Ambient Storage Conditions Research Articles

Physiological Changes in Okra (Abelmoschus esculentus L.) by Postharvest Application with Hexanal Containing Aqueous Formulations

Aim: Okra is a vegetable that holds a significant share in both domestic and export markets, but it is prone to desiccation and fungal spoilage, leading to a short shelf life. A laboratory study was undertaken to determine the effects of hexanal containing aqueous formulation to improve the shelf life of okra with the objective to maintain the best quality of pods for end consumer acceptance.
 Study Design: Factorial Completely Randomized Design was followed with three replications.
 Place and Duration of Study: The study was conducted in laboratory conditions, Department of Vegetable Science, Horticultural College and Research Institute, Coimbatore during 2021-2022
 Methodology: In this study, TNAU released nanoformulation– TNAU FRUITY FRESH – ENHANCED FRESHNESS FORMULATION consisting of 2% Hexanal, 10% Formulation ingredients, 88% Deionized filler. and hexanal was used at varying concentrations for imposing treatments on freshly harvested, uniform sized undamaged tender pods of bhendi hybrid COBh H4 (TNAU released hybrid) using spray and dip methods under ambient and cold storage conditions and physiological parameters were assessed.
 Results: As per the investigation, 2% Enhanced Freshness Formulation using dip method in cold storage conditions slower the physiological loss in weight, preserves the L*, a*, b* value, extend the shelf life and preserved the quality for consumer acceptance during storage 9 days as compared to control.
 Conclusion: The study gave the knowledge of hexanal containing aqueous formulation and their effectiveness to use as post-harvest technology tool for okra.

Fresh Insight: Enhancing Verdant Leafy Vegetable’s Shelf Life Via Modified Atmosphere Packing and Storage

This study aimed to enhance the durability of selected green leafy vegetables, including Lettuce and Palak, by manipulating influential factors such as storage conditions (Ambient (35±5°C) and Refrigerated (5±5°C)), packing substrate (Low-density polyethylene and High-density polyethylene covers), and gas composition using modified atmosphere packaging. Factorial completely randomized design (FCRD) was employed, incorporating a total of 12 treatments for each crop. The evaluation primarily relied on calculating physiological weight loss. Lettuce showed optimal results with treatment T5 (0.38%) exhibiting superior performance, followed by T6 (0.45%) and T3 (0.58%) under ambient conditions. Similarly, for palak, T5 (0.18%) outperformed T3 (0.19%) and T2 (0.37%). Thus, it is advisable to adopt T5 (R1G3M1) as the preferred treatment with T3 (R1G2M1) as a viable alternative for ambient storage conditions. Refrigerated lettuce performed optimally with T11 (0.54%) leading, followed by T7 (0.56%) and T9 (0.69%). Similarly, palak exhibited superior results with T9 (0.61%) in the fore, succeeded by T11 (0.77%) and T7 (0.97%). Notably, produce stored under ambient conditions had a relatively short shelf life of approximately 5 days, while refrigeration extended it to 15 days, after which a decline in quality was observed across all treatments. Therefore, refrigerated produce has an extended shelf life, with T9 (R2G2M1) followed by T7 (R2G1M1) yielding highly favorable outcomes.

Quantitative Insight into PCA Formation following Different Chlorhexidine Activation Methods in Endodontic Treatment.

The aim of the study was a quantitative analysis of p-chloroaniline (PCA) formation during 2% CHX activation with US and MDI methods in a root canal-like environment with the HPLC-DAD method and, thus, a safety assessment of US and MDI agitation of CHX in endodontic treatment. Two percent CHX was activated with the US method using ISO 30 and 35 K-file, and the MDI method using ISO 30.06 and 35.06 GP cones for 15, 30, 60, and 90 s. PCA concentration was assessed with the HPLC-DAD method. PCA concentration was also assessed for 2% CHX after 0, 3, 18, and 21 days of storage in ambient conditions. PCA was detected in all samples in all methods of activation. The concentration of PCA was dependent on time of activation in US ISO 30 and ISO 35 group (p < 0.05). In the MDI ISO 30.06 and ISO 35.06 groups, a similar trend was observed but without statistical significance (p > 0.05). PCA was detected in shelf-stored 2% CHX and the concentration was related to the time of storage. PCA is released after CHX activation with US and MDI, but mean concentrations are not higher than those observed from self-degradation of shelf-stored 2% CHX.

