Antisolvent Method Research Articles

One-step anti-solvent associated method for high performance two-dimensional perovskite photodetectors fabrication at low temperature

The two-dimensional (2D) organic-inorganic perovskite of unique optical properties and improved stability holds great potential in high-performance perovskite optoelectronic applications. However, a huge challenge to manufacture continuous thin films at large scale and low cost is still unresolved. Here, a facile method to fabricate high quality (PEA)2PbI4 thin films at low temperature in the air condition by one-step anti-solvent associated method was firstly proposed. The mechanism of nucleation sites formation and grain growth rates governed by the polarity and saturated vapor pressure of anti-solvents and annealing temperature was disclosed. By comparing different anti-solvents at various annealing temperatures, high quality thin films with the lowest annealing temperature of 80 ℃ were achieved by using toluene. A simple planar photodetector was configured, with the Responsivity (Rs) and Detectivity (D*) of 752 μA/W and 2.76×108 Jones with active area of 150 μm × 8000 μm, respectively, and the stability keeping 92% after 90 cycles under continuous light illumination and nearly 100% remaining after 10 weeks without additional encapsulation. This method offers a simple and low cost approach for manufacturing high quality 2D perovskite films and high performance photodetectors at low temperature for industrial applications.

Low-temperature synthesis of stable blue Cesium lead bromide perovskite nanoplates with high quantum efficiency for display applications

Despite heavy research, the efficiencies of blue perovskite light-emitting diodes (LEDs) lag behind those of their green and red cousins. One of the most critical problems is the lack of technology to obtain both high blue emission and spectral stability of perovskite in thin films. Herein, we employ low-temperature synthesis of CsPbBr3 nanoplates (NPLs) by anti-solvent assisted crystallization method using green ethylacetate anti-solvent, which show high absolute photoluminescence quantum yield (PLQY = 90.2%), blue emission at 464 nm with a narrow emission line width (15 nm), small Stokes shift (5 nm) and the average PL decay lifetime (6.91 ns). Significantly, there is no obvious QY loss at different storage conditions. Furthermore, the PL can be tuned from blue to green (457–513 nm) by controlling the amount of precursor injected into anti-solvent. For the first time, we utilize all-bromide-based inorganic perovskites to fabricate ultraviolet-pumped white LEDs (UV-WLEDs) and optimize the chromaticity coordinate of WLEDs, whose CIE color temperature (CCT) is 6083 K. Finally, highly efficient blue LED device using CsPbBr3 nanoplates (464 nm) with high external quantum efficiency (EQE) of 2.03% was fabricated and spectral stability of CsPbBr3 nanoplates under constant current density was demonstrated. This work will be expected to facilitate the development of the blue light source for WLEDs and displays.

An Integrated Bulk and Surface Modification Strategy for Gas‐Quenched Inverted Perovskite Solar Cells with Efficiencies Exceeding 22%

Inverted perovskite solar cells (PSCs) prepared by the antisolvent method have achieved power conversion efficiencies (PCEs) of over 23%, but they are not ideal for device upscaling. In contrast, gas‐quenched PSCs offer great potential for upscaling, but their performance still lags behind. Herein, the gas‐quenched films through both surface and bulk modifications are upgraded. First, a novel surface modifier, benzylammonium thiocyanate, is found to allow remarkably improved surface properties, but the PCE gain is limited by the existence of longitudinally multiple grains. Thus, methylammonium chloride additive as a second modifier to realize monolithic grains is further utilized. Such an integrated strategy enables the average open‐circuit voltage of the gas‐quenched PSCs to increase from 1.08 to 1.15 V, leading to a champion PCE of 22.3%. Moreover, the unencapsulated device shows negligible degradation after 150 h of maximum power point operation under simulated 1 sun illumination in N2.

