaction (CO2 RR) to formate; however, the majority of them still suffer from low current density and stability that essentially constrain their potential applications at the industrial scale. Surface modification represents an effective approach to modulate the electrode microenvironment and the relative binding strength of key intermediates. Herein, it isdemonstrated that the surface comodification with halides and alkali metal ions from the conversion of Bi-based halide perovskite nanocrystals is a viable strategy to boost the CO2 RR performance of Bi for formate electrosynthesis. Cs3 Bi2 I9 nanocrystals are prepared by a hot-injection method. The as-prepared products feature well-defined hexagonal shape and uniform size distribution. When used as the precatalyst, Cs3 Bi2 I9 nanocrystals are converted to Cs+ and I- comodified Bi. The resultant catalyst exhibits high formate Faradaic efficiency close to 100%, and remarkable partial current density up to 44mA cm-2 in an H-cell and up to 276 mA cm-2 in a flow cell. Moreover, Cs3 Bi2 I9 is used as the cathode catalyst and paired with an Al anode in an Al-CO2 battery for simultaneous CO2 valorization and power generation.

Investigations on the stability of the ambient processed bismuth based lead-free A3Bi2I9 (A = MA; Cs) perovskite thin-films for optoelectronic applications

Lead (Pb)-free bismuth (Bi) halide-based hybrid perovskites exhibit promising optoelectronic properties with low toxicity and air-stability. Fully ambient processed and high-quality perovskite thin-films are much desired for the industrialization of perovskite solar cells. So far, most of the lead-free perovskite halide thin films are processed and fabricated inside the glove box with ppm level atmosphere-controlled environment due to their poor stability. In this work, we report a one-step solution process employing solvent engineering to obtain highly crystalline and uniform (CH3NH3)3Bi2I9 (MBI) and Cs3Bi2I9 (CBI) perovskite thin-films prepared completely under ambient atmosphere. We further verified the stability of these MBI and CBI perovskite thin-films by exposing them to the ambient air with relative humidity and at room temperature for 180 days. The comparative structural, surface morphology and optical analysis of the samples show that bismuth halide perovskite can be an ideal candidate for fabrication in ambient atmosphere.

A Semitransparent Silver–Bismuth Iodide Solar Cell with Voc above 0.8 V for Indoor Photovoltaics

Because the toxicity of lead (Pb) remains a potential threat to the commercialization of perovskite solar cells, silver–bismuth halides such as AgBiI4, AgBi2I7, Ag2BiI5, and Ag3BiI6 with band gaps of 1.8–1.9 eV and strong absorption are considered to be promising alternatives to Pb-based perovskites, not only for outdoor (1 Sun) but also for indoor photovoltaics because their band gap matches best with the indoor artificial light spectrum. To date, almost all studies have focused on improving the power conversion efficiency (PCE) under 1 Sun using thick absorber films made on mesoporous electron-transport layers. However, in this work, we aimed at developing optically semitransparent Ag2BiI5 solar cells that can be used indoor or on windows. We studied the effect of the precursor composition on the phase evolution, energy band levels, film morphology, and, eventually, solar cell performance. Through compositional engineering and thickness optimization, we accomplished the fabrication of a thin (∼100 nm Ag2BiI5) and semitransparent Ag2BiI5 solar cell that works with a power conversion efficiency of ∼2%, which is greater than many reported with thick and opaque films and slightly lower than the best recorded for Ag2BiI5. The cell shows an open-circuit voltage (Voc) of over 800 mV, the highest reported for Ag2BI5. More interestingly, while a thicker/opaque cell was found to work with a PCE of 5.0% under 1000 lx, the semitransparent cell shows a reasonable performance of 3.3% under the same light intensity.

Resistive switching and artificial synaptic performances of memristor based on low-dimensional bismuth halide perovskites

Resistive switching and artificial synaptic performances of memristor based on low-dimensional bismuth halide perovskites

A Mechanochemically Synthesized Hybrid Bismuth Halide as Highly Efficient Red Phosphor for Blue Chip‐Based WLED