Effect of Aqueous n-Butanol Treatments on Shelf-Life Extension of Longkong Fruit during Ambient Storage

The pericarp of the Longkong fruit rapidly browns during ambient storage, typically reducing its shelf life to between 3 and 7 days. Recently, n-butanol has demonstrated a promising effect in preventing this deterioration, extending the shelf life of tropical fruits to more than a week. The present study exploited this opportunity to examine the exogenous application of aqueous n-butanol at various concentrations (0.2–0.6%) in controlling pericarp browning and suppressing different oxidoreductase enzymes in the pericarp under prolonged ambient storage conditions (8 days). Every two days, the fruit pericarps were tested for color (lightness (L*), redness (a*), and yellowness (b*)), browning index (BI), membrane permeability loss (MPL), malondialdehyde (MDA) content, total phenolic content (TPC), and reactive oxygen species (ROS). Enzymes including phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), phospholipase D (PLD), lipoxygenase (LOX), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) were also analyzed. All sample test results showed that increased storage significantly impacted color characteristics (decreased L*, b* and increased a*, and BI). MPL, MDA, and ROS also continuously increased. Furthermore, the browning-related enzymes (PAL and PPO), membrane-degrading enzymes (PLD and LOX), and antioxidant enzymes (SOD, CAT, and GPX) continuously increased in all pericarp samples throughout the storage. Among the samples, pericarp color, BI, MPL, MDA, PAL, PPO, PLD, and LOX were significantly high in the control samples, consequently adversely affecting the quality and shelf life of Longkong. On the other hand, the n-butanol-treated samples significantly controlled the loss and all problematic enzymes while improving the activities of SOD, CAT, and GPX in the pericarp. Furthermore, the positive effect of n-butanol application was dose-dependent; higher concentrations (0.4–0.6%) performed well in protecting the fruit from deterioration.

Combined immobilized lipases for effective biodiesel production from spent coffee grounds

This work describes the enzymatic transesterification of the oil extracted from SCGs for synthesis of biodiesel as a promising alternative to diesel fuels based on petroleum. Biocatalysts from various sources were tested for biodiesel synthesis using coffee oil among which CaCO3- immobilized Staphylococcus aureus and Bacillus stearothermophilus showed the highest conversion yields (61 ± 2.64% and 64.3 ± 1.53%, respectively) in 4 h. In further optimizing reaction parameters, methanol to oil molar ratio, biocatalyst quantity, water content, as well as incubation time and temperature markedly improved oil-to-biodiesel conversion up to 99.33 ± 0.57 % in a solvent free reaction after 12 h at 55 °C. A mixture of inexpensive CaCO3-immobilized bacterial lipases at a 1:1 ratio was the best environment-friendly catalyst for biofuel synthesis as well as the ideal trade-off between conversion and cost. Obtained coffee biodiesel remained stable beyond 40 days at ambient storage conditions and its chemical characteristics were comparable to those of other known biodiesels according to the European requirements (EN14214). Collectively, SCGs, after oil extraction, could be an ideal substrate for the production of an environment-friendly biodiesel by using appropriate mixture of CaCO3-immobilized lipases.

