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Inorganic perovskite absorbers are promising candidates for next-generation photovoltaics due to their good thermal and light stabilities. Halide-mixed CsPbIxBr3−x reach a compromise between its structural tolerance and absorption edge, yet the power conversion efficiencies (PCEs) of the asfabricated cells can be considerably limited by the nonideal quality of solution-processed films. Here we demonstrated a fumigation strategy on colloidal perovskite films using dual-O-donor ethyl acetate (EA). By in-situ monitoring this stage with grazing-incidence wide-angle X-ray scattering technology, we reveal that EA fumigation would impose ripening barrier on colloidal inorganic perovskites and hence slow down the nucleation rate, leading to an intermediate state for processing high-crystallinity and oriented perovskite films with improved photophysical properties. An optimized PCE of 16.6% was finally yielded upon wide-bandgap (1.9 eV) perovskite absorber.

Perovskite solar cells (PSCs) have been attracting increasing attention in recent years because of their exceptional high efficiency with incredible developments. However, the poor contact between the hole transport layer (HTL) and perovskite layer still limits the further development of power conversion efficiency (PCE) for inverted solar cells, particularly for inorganic HTL based devices. Herein, potassium salt (KI, KSCN and KNO3) modified nickel oxides are selected as HTLs to improve the photovoltaic performance of an inverted device. We found that all potassium salts play positive roles in optimizing the photovoltaic parameters. Through the modification of potassium salts, higher charge recombination impedance and strong photoluminescence quenching were achieved, which means retarded carrier nonradiative recombination and quick charge transfer at the interface. Besides, KI modified NiOX could improve the perovskite film coverage and reduce trap densities. Thus, the champion device based on a KI modified NiOX film attained a PCE of 20.10% with an enhanced fill factor of 0.812. The findings demonstrate that potassium doping is an effective route to improve the performance of inverted planar PSCs.

Metal halide perovskites (MHP) are an emerging class of semiconducting materials with superior optoelectronic properties, which have achieved notable success in photoelectric device applications. As a classical technique in the semiconductor industry, epitaxy has indeed advanced the perovskite technology in the recent years by enabling the material combinations with a coherent interfacial lattice as well as combined complementary functionalities, which are not available in the single-phase constituents. In this review, we start with the basic principles and chemical techniques for the epitaxial growth of MHP-based materials. We summarize the epitaxial structures of perovskite solids, which are categorized by the combined materials and compare their performance in photoelectric devices including solar cells, photodetectors, and light-emitting diodes (LEDs). The impact of lattice strain and band structure at the substrate/perovskite interface, which can affect the energy conversion process, are then discussed after the epitaxial cases. We finally outline the future directions for perovskite epitaxy, targeting the in situ monitoring of the surface atomic kinetics during the growth, precise interfacial structure characterization, and the upscaling fabrications, which might further benefit the performance and application of perovskite-based devices.

Organic–inorganic hybrid perovskite materials have attracted enormous attention owing to their extraordinary progress in both power conversion efficiency and stability. However, nonradiative carrier recombination occurring in the perovskite films and interface hinders its commercial viability as the next-generation photovoltaics. Doping with metal cations has been demonstrated to be efficacious for controlling charge transport and reducing charge recombination for perovskite solar cells. Herein, we report the homogeneous doping of entire perovskite solar cells by alkali cations via a dopant diffusion strategy from the hole transport layer. It was found that Rb+ ions enhanced the conductivity and optimized the energy level alignment. The diffused Rb+ ions within the perovskite layer could further reach the bulk films with modulated electronic states. The power conversion efficiency of the perovskite solar cell based on 1.0% Rb+-doped NiOx boosts to 21.80% with a high fill factor of 0.824. Unencapsulated Rb+-doped NiOx photovoltaic devices maintained 93.3% of their initial efficiency after storage in air for 1200 h.

The efficiency, stability, and scalability of perovskite devices still require further enhancement for real-world application. Defect passivation has been recognized as one prominent strategy that ...

Cesium lead halide perovskites are promising alternatives as light-absorbing materials for achieving perovskite solar cells with excellent thermal stability, but their inferior power conversion efficiency (PCE) and ambient instability are impeding their application. In this work, we show that liquid water can assist the formation of CsPbI2Br perovskites under the synergetic adsorption of H2O and dimethylsulfoxide (DMSO), which enabled uniform, [100] oriented CsPbI2Br films with a grain size up to 4.4 μm. It was found that a suitable amount of H2O helps desorb the DMSO molecules, and thus favours the formation of a cubic perovskite phase from DMSO complexed intermediates. Perovskite solar cells based on our strategy delivered an optimized PCE of 16.47% with a high open-voltage of 1.33 V, as well as good device stability against humidity, light and heat.

