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Many organic molecules with various functional groups have been used to passivate the perovskite surface for improving the efficiency and stability of perovskite solar cell (PSCs). ...However, the intrinsic attributes of the passivation effect based on different chemical bonds are rarely studied. Here, we comparatively investigate the passivation effect among 12 types of functional groups on para-tert-butylbenzene for PSCs and find that the open circuit voltage (VOC) tends to increase with the chemical bonding strength between perovskite and these passivation additive molecules. Particularly, the para-tert-butylbenzoic acid (tB-COOH), with the extra intermolecular hydrogen bonding, can stabilize the surface passivation of perovskite films exceptionally well through formation of a crystalline interlayer with water-insoluble property and high melting point. As a result, the tB-COOH device achieves a champion power conversion efficiency (PCE) of 21.46%. More importantly, such devices, which were stored in ambient air with a relative humidity of ≃45%, can retain 88% of their initial performance after a testing period of more than 1 year (10,080 h). This work provides a case study to understand chemical bonding effects on passivation of perovskite.
Lead-acid batteries are a reliable and cost-effective uninterrupted power supply for cars, wheelchairs, and others. Recycling the spent lead-acid batteries has increased cost and could be a serious ...pollution issue after extensive use. It is important to exploit new-generation application to increase their value. In this article, we used a simple method for recycling spent lead-acid batteries for a useful lead iodide resource with a high purity of over 99% and a recycling yield of 93.1% and then fabricated multifunctional FAPbI3 perovskite diodes using recycled lead iodide (PbI2). The cost of recycled PbI2 based on lab-grade chemicals is estimated to be only 13.6% that of lab-grade PbI2, which undoubtedly greatly reduces the preparation cost of devices in the lab. The external quantum efficiencies of our perovskite diodes prepared with commercial and recycled PbI2 are 19.0 and 18.7%, respectively, which shows that the performance of the device prepared from recycled PbI2 is comparable to that of commercial lab-grade PbI2. Based on the expense of industrial-grade chemicals, the cost of recycled PbI2 is extrapolated to be 70.2% that of industrial-grade PbI2. Therefore, it can not only offer an approach to recycle hazardous solid waste but also save manufacturing cost of new-generation photoelectric devices, leading to earning additional value for lead waste.
Two‐step‐fabricated FAPbI3‐based perovskites have attracted increasing attention because of their excellent film quality and reproducibility. However, the underlying film formation mechanism remains ...mysterious. Here, the crystallization kinetics of a benchmark FAPbI3‐based perovskite film with sequential A‐site doping of Cs+ and GA+ is revealed by in situ X‐ray scattering and first‐principles calculations. Incorporating Cs+ in the first step induces an alternative pathway from δ‐CsPbI3 to perovskite α‐phase, which is energetically more favorable than the conventional pathways from PbI2. However, pinholes are formed due to the nonuniform nucleation with sparse δ‐CsPbI3 crystals. Fortunately, incorporating GA+ in the second step can not only promote the phase transition from δ‐CsPbI3 to the perovskite α‐phase, but also eliminate pinholes via Ostwald ripening and enhanced grain boundary migration, thus boosting efficiencies of perovskite solar cells over 23%. This work demonstrates the unprecedented advantage of the two‐step process over the one‐step process, allowing a precise control of the perovskite crystallization kinetics by decoupling the crystal nucleation and growth process.
The whole crystallization pathways and mechanism of two‐step‐fabricated perovskites are unveiled by in situ grazing‐incidence wide‐angle X‐ray scattering measurements and density functional theory calculations. Sequential A‐site doping of Cs+ and GA+ is found to alter the crystallization kinetics and improves the perovskite film morphology, giving rise to device efficiency as high as 23.5%.