Encapsulation, characterisation and incorporation of chebulagic acid from beleric (Terminalia Bellirica) fruits in orange juice

SummaryChebulagic acid (CA), found in beleric (Terminalia bellirica) fruit powder, has various biological activities. This study aims to encapsulate CA to overcome its solubility, astringency and bitter taste issues and determine its properties. The encapsulated chebulagic acid (ECA) was incorporated into orange juice (OR), and a storage stability study at ambient temperature (25 ± 2 °C) and sensory analysis using a 9‐point hedonic scale were conducted. The highest encapsulation efficiency (89.24% ± 0.08%), antioxidant activity (96.82% ± 0.03%) and considerable powder yield (~59.3% ± 1.07%) with better water absorption index (0.64 ± 0.008 g/g), water solubility index (98.04 ± 0.016/100 g) and swelling capacity (0.055 ± 0.002 g/g) were achieved at 140 °C spray drying temperature with 60% maltodextrin and 40% gum Arabic. At the ambient storage conditions (25 ± 2 °C), the storage stability of ECA was 640 days (54.19% ± 0.02%), CA was 130 days (52.46% ± 0.14%) and the addition of ECA increased the OR's storage stability to 200 days (50.13% ± 0.59%) with respect to the antioxidant activity. From the sensory evaluation, the OR and OR added with 0.2 g/100 mL ECA samples were preferred by the 100 panellists and liked immensely. Overall, the encapsulation of CA successfully masked the astringency and bitterness, improving the CA's stability and increasing the orange juice's storage stability with more consumer acceptability.

Flavour enhancement strategy for herbal beverages and kinetic modelling of their antioxidant and sensory properties in accelerated storage conditions

Herbal infusions and beverages are part of culinary practices and home remedies of many ethnic groups globally. Centella asiatica, Enhydra fluctuans, Eryngium foetidum and Marsilea minuta are four important herbs that used to be consumed in different East and South Asian countries due to their health benefit. The herbs are not very acceptable by the millennials due to their off flavour and bitterness. In this study, Centella asiaitica was found to be an appropriate candidate for herbal beverages among the said four herbs. A Centella based beverage was developed that can deliver high antioxidant activity together with acceptable sensory properties. Out of the two common methods of herbal beverage preparation (i.e., infusion and decoction), infused beverage was adopted owing to its better sensory acceptance. The grassy flavour of the Centella infused beverage was masked with Khasi mandarin (Citrus reticulata) peel powder (90% Centella asiatica powder with 10% Khasi mandarin peel powder). Further, the accelerated storage study revealed that Centella asiatica powder was stable during ambient storage conditions (RH 61% and 32 °C), whereas the sensory acceptability, physicochemical properties, and the antioxidant potential of the powder degraded significantly at higher temperature (45 °C and RH 82%) especially with UV exposure. The impact of storage conditions on the most critical quality parameters i.e., colour, pH, and antioxidant capacity was estimated with a first-order degradation model. All the antioxidant capacity values showed different intrinsic rates of decay and the half-life of lipid peroxidation values was shortest among the four antioxidant capacity values. This work reports a unique accelerated stability study protocol to screen the packaging and storage conditions for herbal powders. Additionally, the results suggested, Citrus peel blending is a novel approach to make herbal beverages more acceptable to consumers due to better sensory perception and enhanced stability of the herbal powder.

Concentration of Phthalate Esters in Bottled Water: A Case Study in Effurun, Delta State, Nigeria