Cesium-based all-inorganic perovskite absorbers have attracted increasing attention due to their superior thermal stability, compared to their organic–inorganic counterparts. Up to now, it is a challenge to fabricate high-efficiency all-inorganic perovskite solar cells (PSCs) with low defect densities. Herein, we used bivalent metal chloride salts (SrCl2 and NiCl2) to optimize CsPbI2Br films. The experimental results indicate that this method could deliver high-quality films with improved electronic property. As a result, the champion device based on the 0.01 M SrCl2–doped CsPbI2Br film achieved a power conversion efficiency (PCE) of 16.07% with a high open voltage (VOC) of 1,322 mV, which is about 18% higher than that of the pristine device.

Pressurizer surge line is one of the key equipments of nuclear power plants. The thermal stratification due to the intersection of hot and cold fluids inside the pressurizer surge line may affect the safe operation of nuclear power plant. In order to investigate the stress distribution and fatigue characteristics of surge line subjected to long-term thermal stratified loadings, a mechanical model of the surge line was established. And then, according to different temperature distribution assumptions, thermal stress analysis and fatigue assessment were conducted. The results show that the maximum stress appears under the load condition with maximum temperature difference, and finer temperature distribution can obtain more accurate stress and displacement results. The maximum value of fatigue cumulative coefficient appears at the junction of straight pipe and elbow with large temperature difference.

Organic–inorganic hybrid perovskite solar cells (PSCs) have been rapidly evolving as a promising candidate for next-generation photovoltaic technologies. P-type organics or polymers are generally used as hole transport materials (HTMs), which are expensive and non-sustainable for long-term applications. Herein, we demonstrate an inorganic Ni–Co–O hole conductor that displayed fast hole extraction and transport by the presence of gap states and relative high hole conductivity. Detailed structural inspection reveals that Co3+ and Ni2+ ions would reform into Co2+ and Ni3+ sites with the incorporation of Co, which contributes to greatly enhanced hole concentration. Inverted heterojunction devices based on NiCoOx hole transport layers yielded a maximum power conversion efficiency (PCE) of 20.03%, with 16.9% improvement compared with those based on NiOx layers (17.14%). This novel HTM with a facile synthesis process provides a new strategy for designing efficient carrier transport materials such that efficient charge collection and transport are achieved.

To compare the curative effect between bloodletting at tip of ear with different amounts combined with western medication and western medication alone for early-stage stye.A total of 108 patients with early-stage stye were randomly divided into a 50 μL group (36 cases, 4 cases dropped off), a 100 μL group (36 cases, 2 cases dropped off) and a western medication group (36 cases, 5 cases dropped off). The patients in the western medication group were treated with levofloxacin eye drops and levofloxacin hydrochloride eye gel. Based on the treatment of the western medication group, the patients in the 50 μL group were treated with 50 μL bloodletting (about 3 drops) at tip of ear while the patients in the 100 μL group were treated with 100 μL bloodletting (about 6 drops) at tip of ear; the bloodletting was given once a day for 3 days. After treatment, the changes of visual analogue scale (VAS) and clinical effect were observed, and the patients were followed up by telephone on the 8th day.After treatment, the VAS score in each group was reduced (Based on the conventional western medication treatment, bloodletting at tip of ear can significantly reduce the pain of stye, and the effect of 100 μL bleeding is better than 50 μL.

As one of the most promising light-harvesting materials, perovskites have drawn tremendous attention for their unique advantages, such as high efficiency, low cost and facile fabrication compared with other photovoltaic materials. Nevertheless, poor moisture tolerance of the perovskites greatly hampers the operation of such devices and hinders their commercialization. Herein, we demonstrate a facile dipping treatment using sulfur-oleylamine solution for surface atomic modulation of perovskite films. Oleylammonium polysulfides (OPs) would be self-assembled on the etched perovskite film as an ultrathin outer layer. This layer could passivate the surface chemical activity of the outer perovskite layers. Moreover, the hydrophobic OPs significantly enhance moisture stability of such devices. As a result, the obtained device without encapsulation retains more than 70% of its initial power conversion efficiency (PCE) after 14 days of exposure to a relative humidity of 40 ± 10%.