Radix Isatidis, a commonly used traditional Chinese medicine, is also documented in “Dictionary of Chinese Ethnic Medicine” being as an ethnic herb clinically utilized by different nations in China ...such as Mongol, Uygur, and Dong et al. It has been reported to have a very strong efficacy on respiratory viruses, but to date the mechanism remains unknown. Similarly, it is unclear how different types of effective fractions of Radix Isatidis interact to exert antiviral effects. Aim of study: To reveal the underlying mechanisms for the inhibitory effects of three active fractions from Radix Isatidis, i.e. total alkaloids, lignans and organic acids, on respiratory syncytial virus when used alone or in combination. In addition, we investigated whether these three parts worked synergistically in vivo and in vitro. Materials and methods: A mouse model of RSV infection was constructed by intranasal infection, and the pathological changes of lung tissues in different parts were observed. The level changes of IFNβ and inflammatory cytokines in the mouse alveolar lavage fluid were detected by enzyme-linked immunosorbent assay (ELISA). The anti-RSV effects of different effective fractions were evaluated by the plaque reduction test. The mRNA and protein expressions of RIG-I, MDA-5, MAVS and IRF3 in RAW264.7 cells were detected by RT-PCR and Western blot respectively. Results: HE staining showed that Radix Isatidis extracts alone or in combination relieved virus-induced mouse lung lesions. Compared with individual drugs, the lung lesions were alleviated more significantly after treatment with the three fractions in combination. ELISA demonstrated that the expression levels of IFNβ and inflammatory cytokines were maintained balanced between antiviral and proinflammatory effects. The plaque reduction test indicated that the antiviral effect of combination treatment was much stronger than those of individual drugs. RT-qPCR and Western blot suggested that the mRNA and protein expression levels of key signaling molecules in the RIG-I and MDA5 pathways in mouse macrophages were down-regulated by different effective parts alone or in combination. Conclusions: The three effective fractions of Radix Isatidis have remarkable synergistic anti-RSV effects in vitro and in vivo, and total alkaloids and lignans show multi-target synergistic effects via the RIG-I and MDA5 signaling pathways.
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Poly(3,4‐ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) can be roll‐to‐roll deposited on the substrate facilely in the electronics, but its acidity and mismatched energy level limit the ...performance and stability. Herein, different metal salts are incorporated into PEDOT:PSS solution to prepare PEDOT:PSS‐AxOy (metal oxide) composite hole transport layer and it is found that the performance of inverted perovskite solar cells (PSCs) can be greatly enhanced. PSC using PEDOT:PSS‐MoOx has achieved much higher power conversion efficiency (PCE) (19.64%) than that of pristine PEDOT:PSS (12.19%). Two key factors are important for the performance enhancement. First, the increased surface free energy of PEDOT:PSS‐AxOy is beneficial for the formation of large crystal size and pinhole‐free film, leading to reduced nonradiative recombination. Second, the work function of PEDOT:PSS can be tuned to match the energy level of photoactive layer with small amount incorporation, which greatly enhances the photovoltage by a factor of 1.1. Besides, the devices based on PEDOT:PSS‐AxOy exhibit improved long‐term stability. Unencapsulated PSCs with PEDOT:PSS‐MoOx retain over 90% and 80% of their initial PCEs in N2 for 45 d and in ambient air for 20 d, respectively. The modified PEDOT:PSS solutions overcome the intrinsic imperfection and can be potentially employed for large‐scale production in the electronic devices.
Poly(3,4‐ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS)‐metal oxides have regulated wettability and work function and exhibit much higher performance in inverted perovskite solar cell. The best efficiency is based on PEDOT:PSS‐MoOx, with power conversion efficiency up to 19.64% for CH3NH3PbI3. Meanwhile, the PEDOT:PSS‐MoOx device maintains an efficiency of over 90% and 80% through 45 d follow‐up in N2 or 20 d in air, respectively.
FAPbI3 perovskite solar cells (PSCs) prepared by in-situ polymerization controlled growth (IPCG) strategy for crystal grains, deliver the power conversion efficiency (PCE) of 21% efficiency and ...retain their initial efficiency without decay after 104 days free of encapsulation in the ambient environment (RH=50±5%).
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•FAPbI3 perovskite film is deposited by in-situ polymerization controlled grain growth.•As-formed polymer stabilizes the black phase and blocks moisture penetration.•FAPbI3 solar cells retain initial efficiency after 104 days in ambient conditions.
The black perovskite (α-FAPbI3) tends to spontaneously transform into the yellow non-perovskite (δ-FAPbI3) under ambient conditions, which degrades the performance and stability of FAPbI3-based perovskite solar cells (PSCs). Herein, we applied an in-situ polymerization controlled growth (IPCG) strategy for crystal grain to suppress the α-to-δ phase conversion. Polymerization of 2-(Dimethylamino) ethyl methacrylate (DMAEMA) contained in the antisolvent created polymers (denoted as Poly(D)) which acted to simultaneously increase the perovskite grain size, passivate defects, stabilize the black phase, and block moisture penetration, thus greatly improving photovoltaic performance and stability. The resulting FAPbI3-based PSC (FTO/SnO2/Perovskite/Spiro-OMeTAD/Au) delivered a high power conversion efficiency (PCE) of ~ 21% (cf. ~ 16.0% PCE for the pristine FAPbI3 device). Further, the polymerization strategy delivers PSCs with remarkable stability, with 100% of the initial PCE performance being retained over 104 days under ambient conditions (room temperature, RH = 50 ± 5%) without encapsulation of the device.