AbstractIn recent decades, white light‐emitting diodes (WLEDs) assembled by blue light‐emitting diodes (LEDs) and down‐conversion phosphors have gained rapid development. Thereinto, red phosphors, especially for the ecofriendly and cost‐effective ones, serve an important role for the preparation of superior WLEDs. Herein, a halide compound with a 0D crystal structure, namely [PPh4]2[Bi2Br8(bp4do)(DMSO)2] (BiBrON, PPh4 = tetraphenylphosphonium, bp4do = 4,4′‐bipyridine 1,1′‐dioxide, DMSO = dimethyl sulfoxide) is synthesized at gram scale via a mechanochemical synthesis method. Photophysical properties of BiBrON are investigated in detail. BiBrON has the highest efficiency (78.20%) of red phosphorescence among the Bi‐based halides. The red emission of BiBrON is blue‐light‐excitable with 99.9% color purity and outstanding thermal stability below 400 K. The optical absorption‐emission mechanism in BiBrON is elucidated by the combination study of experiments and density functional theory calculations. BiBrON can be applied as a red phosphor in the blue LED chip‐based WLED with high color rendering index of 87.8, that is higher than the one fabricated utilizing commercial red phosphor (610 nm), and ideal Commission International de l'Eclairage chromaticity coordinate of (0.3282, 0.3311). This work demonstrates for the first time the great potential of Bi‐inorganic–organic hybrid material as phosphors applied for WLED.

A green and facile synthesis of lead-free hybrid organic-inorganic bismuth halides quantum dots for nanophotonics applications

There has been an urgent need to eliminate toxic lead from the popular halide perovskite for various photonics and optoelectronics applications. This is added by the use of dangerous and environment unfriendly chemical during the wet synthesis route. Herein we demonstrate the synthesis of lead-free halide perovskite – (PhA)BiI4 (phenylammonium tetraiodobismates) and PhABiBr4 (phenylammonium tetrabromobismates) quantum dots (QDs) in room ambient environment using eco-friendly solvent - Ethanol. FESEM-EDX analysis of PhABiI4 and PhABiBr4 confirm the 1:4 atomic ratio of Bi:I and Bi:Br. As revealed by HRTEM, the as-prepared PhABiI4 indicate the formation of QDs with sizes smaller than 10 nm. Similar morphology was observed for PhABiBr4 QDs, but smaller in size compared to PhABiI4. High optical transparency was observed, and optical bandgap was measured for both PhABiI4 and PhABiBr4 QDs at 2.25 eV for and 3.07 eV, respectively. Chromaticity studies under 365 nm irradiation reveal a bright cyan emission for the PhABiI4 and bright blue emission for the PhABiBr4 QDs. Large magnitude of nonlinear optical susceptibility, |χ(3)| were calculated in the order of 10−6 esu. The green and facile synthesis approach reported here represents an alternate avenue for the new applications of Bi-based perovskite particularly towards the next-generation nanophotonics technologies.

Magnetic Fano resonance enhanced second-harmonic generation in chiral hybrid bismuth halides

Magnetic Fano resonance provides a potential opportunity to control both linearity and nonlinearity of light for their low radiation loss and near-field enhancement. Previous investigations have demonstrated its significant enhancement of nonlinearity in a plasmonic structure and the 2D materials coupled to it. In this work, the enhancement of second harmonic generation (SHG) of hybrid bismuth halides at the important communication wavelength of 1550 nm with a magnetic Fano dip is theoretically studied. To this end, a hybrid system composed of two asymmetric silver square split rings (SSRs) and this chiral perovskite film is designed. The simulation results show that magnetic Fano-like resonance is induced at the destructive interface of two magnetic modes in the SSR dimer, which can be inherited to hybrid bismuth halides, thereby leading to the increase of four orders of magnitude in its SH near-field enhancement factor. With a peak intensity of 0.16 GW cm−2, the composite structure features a high SHG conversion efficiency of up to 1.6 × 10−3 at the Fano resonance position. By rotating the polarization angle of fundamental optical excitation, the emitted SHG signal is switched on–off. Our research provides a valuable thought for enhancing the nonlinear optical process of the perovskite films by coupling the magnetic modes.