Phthalate esters (PAEs), a group of chemical compounds, are extensively used as additives in plastics. The objective of this study was to determine how much of a few target PAEs have leached into various samples of drinking water packaged in PET bottles in Effurun, Delta State, Nigeria as well as how ambient temperature, sunshine exposure, and cold storage conditions have affected the concentration of PAE. The concentrations of Di-ethyl-phthalate (DEP), di-butyl-phthalates (DBP), benzyl-butyl-phthalate (BBP), di-n-octyl phthalate (DnOP), and Bis-(2-ethyl-hexyl) phthalate (DEHP) were determined in bottled water samples. The concentrations of PAEs were determined using a gas chromatography coupled with a mass sepctroscopy analyzer (GC-MS). Phthalate compound was observed to be in all bottled water placed under different storage conditions; cold storage (CW), ambient storage (AW), and sunlight storage (SLW) for a period of 2, 4, 8, 12 and 16 weeks. However, the greatest leaching effect was observed in PET bottled water placed sunlight conditions for sixteen weeks with concentrations of; DEHP (2.1-11.2) µg/L, DEP (0.98-3.87) µg/L, DBP (2.98-13.8) µg/L. The results from this study indicated that, under various storage conditions, DEP, DBP and DEHP from PET bottles may leach more into the drinking water over a period of time under different storage conditions. The result additionally gave indication that DEHP; a known endocrine disruptor, with anti-androgenic and possible human carcinogen effects, exceeded the 6 µg/L USEPA Maximum Contamination Level (MCL) in drinking water, and also greater than 8 µg/L which is the indicated MCL by the World Health Organization (WHO).

Improved Device Performance and Stability in Organic Solar Cells by Morphology Control via Size‐Controlled Chevron‐Shaped Blades

Organic solar cells (OSCs) have been studied widely as renewable energy resources for a few decades owing to their technological advantages, including low cost, light weight, flexibility, and the potential of large area printing. To upgrade the active layers of OSCs into an optimized form, a simple and straightforward strategy is demonstrated by introducing two types of size‐controlled chevron (V)‐shaped blades to delicately control PM6:Y6‐based bulk heterojunction (BHJ) films under ambient conditions. A power conversion efficiency of 15.97% is achieved from the blade‐coating methods using a small‐sized V‐shaped blade (V1), compared with 14.31% using a conventional flat blade (F). Using blade coating based on V1 improves the phase separation and molecular crystallinity in the active layer, which lead to decreased trap‐assisted recombination and leakage current, finally increasing the short circuit current and fill factor. In addition, following these morphological changes in the optimal BHJ structure, the devices printed with V1 exhibit higher stability in the long‐term shelf‐life test (320 h storage in ambient conditions). Notably, strategy is a facile layer fabrication method that adopts V‐shaped blades to achieve high device performance and stability for the practical use of large‐area OSCs.

Storability of Different Hermetic Bags on Seed Quality Attributes of Maize in Khumaltar, Lalitpur

To evaluate the comparative superiority of exotic hermetic seed storage bags versus locally available bags supplemented with or without desiccants for on-farm seed storage of smallholders, an experiment was conducted in the National Seed Science and Technology Research Centre (NSSTRC) of Nepal Agricultural Research Council (NARC) from May 2017 to June 2019. Maize seed variety Manakamana-3 was allocated in 8 treatments based on storage devices with three replications in a completely randomized design (CRD). The 98% initial germinating seed was stored in eight different storage containers viz., S1, Super grain bag; S2, PICS bag; S3, Safe Grain bag; S4, 400-gauge plastic bag; S5, 400-gauge plastic double liner; S6, 400 gauge + metal bin; S7, 400 gauge + Zeolite beads; S8, 400 gauge + roasted wheat. All seed attributing data were taken in tri-monthly intervals for two and half years. In the first year, all seven treatments were found statistically at par results for germination above 85% by meeting the Nepalese maize seed standard except 400-gauze plastic bag-single liner. However, significant differences were seen in each treatment in the second year. Results on germination of storage structures with desiccants viz., 400 gauge + Zeolite beads, and 400 gauge + roasted wheat were found superior to any other storage structures such as PICS bag, Super grain bag, Safe grain bag, 400 gauge + metal bin, &amp; 400-gauge plastic double liner. Whereas, the single liner of a 400-gauge plastic bag was found non-suitable and found vulnerable to fungal infestation in long-run storage in ambient storage conditions. Hence, it was concluded that the locally fabricated seed storage bags provided equal results to exotic hermetic bags for one season seed storage in Mid-hill, humid and sub-temperate condition of Nepal and hence, found economical modified atmospheric storage (MAS) option for small holder farmers.