Template‐Guided C8‐BTBT/MAPbBr3/C8‐BTBT Heterostructures for Broadband Bipolar Phototransistors

AbstractBipolar junction transistor (BJT) has had an unprecedented impact on the electronic industry and helped to usher in the digital revolution prominently. However, the critical part of BJT, p–n junction, is formed by carefully incorporating substitutional impurities in traditional bulk semiconductors and it is difficult to implement in nanostructured device. In this work, a floating‐base BJT device is demonstrated by growing C8‐BTBT/MAPbBr3/C8‐BTBT PNP heterostructure in liquid phase. Growth of two semiconductor microwires into a crisscross heterojunction is achieved through template‐guided printing and antisolvent crystallization method. The proof‐of‐concept phototransistor demonstrates broadband light absorption from ultraviolet (UV) to visible spectral region, which exhibits enhanced photoresponsivities of 1.28 A W–1 to UV and 0.425 A W–1 to visible light, respectively. In addition, the improved photoelectric amplification behavior of C8‐BTBT/MAPbBr3/C8‐BTBT phototransistor is observed by comparing with the performance of C8‐BTBT/MAPbBr3 two‐component photodiode. The maximal gain can reach up to ≈600 and can be maintained ≥200 at the positive bias. The device provides new attractive prospects in the investigation of integrated circuits based on micro‐structured semiconductors.

Circular Hazelnut Protection by Lignocellulosic Waste Valorization for Nanopesticides Development

Hazelnut represents a relevant agro-food supply chain in many countries worldwide. Several biological adversities threaten hazelnut cultivation, but among them bacterial blight is one of the most feared and pernicious since its control can be achieved only by prevention through the observation of good agricultural practices and the use of cupric salts. The aim of this work was to evaluate the lignocellulosic biomasses obtained from hazelnut pruning and shelling residues as a renewable source of cellulose nanocrystals and lignin nanoparticles and to investigate their antimicrobial properties against hazelnut bacterial blight. Cellulose nanocrystals were obtained through an acid hydrolysis after a chemical bleaching, while lignin nanoparticles were synthesized by a solvent–antisolvent method after an enzymatic digestion. Both collected nanomaterials were chemically and morphologically characterized before being tested for their in vitro and in vivo antibacterial activity and biocompatibility on hazelnut plants. Results indicated the selected biomasses as a promising starting material for lignocellulosic nanocarriers synthesis, confirming at the same time the potential of cellulose nanocrystals and lignin nanoparticles as innovative tools to control hazelnut bacterial blight infections without showing any detrimental effects on the biological development of treated hazelnut plants.

Implementation of sonicated continuous plug flow crystallization technology for processing of acetylsalicylic acid reaction mixture

An effective way to ensure proper mixing and thereby realize maintenance-free operation of the clogging-sensitive continuous tubular crystallizers is the utilization of ultrasound-irradiation. Considering this, our research aimed to develop an ultrasonicated plug flow crystallization process to separate and purify a multicomponent acetylsalicylic acid (ASA) flow reaction mixture with antisolvent and combined cooling-antisolvent method. The influence of process parameters – temperature, antisolvent to ASA solution ratio, mean residence time – on purity, yield, productivity, product size, and size distribution was investigated applying a 23 full factorial experimental design. In further analysis, the alteration of product quality and quantity was studied by reducing the ultrasonicated tubing length and increasing the feeding rate, which could be important for industrial applicability. It was found that ultrasonication results in robustness against process parameter modification regarding product quality producing purified, small (<50 μm), consistent quality product while enabling to reach 89% yield even with 30 s residence time.

Highly crystalline lead-free Cs3Sb2Br9 perovskite microcrystals enable efficient and selective photocatalytic oxidation of benzyl alcohol

Selective oxidation of alcohols to the corresponding aldehydes constitutes a great challenge in organic and green chemistry, which typically requires environmentally unfriendly oxidants/catalysts or relatively harsh conditions (high temperature & pressure). Herein, we report an eco-friendly perovskite-based photocatalyst, in which all-inorganic perovskite Cs3Sb2Br9 microcrystals with high crystallinity were prepared using a facile antisolvent method at various temperatures. For the photocatalytic oxidation of benzyl alcohol, the Cs3Sb2Br9 microcrystal photocatalysts exhibited up to 77% conversion and 88% selectivity toward benzaldehyde under oxygen atmosphere and visible-light illumination. More significantly, the comparative experimental results in air were close to those in oxygen, with the observation of 96% conversion and 94% selectivity for the optimized conditions under air atmosphere. Notably, the conversion of our best-performing photocatalyst was 32 and 6.4 times higher than that of the lead-based CsPbBr3 and FAPbBr3 (FA: formamidinium) perovskites, respectively. Furthermore, the underlying photocatalytic oxidation mechanism was proposed by the electron spin resonance (ESR) and the controlled experiments using specific scavengers. This study sheds light on promising new photocatalytic applications of the lead-free metal halide perovskites.