Solvothermal Synthesis of Bismuth-Based Halide Perovskite Nanostructures for Photocatalytic Degradation of Organic Pollutants under LED Light Irradiation

The use of bismuth-based halide perovskites for photocatalysis has attracted increasing attention because of their matching photoelectric properties and the nontoxicity of bismuth metal. However, organic–inorganic halide perovskites with chloride as halides possess a large band gap, restricting their potential use in visible-light-activated photocatalytic processes. In this study, a bismuth-based halide perovskite nanostructure, tris(tetramethylammonium) nonachlorodibismuthate (((CH3)4N)3Bi2Cl9), has been successfully synthesized through a solvothermal process using a mixture of dichloromethane/N,N-dimethylformamide as both solvent and reagent. The results show that, when dichloromethane and N,N-dimethylformamide are combined simultaneously during synthesis, Bi-based halide perovskite nanostructures are formed with a reduced midgap-state-induced energy gap. The formation of ((CH3)4N)3Bi2Cl9 was confirmed through X-ray diffraction patterns and Fourier transform-infrared spectroscopy. The presence of localized states extended in the band gap (referred to as midgap states) was demonstrated by ultraviolet–visible diffuse reflectance and photoluminescence spectroscopy. The ((CH3)4N)3Bi2Cl9 samples exhibit super photocatalytic activity for Rhodamine B and tetracycline hydrochloride degradation in an aqueous solution under visible-light irradiation. The bismuth halide perovskite (BHP-30-30 sample) exhibited a Rhodamine B degradation efficiency of 99.4% in 30 min and a tetracycline hydrochloride degradation efficiency of 78.4% in 3 h. The fact that this catalyst is recyclable four times further demonstrates the promise of BHP-30-30 as a replacement visible-light-sensitive catalyst for removing organic pollutants.

Flexible, stable, and self-powered photodetectors embedded with chemical vapor deposited lead-free bismuth mixed halide perovskite films

The emerging revolution in the field of Internet of Things (IoT) necessitates the development of flexible, self-powered, and cost-effective photodetectors such as metal halide-based perovskite photodetectors. Lead-free ternary metal halides have emerged as a promising option having no technical barrier with regard to toxicity. However, the performance metrics of lead-free ternary metal-halide-based optoelectronic devices lags behind those of conventional lead-halide-based devices. In this study, we demonstrate that chemical-vapor-deposited methylammonium bismuth iodide (MA3Bi2I9 (MBI)) films and their mixed halide analogues (MA3Bi2I6Br3 (MBIB)) and MA3Bi2I6Cl3 (MBIC)) enhance the performance metrics and stability of photodetectors by enabling the growth of films with smooth and compact morphology. MBIC-integrated devices achieved a responsivity of ∼ 0.92 A/W and specific detectivity of ∼ 2.9 × 1013 Jones under no bias and UV (382 nm) illumination, which is approximately-three times higher than MBI counterparts. They also exhibit outstanding operational stability by maintaining 94 % of the photoresponse after illumination for 500 h (382 nm wavelength at light intensity of 1.0 mW/cm2) in ambient air. Furthermore, these devices show satisfactory mechanical stability, with the attenuation being as low as 15 % of initial photoresponse after bending for 5,000 cycles at 5 % tensile strain. Our findings indicate that MBIC film-integrated devices have immense potential in optoelectronics.

Lead-free CsBi3I10 perovskite based photo-enhanced triboelectric nanogenerator

Perovskites have become promising candidates for triboelectric nanogenerators (TENGs) because of their excellent electrical and dielectric properties. Also, and the as-fabricated triboelectric-photoelectric coupled TENG based on those semiconductor characteristics can effectively enhance the device output performance. Herein, a low-toxic lead-free bismuth halide perovskite CsBi3I10 (CBI) film was proposed as triboelectric material for the first time, and a photo-enhanced TENG was designed based on CBI owing to its broad absorption properties. The CBI based TENG exhibits the highest voltage of 158 V and current density of 45.5 mA m−2 in dark condition. Furthermore, under illumination, the triboelectric output of voltage and current are increased by about 21.7% and 15.8% respectively, and the power density of the device can reach up to 4.95 W m−2. This work not only initiates a new route for applying lead-free perovskite in TENGs but also presents a hybrid TENG for simultaneously harvesting mechanical and light energy based on the triboelectric-photoelectric coupling effect.