Hermetic storage of okra seed maintains seed longevity under changing environment.

Okra seed is vulnerable to loss of germination and vigor in variable storage conditions. High seed moisture contents (SMC) accelerate seed deterioration during storage thus keeping low seed moisture contents by storing seed in hermetic bags may help to retain seed longevity. Okra seed was equilibrated to four initial moisture levels including 8,10, 12 and 14% SMC. Seed was then packed and stored in traditional storage bags (Paper, cloth, polypropylene and jute bag) and hermetic Super Bag for 12 months under ambient conditions. Seed stored in hermetic Super Bag at 8 and 10% moisture contents maintained higher germination due to low seed moisture contents. Moreover, activities of α-amylases and total soluble sugars were higher while electrical conductivity of seed leachates, malondialdehyde (MDA) and reducing sugar contents were less in the seeds stored in hermetic Super Bag at 8 and 10% SMC as compared to seed stored in traditional storage bags. Hermetic storage at 14% moisture negatively influenced the seed quality. Moisture adsorption isotherms of okra seeds were developed at constant temperature of 25°C and varying levels of relative humidity from 60 to 90%. Moisture isotherms indicated no significant increase in seed moisture contents at 60 and 70% relative humidity (RH) in hermetic bags whereas a minor increase in seed moisture at 80 and 90% RH has been observed for the seeds incubated in hermetic bags. SMC significantly increased in traditional storage bags particularly in jute bag at high RH. In conclusion, storage in hermetic bags, maintain low seed moisture and high seed quality. Okra seed storage in hermetic bags at 8 and 10% SMC maintains seed longevity under ambient storage conditions.

Effect of Edible Coating on Shelf-life Enhancement of Papaya (Carica papaya L.) at Ambient Conditions

An experiment was conducted on the effect of edible coating on shelf-life enhancement of papaya (Carica papaya L.) at ambient conditions. The main aim of this study was to increase the shelf life of papaya by using edible coating. Postharvest losses in fruits is a serious problem due to rapid deterioration during storage. Use of edible coatings over fruits is used to improve their quality and enhance the shelf life. The main purpose of this study was to assess the effect of aloe vera gel, beeswax, paraffin wax and gelatine coating in extending the shelf-life of papaya including physico-chemical changes under ambient storage conditions. The experiment was laid out in completely randomized design (CRD) with 7 treatments and 3 replications. The treatment consisted of coating material with Aloe vera gel 0.5% (T1), Aloe vera gel 1%(T2), Aloe vera gel 1.5%(T3), Beeswax 6% (T4), Paraffin wax 100% (T5), Gelatin10%(T6), Control(T7) and freshly harvested papaya fruits. Statistical analysis revealed that among all the treatments, the maximum effect on extending the shelf-life and delaying the ripening was recorded in paraffin wax coated papaya fruits. Therefore, coating of papaya fruits with paraffin wax can be suggested as a post-harvest treatment to enhance the shelf-life.

Effect of natural oil coatings and antiageing compounds on shelf-life and quality of Daisy mandarin under ambient storage conditions

Effect of natural oil coatings and antiageing compounds on shelf-life and quality of Daisy mandarin under ambient storage conditions

Evaluation of Postharvest Chemical Treatment to Increase the Shelf Life of Guava L-49 and Allahabad Safeda Fruitsunder Ambient Storage

Physiologically mature, uniform fruits were thoroughly washed and dipped in aqueous solution of T0 (Untreated fruits), T1 (Boric acid at 200 ppm), T2 (Boric acid at 300 ppm), T3 (NAA at 100 ppm), T4 (NAA at 200 ppm), T5 (Salicylic acid at 300ppm), T6 (Salicylic acid at 400ppm) for five minutes. Fruits were placed in plastic trays and stored at ambient storage conditions for 12 days. The readings were observed after 4rd, 8th and 12th days. Physiological weight loss of fruits decreased with storage, further fruits treated with boric acid 300ppm recorded lower Physiological weight loss as compared to other treatments. Total Soluble Solids (TSS), Sugars were increased upto 12 days of storage.