Currently, photovoltaic/electroluminescent (PV/EL) perovskite bifunctional devices (PBDs) exhibit poor performance due to defects and interfacial misalignment of the energy band. Interfacial ...energy‐band engineering between the perovskite and hole‐transport layer (HTL) is introduced to reduce energy loss, through adding corrosion‐free 3,3′‐(2,7‐dibromo‐9H‐fluorene‐9,9‐diyl) bis(n,n‐dimethylpropan‐1‐amine) (FN‐Br) into a HTL free of lithium salt. This strategy can turn the n‐type surface of perovskite into p‐type and thus correct the misalignment to form a well‐defined N–I–P heterojunction. The tailored PBD achieves a high PV efficiency of up to 21.54% (certified 20.24%) and 4.3% EL external quantum efficiency. Free of destructive additives, the unencapsulated devices maintain >92% of their initial PV performance for 500 h at maximum power point under standard air mass 1.5G illumination. This strategy can serve as a general guideline to enhance PV and EL performance of perovskite devices while ensuring excellent stability.
A type of perovskite bifunctional device (PBD) with high photovoltaic (PV) and electroluminescence (EL) performance is developed. Interfacial energy‐band engineering between the perovskite and hole‐transport layer (HTL) is performed to turn the n‐type surface of the perovskite into p‐type and also correct the misalignment to form a well‐defined n–i–p heterojunction.
Integration of photovoltaic (PV) and electroluminescent (EL) functions and/or units in one device is attractive for new generation optoelectronic devices but it is challenging to achieve highly ...comprehensive efficiency. Herein, perovskite solar cells (PSCs) are fabricated, assisted by 3‐sulfopropyl methacrylate potassium salt (SPM) additive to tackle this issue. SPMs not only induce large grain size during the film formation but also produce a secondary phase of 2D K2PbI4 to passivate the grain boundaries (GBs). In addition, its sulfonic acid group and potassium ion can coordinate to lead ion and fill the interstitial defects, respectively. Thus, SPM reduces the defective states and suppresses nonradiative recombination loss. As a result, planar PSC delivers a power conversion efficiency of ≈22%, with a maximum open‐circuit voltage (Voc) of 1.20 V. The Voc is 94% of the radiative Voc limit (1.28 V), higher than the control device (Voc of 1.12 V). In addition, the reciprocity between PV and EL is also correlated to quantify the energy losses and understand the device physics. When operated as a light‐emitting diode, the maximum EL external quantum efficiency (EQEEL) is up to 12.2% (EQEEL of 10.7% under an injection current of short‐circuit photocurrent), thus leading to high‐performance PV/EL dual functions.
3‐sulfopropyl methacrylate potassium salt (SPM) has a multifunctional effect on the crystallization and passivation of perovskite film. The devices passivated by SPM achieve comprehensive efficiency with ≈22% photovoltaic (PV) efficiency and 10.7% electroluminescent (EL) quantum efficiency (under an injection current of short‐circuit photocurrent). The reciprocity between PV and EL is correlated.
•We advocate the molecular etiology of AS in which the inflammatory microenvironment induces vascularization at the site of bone lesions.•We believe that Tfhs are the prelude to the characteristic ...angiogenic bony outgrowth in AS known as syndesmophytes.•We speculate that devising therapeutics against angiogenesis or even working higher upstream to control Tfh blockage may be one of the selective options toward a halt in AS progression.
Ankylosing spondylitis (AS) is a chronic autoimmune arthritis that mainly affects spine joints. To date, the pathogenesis of AS remains unclear, although immune cells and innate immune response cytokines have been suggested to be crucial players. Methods: By adopting a single-cell RNA sequencing approach in the AS cynomolgus model, we profiled and characterized PBMC proportions along disease progression. Results: Here, our primary focus was on the activation of an immune cascade-initiating lymphocyte subtype known as CD4+CXCR5+ T follicular helper (Tfh) cells. These Tfhs demonstrated a localized residence in AS bone lesion as an ectopic lymphoid structure. Moreover, Tfhs would serve as an upstream initiator for a pro-angiogenic cascade. Then, an expansion in CD14+ monocytes and DC cells subsets resulted in enhanced expression of angiogenesis genes in these AS cynomolgus monkeys. With a confirmed higher abundance of TNF-α accompanying H-type vascular invasion in the osteophytic region, pronounced expansion of Tfhs at such lesion site signaling for monocytes and DCs intrusion is considered as the prelude to the characteristic angiogenic bony outgrowth in AS known as syndesmophytes. Conclusions: We explored the intimate relationship between local inflammation and bone formation in AS from the perspective of nascent vascularisation. Hence, our study lays the foundation for elucidating a unified AS pathogenesis through the immune-angiogenesis-osteogenesis axis.