Stable Metal–Halide Perovskite Colloids in Protic Ionic Liquid

Stable Metal–Halide Perovskite Colloids in Protic Ionic Liquid

Inorganic‐Cation Pseudohalide 2D Cs2Pb(SCN)2Br2 Perovskite Single Crystal (Adv. Mater. 7/2022)

2D Perovskites Cs2Pb(SCN)2Br2, an inorganic-cation pseudo-halide 2D phase perovskite single crystal, is grown by a simple antisolvent vapor-assisted crystallization method, as reported by Chu-Chen Chueh, Anita W. Y. Ho-Baillie, and co-workers in article number 2104782. Cs2Pb(SCN)2Br2 exhibits a reversible first-order phase transformation to CsPbBr2 at 450 K and has a low exciton binding energy amongst the 2D perovskites. Demonstration for photodetector application shows respectable responsivity and detectivity.

Cs incorporation via sequential deposition for stable and scalable organometal halide perovskite solar cells

In this study, uniform Cs distribution in an organometal halide perovskite (OHP) film was achieved via sequential deposition method entailing the dissolution of Cs compounds in dimethyl formamide (DMF) with inorganic components, as opposed to using isopropyl alcohol with organic components, and the thermal stability and crystallinity of the OHP film were enhanced by improving the structural stability through Cs incorporation. Additionally, the device performance and thermal stability of OHP solar cells were enhanced by Cs incorporation, which led to fewer defect sites and the suppression of defect generation in OHP films, as confirmed by optical and electrical analysis, improving the overall film quality. The sequential deposition method was more amenable to scaling up than the anti-solvent assisted one-step spin-casting method, as demonstrated by the sequential deposition of the OHP film uniformly over a substrate with size of 8 cm × 8 cm. The uniformly sequentially deposited OHP film was used to create a large-area 1 cm 2 OHP solar cell, which exhibited a high power conversion efficiency (PCE) of 16.77%. Further scalability of the sequentially deposited OHP solar cell was confirmed by highly uniform device performances by three cells on a single substrate with a negligible PCE standard deviation of 0.94%. • The uniform Cs distribution in OHP film is achieved via sequential deposition. • The thermal stability of the OHP film increased through Cs incorporation. • The performance and stability of the PeSCs is improved. • Uniform OHP film with large size is successfully fabricated by sequential deposition. • A p-i-n PeSCs with a size of 1 cm 2 was successfully fabricated.

Stable Lead‐Free Blue‐Emitting Cs3Cu2Br5 Single Crystal with Self‐Trap Exciton Emission for Optoelectronics

Owing to their excellent photoelectric properties, perovskite materials have broad application prospects; however, the toxicity of Pb limits the application of Pb‐based perovskite materials. To overcome this problem, Pb‐free perovskite materials are prepared by replacing Pb with nontoxic elements including Ge and Sn; nevertheless, the stabilities of these materials are low. Herein, single crystals of nontoxic Cu(I)‐based ternary metal halide (Cs3Cu2Br5) with outstanding stabilities and self‐trapped excition (STE) emission are constructed by an antisolvent method for the first time; these crystals exhibit central blue emission at 458 nm and large Stokes shifts. Photoluminescence (PL) intensities of the single crystals remain above 96.9% of their initial intensities when these crystals are exposed to an atmospheric environment for 90 days. Moreover, the stabilities of the Cs3Cu2Br5 single crystals are investigated by temperature‐dependent PL spectroscopy, which suggests a considerable exciton binding energy of 503 meV, and derivative thermogravimetric analysis, which indicate that the temperature of complete decomposition of Cs3Cu2Br5 is above 930 °C. Furthermore, a new class of white light‐emitting diodes with an ultrahigh color rendering index of 97.8 and satisfactory performance is produced using the Cs3Cu2Br5 single crystals. The study demonstrates significant potentials of Cu(I)‐based single crystals in the field of optoelectronics.

Hydrogel Microparticle-Templated Anti-Solvent Crystallization of Small-Molecule Drugs.