Effect of Different Concentrations of 1-MCP and Varied Storage Environments on Physical Characteristics and Consumer Acceptability of Solo Papaya (Carica papaya L.) Fruits

The nature of papaya fruits is intently connected with their physical characteristics. Changes during aging are critical, yet uncontrolled ripening procedure can prompt fast degradation of quality. Despite the myriads of problems during storage and transportation or distribution, it is imperative to control ripening so as to reduce losses and maximize profit. A 4x2 factorial experiment in a completely randomized design was carried out to determine the effects of applying four concentrations of 1-MCP under two storage conditions on physical characteristics and consumer acceptability of ‘Solo’ papaya. During ripening, data on various physical characteristics including fruit firmness, cumulative weight loss (%), fruit skin color, shelf life and consumer acceptability were monitored. The 1-MCP treated fruit retained their firmness better than the control (untreated) fruit, regardless of whether they were stored under ambient or cold storage conditions. The percentage of weight loss decreased with increasing 1-MCP concentrations. In general, the 1-MCP treated fruit revealed a slower rate of color change compared to the control. The shelf-life of the papaya fruit treated with 1.5 ppm of 1-MCP and stored under ambient storage condition was extended by approximately 2 days. However, at the same concentration (1.5ppm) of 1-MCP but under cold storage condition, shelf life was extended by approximately 3 days.

Studies on the Preservation of Kokum (Garcinia indica) Rind Juice at Ambient Storage Condition

The study aimed to determine the effect of different concentrations of sodium benzoate at ambient storage condition on kokum rind juice. For this experiment, Factorial Completely Randomized Design (F.C.R.D.) was used. During the investigation, the chemical parameter, microbial analysis and sensory qualities of kokum rind juice were studied. During the 3 months of ambient storage condition, analysis was conducted at the interval of one month. The chemical parameter like acidity, TSS, reducing sugar, total sugar, anthocyanins and microbial analysis, sensory qualities changed significantly. From the experiment it can be concluded that the kokum rind juice could be stored at 1500 ppm sodium benzoate concentration in a good acceptable condition at ambient storage condition.

Multi-functional MXene quantum dots enhance the quality of perovskite polycrystalline films and charge transport for solar cells

Recently, two-dimensional (2D) transition metal carbides/nitrides (MXenes) find applications in perovskite solar cells (PSCs), due to their high conductivity, tunable electronic structures, and rich surface chemistry, etc. However, the integration of 2D MXenes into PSCs is limited by their large lateral sizes and relatively-small surface volume ratios, and the roles of MXenes in PSCs are still ambiguous. In this paper, zero-dimensional (0D) MXene quantum dots (MQDs) with an average size of 2.7 nm are obtained through clipping step by step combining a chemical etching and a hydrothermal reaction, which display rich terminals (i.e., -F, –OH, -O) and unique optical properties. The 0D MQDs incorporated into SnO2 electron transport layers (ETLs) of PSCs exhibit multifunction: 1) increasing the electrical conductivity of SnO2, 2) promoting better alignments of energy band positions at the perovskite/ETL interface, 3) improving the film quality of atop polycrystalline perovskite. Particularly, the MQDs not only tightly bond with the Sn atom for decreasing the defects of SnO2, but also interact with the Pb2+ of perovskite. As a result, the defect density of PSCs is significantly decreased from 5.21 × 1021 to 6.4 × 1020 cm-3, leading to enhanced charge transport and reduced nonradiative recombination. Furthermore, the power conversion efficiency (PCE) of PSCs is substantially improved from 17.44% to 21.63% using the MQDs-SnO2 hybrid ETL compared with the SnO2 ETL. Besides, the stability of the MQDs-SnO2-based PSC is greatly enhanced, with only ～4% degradation of the initial PCE after storage in ambient condition (25 °C, RH: 30-40%) for 1128 h, as compared to that of the reference device with a rapid degradation of ～60% of initial PCE after 460 h. And MQDs-SnO2-based PSC also presents higher thermal stability than SnO2-based device with continuous heating for 248 h at 85 °C. The unique MQDs exhibited in this work might also find other exciting applications such as light-emitting diodes, photodetectors, and fluorescent probes.