Highly Anisotropic Second-Order Nonlinear Optical Effects in the Chiral Lead-Free Perovskite Spiral Microplates

Chiral metal halide perovskites with intrinsic asymmetric structures have drawn increased research interest for the application of second-order nonlinear optics (NLO). However, designing chiral perovskites with the features of a large NLO coefficient, high laser-induced damage thresholds (LDT), and environmental friendliness remains a major challenge. Herein, we have synthesized two chiral hybrid bismuth halides: (R/S-MBA)4Bi2Br10 spiral structure microplates, templated by chiral (R/S)-methylbenzylamine (R/S-MBA). The as-grown chiral lead-free perovskite spiral microplates exhibit a recorded second harmonic generation (SHG) effect with a large effective second-order NLO coefficient (deff) of 11.9 pm V-1 and a high LDT of up to 59.2 mJ cm-2. More importantly, the twisted screw structures show competitive circular polarization sensitivity at 1200 nm with an anisotropy factor (gSHG-CD) of 0.58, which is about 3 times higher than that of reported Pb-based chiral perovskites. These findings provide a new platform to design multifunctional lead-free chiral perovskites for nonlinear photonic applications.

高稳定性铋基钙钛矿纳米晶的可控合成: 结构和光物 理性质

Recently, cesium bismuth halide perovskites have emerged as potential substitutes to their counterparts, cesium lead halide perovskites, owing to their low toxicity. However, the photophysics of cesium-bismuth halides nanocrystals (NCs) have not yet been fully rationalized because their structures remain highly debated. The ultraviolet-visible (UV-vis) absorption along with other photophysical properties such as the nature and lifetime of the excited states vary considerably across the previous reports. Here, we successfully synthesize pure Cs3BiBr6 and Cs3Bi2Br9 NCs via a modified hot-injection method, where the structure can be easily controlled by tuning the reaction temperature. The UV-vis absorption spectrum of the pure Cs3Bi2Br9 NCs features two characteristic peaks originating from the absorption of the first exciton and second exciton, respectively, which ultimately clarifies the debate in the previous reports. Using femtosecond transient absorption spectroscopy, we systematically investigate the excited state dynamics of the Cs3Bi2Br9 NCs and reveal that the photoexcited carriers undergo a self-trapping process within 3 ps after excitation. More intriguingly, the Cs3Bi2Br9 NCs prepared by this method show much better photostability than those prepared by the ligand-assisted reprecipitation process. Photodetectors based on these Cs3Bi2Br9 NCs show a sensitive light response, demonstrating the definite potential for breakthrough optoelectronic applications.

Mixed valence Sn doped (CH3NH3)3Bi2Br9 produced by mechanochemical synthesis.

Bismuth halides with formula A3Bi2X9, where A is an inorganic or organic cation, show desirable properties as solar absorbers and luminescent materials. Control of structural and electronic dimensionality of these compounds is important to yield materials with good light absorption and charge transport. Here we report mechanochemical reaction of (CH3NH3)3Bi2Br9 with SnBr2 at room temperature in air, yielding a material with strong absorption across the visible region. We attribute this to mixed valence doping of Sn(II) and Sn(IV) on the Bi site. X-Ray diffraction shows no secondary phases, even after heating at 200 °C to improve crystallinity. X-Ray photoelectron spectroscopy suggests the presence of Sn(II) and Sn(IV) states. A similar approach to dope Sn into the iodide analogue (CH3NH3)3Bi2I9 was unsuccessful.

Synthesis and optical characterization of lead-free phenylenediammonium bismuth halide perovskites: a long charge carrier lifetime in phenylenediammonium bismuth iodide

Here we report the synthesis and properties of some lead-free organic bismuth halides. β-(PPD)2Bi2I10 has the longest average charge carrier lifetime (>1 μs) of the materials studied here, of the same order of magnitude as that of (CH3NH3)PbI3 and has a low band gap.

Heteroleptic six-coordinate bismuth(iii) complexes with 2-acetylthiophene thiosemicarbazones: synthesis, characterization, and biological properties

Synthesis, characterization, crystal structure determination, antiproliferative and antimicrobial studies of five bismuth(iii) halide complexes with 2-acetylthiophene thiosemicarbazones are presented herein.

Correction: Understanding the ultraviolet, green, red, near infrared and infrared emission properties of bismuth halide double perovskite

Correction for ‘Understanding the ultraviolet, green, red, near infrared and infrared emission properties of bismuth halide double perovskite’ by Anjun Huang et al., Inorg. Chem. Front., 2022, 9, 6379–6390, https://doi.org/10.1039/D2QI02053J.

Silver–Bismuth Halide Double Salts for Lead‐Free Photovoltaics: Insights from Symmetry‐Based Modeling

Silver–Bismuth Halide Double Salts for Lead‐Free Photovoltaics: Insights from Symmetry‐Based Modeling