Conventional formulation strategies for hydrophobic small-molecule drug products frequently include mechanical milling to decrease active pharmaceutical ingredient (API) crystal size and subsequent granulation processes to produce an easily handled powder. A hydrogel-templated anti-solvent crystallization method is presented for the facile fabrication of microparticles containing dispersed nanocrystals of poorly soluble API. Direct crystallization within a porous hydrogel particle template yields core-shell structures in which the hydrogel core containing API nanocrystals is encased by a crystalline API shell. The process of controllable loading (up to 64% w/w) is demonstrated, and tailored dissolution profiles are achieved by simply altering the template particle size. API release is well described by a shrinking core model. Overall, the approach is a simple, scalable and potentially generalizable method that enables novel means of independently controlling both API crystallization and excipient characteristics, offering a "designer" drug particle system.

Vacuum Quenching for Large-Area Perovskite Film Deposition.

The removal of precursor solvents in perovskite wet films plays a vital role in controlling the quality of perovskite films and devices. The dripping antisolvent method (removing precursor solvents) has made great advances in small-area devices, but this method limits the preparation of large-area perovskite films. Vacuum quenching that evaporates solvents by dropping the pressure is a potential large-area manufacturing approach. Herein, we have conducted a systematic comparative study on these two methods of depositing perovskite films. It is found that vacuum quenching can obtain the same film quality and small-area device efficiency (∼22.5%) as the antisolvent method. However, on a large-area substrate, the fast vacuum quenching rate improves the solvent evaporation efficiency and nucleation density (i.e., forming a large number of crystal nuclei), thereby obtaining a more uniform and stable perovskite film. Notably, the manufacture window exceeds 10 min. As a result, the champion large-area (6 × 6 cm2) perovskite solar module exhibits an impressive efficiency (17.86%) and long-term operational stability. Furthermore, coupling slot-die coating, vacuum quenching can realize the industrial continuous deposition of large-area perovskite films, which is a potential route for large-scale production.

Characterization of Pickering Emulsion Stabilized by Colloidal Sodium Caseinate Nanoparticles Prepared Using Complexation and Antisolvent Method

Characterization of Pickering Emulsion Stabilized by Colloidal Sodium Caseinate Nanoparticles Prepared Using Complexation and Antisolvent Method

Improved highly efficient Dion-Jacobson type perovskite light-emitting diodes by effective surface polarization architecture.

Quasi-two-dimensional (quasi-2D) perovskites are emerging as promising materials for highly stable light-emitting diodes (LEDs). However, their lower charge transport mobilities and higher defect densities may constrain their light-emitting efficiency. Here, we combine an excessive-salt-assisted (ESA) process with antisolvent treatments to inhibit the defects in Dion-Jacobson-type perovskite LEDs. Such a method could improve the film quality and recombination efficiency. By further investigation, we found that artificially building a bulk junction interface and enhancing surface polarization could play a more important role in promoting the ability of charge carrier injection and recombination for high-performance LED devices. Accordingly, the DJ-type quasi-2D perovskite LED can achieve a high external quantum efficiency (EQE) of 7.1%.

Formation mechanisms of CsPbBr3/Cs4PbBr6 microscale composites assisted with imidazolium cations and their device applications.

The instability of all-inorganic perovskite nanocrystals (NCs) remains a major challenge to their practical applications in displays and lighting. In order to improve their environmental resistance, highly luminescent CsPbBr3 NC embedded Cs4PbBr6 microcrystals (MCs) have been fabricated by an anti-solvent reprecipitation method with the assistance of 1-alkyl-3-methyl-imidazolium bromides. The heterostructure of the MCs is investigated in detail, and their formation mechanism is discussed in terms of the dissolution-precipitation equilibria and the total energy of variously scaled nanoparticles via density functional theory (DFT) calculations. Although the imidazolium ligands are not directly capping with the inner CsPbBr3 NCs, they are important to the formation of these MCs. The MCs exhibit better thermal resistance compared to conventional CsPbBr3 NCs prepared by the hot-injection method. Additionally, a prototype white light-emitting diode (WLED) was fabricated to demonstrate its practical application prospects. Thanks to the narrow emission bands and enhanced stability of the MCs, the WLED shows greater performance compared to bare perovskite NCs, indicating its great potential as a green phosphor in lighting and display applications.