Solid-State White Light-Emitting Diodes Based on 3D-Printed CsPbX3-Resin Color Conversion Layers

Inorganic metal halide-based perovskites have tremendous potential for use in solid-state lighting due to their earth-abundant elements, solution processability, high photoluminescence quantum yield (PLQY), and tunable band gap energy and emission. However, the stability issue remains a challenge. Here, we report the use of a 3D printing technique to fabricate resin-perovskite color conversion layers to bridge the gap between material development and device applications. This not only simplified the fabrication process but also significantly improved the performance of the device. By using an economic 3D printer, color-emitting perovskite nanocrystals (green, yellow, and red) were mixed with highly transparent UV resin to obtain a thin color conversion layer. These 3D-printed color conversion layers retained above 80% of their original PLQY after 180 days of storage in ambient conditions, confirming their exceptional stability. Furthermore, we stacked the printed color conversion layers on top of the UV light-emitting diode chip, resulting in white lights with tunable correlated color temperatures, high color rendering indexes up to 94, color coordinates of (0.32, 0.33) close to the standard neutral white light, and high luminous efficacy of radiation up to 299 lm/W. As a result of this work, the adoption of solid-state lighting on a broader scale will be one step closer to reality.

Crystallinity Regulation and Defects Passivation for Efficient and Stable Perovskite Solar Cells Using Fully Conjugated Porous Aromatic Frameworks

AbstractFully conjugated porous aromatic frameworks (PAFs) have been constructed through Gilch reaction. The obtained PAFs have rigid conjugated backbones, high specific surface area, and excellent stability. The prepared PAF‐154 and PAF‐155 have been successfully applied in the perovskite solar cells (PSCs) by doping into the perovskite layer. The champion PSC devices afford a power conversion efficiency of 22.8 % and 22.4 %. It is found that the PAFs can be used as an efficient nucleation template, thus regulating the perovskite crystallinity. Meanwhile, PAFs can also passivate defects and promote carriers transporting in the perovskite film. By the comparative study with their linear counterpart, we unravel that the efficacy of PAFs is highly related to their porous structure and rigid fully conjugated networks. The unencapsulated devices with PAFs doping exhibit outstanding long‐term stability, retaining 80 % of their initial efficiencies after half‐year storage in ambient conditions.

Crystallinity Regulation and Defects Passivation for Efficient and Stable Perovskite Solar Cells Using Fully Conjugated Porous Aromatic Frameworks.

Fully conjugated porous aromatic frameworks (PAFs) have been constructed through Gilch reaction. The obtained PAFs have rigid conjugated backbones, high specific surface area, and excellent stability. The prepared PAF-154 and PAF-155 have been successfully applied in the perovskite solar cells (PSCs) by doping into the perovskite layer. The champion PSC devices afford a power conversion efficiency of 22.8% and 22.4%. It is found that the PAFs can be used as an efficient nucleation template, thus regulating the perovskite crystallinity. Meanwhile, PAFs can also passivate defects and promote carriers transporting in the perovskite film. By the comparative study with their linear counterpart, we unravel that the efficacy of PAFs is highly related to their porous structure and rigid fully conjugated networks. The unencapsulated devices with PAFs doping exhibit outstanding long-term stability, retaining 80% of their initial efficiencies after half-year storage in ambient conditions.