One-Step Anti-Solvent Associated Method for High Performance Two-Dimensional Perovskite Photodetectors Fabrication at Low Temperature

One-Step Anti-Solvent Associated Method for High Performance Two-Dimensional Perovskite Photodetectors Fabrication at Low Temperature

Fenofibrate-Nicotinamide Cocrystals: Molecular Docking Studies and Evaluation in Tablet Dosage Form

The objectives of present investigation were to evaluate prepared cocrystals of fenofibrate and nicotinamide for pre-compression characteristics, docking studies for target peroxisome proliferator-activated receptor alpha, evaluate performance of cocrystals in tablet dosage form and to carry out in vivo antihyperlipidemic activity. The cocrystals were prepared by antisolvent addition method. Docking studies of cocrystals and pure fenofibrate against of target peroxisome proliferator-activated receptor alpha were carried out by using PyRx (version 0.8) docking tool, AutoDock Vina as docking program. The prepared cocrystals were evaluated for pre-compression properties like angle of repose, bulk density and Carr’s index. Cocrystals were formulated in tablet dosage form and evaluated for official and unofficial quality control tests. The antihyperlipidemic activity carried out in rats by using Triton X-100 induced hyperlipidemia model. Cocrystals binds with peroxisome proliferator-activated receptor alpha with more binding affinity as compared with fenofibrate. Cocrystal shows binding energy of -9.3 kcal/mol while fenofibrate shows -8.5 kcal/mol. The pre-compression properties were within the limits of United States Pharmacopeia guidelines. The pure fenofibrate tablet showed 24.7 % drug release at the end of 90 min and cocrystal based tablet showed 100 % at 45 min. There was no statistically significant difference in values for all biochemical parameters in case of in vivo activity for cocrystals in comparison with pure fenofibrate. From the docking studies we can conclude that cocrystals showed stronger more substantial formed stable complexes with target peroxisome proliferator-activated receptor alpha, but no statistically significant difference in pharmacodynamic studies.

The preparation of novel core–shell suppressor and its suppression mechanism on coal dust explosion flame

To explore ways of further guaranteeing the production safety of coal processing, novel powder suppressors with core–shell structure were prepared through anti-solvent crystallization method by loading potassium oxalate (K) and ferric citrate (T) on treated waste molecular sieve. Flame propagation experiments were performed to investigate the effects of suppressors prepared under different conditions on coal dust flame propagation. The results showed that when K and T were added simultaneously at the loading of 30 wt%, the suppressor S@T-K showed best suppression performance. The pyrolysis-oxidation mechanism of coal dust with and without suppressor S@T-K was analyzed using Coats-Redfern (C-R) method. After the suppressor was added, the activation energy increased by 11.55 kJ/mol and 15.37 kJ/mol in the rapid and slow pyrolysis stages, respectively. The activation energy values of the coal sample with and without the suppressor under different conversion ratios were further calculated using Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods. The average activation energy values during the rapid and slow pyrolysis stages both agree well with the C-R calculation, which verifies the appropriateness of using C-R method to identify the reaction mechanism. By combining the coal dust flame propagation behaviors with the pre- and post-explosion characterization results, it is proposed that waste molecular sieve composite powders with core–shell structure suppress flame propagation through the synergy of physical and chemical reactions.

Hot-Casting and Anti-solvent Free Fabrication of Efficient and Stable Two-Dimensional Ruddlesden-Popper Perovskite Solar Cells.

Owing to the durable environmental stability and tunable photophysical properties of the two-dimensional Ruddlesden-Popper (2D RP) perovskite, it has a great potential in stable perovskite solar cells (pero-SCs). However, almost efficient 2D RP pero-SCs are prepared by the hot-casting or anti-solvent assisted spin-coating method, which greatly limits their applications. Herein, a multifunctional strategy through introducing a novel organic salt, benzimidazolium iodide (BnI), as a spacer and KI as an additive is reported to successfully fabricate a high-quality Bn-based 2D RP perovskite film in the hot-casting and anti-solvent free spin-coating method. The entire conjugated backbone of benzimidazolium is expected to enhance charge carrier transport within the 2D RP perovskite film. And KI can lead to a preferred orientation and less defects in the 2D RP perovskite film. Then, a maximum power conversion efficiency (PCE) of 15.12% is obtained, which is the highest performance for 2D RP perovskite devices without the hot-casting or anti-solvent method. The unsealed device maintains 92.1% of its original performance when kept in air (40-45% relative humidity) for 720 h and 87.9% of the initial performance after 528 h of heating at 85 °C.