The insertion of organic spacers into halide perovskite slabs has offered a trade-off between the efficiency and stability of perovskite solar cells (PSCs). The layered structure of diammonium-intercalated cesium lead halide perovskites is virtually unexplored, in contrast to several works on the monoammonium system. In this report, we find that perovskite with 1,4-butanediammonium (BDA) and cesium cations can only form n = 1 and n = 2 layered isologues defined by the chemical formula of (BDA)Csn-1Pbn(I0.7Br0.3)3n+1, while the n = 3-4 ones will self-construct into unique heterostructures comprising separated quantum wells (QWs; n = 1-2) and 3D (n = ∞) perovskites. We highlight that the 2D/3D heterostructures show a structural resemblance to that of bulk heterojunction in organics, thus improving the charge separation and transport more than surface passivation. Solar cells based on the (BDA)Cs3Pb4I9.1Br3.9 (n = 4) absorbing layer delivered a power conversion efficiency (PCE) reaching 9.49% with ideal light and thermal stability.

A highly transparent NiO layer was prepared by a solution processing method with nickel(II) 2-ethylhexanoate in non-polar solvent and utilized as HTM in perovskite solar cells. Excellent optical transmittance and the matched energy level lead to the enhanced power conversion efficiency (PCE, 18.15 %) than that of conventional sol-gel-processed NiO-based device (12.98 %).

Background: This study evaluated the effectiveness and safety of bloodletting (BL) at ear-apex (EX-HN6) as an adjunctive therapy to eye drops for stye. Methods: This study systematically searched electronic databases from inception to March 1, 2020 in PUBMED, EMBASE, Cochrane Library, China National Knowledge Infrastructure, Chinese Scientific Journals Full-text Database, and WanFang Database. All potential randomized controlled trials (RCTs) investigating the effectiveness and safety of BL at EX-HN6 as an adjunctive therapy to eye drops for stye were included in this study. Study quality of all included studies was assessed by Cochrane Risk of Bias Assessment Tool. RevMan 5.3 software was used for statistical analysis and meta-analysis performance. Results: A total of 11 RCTs, involving 1718 subjects, were included in this study. Results showed that BL at EX-HN6 as an adjunctive therapy to eye drops was superior to the eye drops alone in enhancing total effectiveness rate (risk ratio [RR] 1.21, 95% confidence intervals [CIs] [1.11, 1.32], I2 = 79%), and total cure rate (RR 1.28, 95% CIs [1.14, 1.43], I2 = 69%). After removing two studies, results of subgroup analysis still showed significant improvements in total effectiveness rate (RR 1.13, 95% CIs [1.08, 1.18], I2 = 0%), and total cure rate (RR 1.16, 95% CIs [1.08, 1.24], I2 = 0%). No data of adverse reactions was reported in primary trials, thus, this study did not analyze adverse reactions of BL at EX-HN6 as an adjunctive therapy to eye drops for stye. Conclusion: BL at EX-HN6 as an adjunctive therapy to eye drops may benefit stye. However, high-quality RCTs addressing on this issue is still needed to warrant the findings of this study.

A hybrid light/ToF-SIMS system was used to analyze the dynamic chemical changes of perovskite CH3NH3PbI3 films under light illumination, in order to reveal the mechanism of light instability for perovskite materials. Real-time material degradation and quasi-reversible iodine migration were successfully observed.

Organometallic halide perovskite solar cells (PSCs) are rapidly evolving as the promising photovoltaic technologies with high record efficiency over 24%. The inorganic p-type semiconductor NiOx is extensively used as important hole transport layers for the realization of stable and hysteresis-free solar cells due to their good electronic properties, facile fabrication, and excellent chemical endurance. However, the critical issues of NiOx films including poor intrinsic conductivity and mismatched band alignment limit further improvement of the device performance. Herein, it is demonstrated that a versatile alkaline earth metal (Mg, Ca, Sr, and Ba) doping strategy can effectively engineer the electronic properties of NiOx contacts in inverted planar PSCs. Alkaline earth metal doping can deepen valence band maximum and enhance the hole conductivity of NiOx films, which better aligns the energy band in solar cells. The champion device based on Sr-doped NiOx films attains a power conversion efficiency of 19.49% with a high open-circuit voltage (VOC) of 1.14 V for NiOx-based CH3NH3PbI3 devices. The resulted device shows negligible hysteresis and high stability as well. This finding provides a systematic doping strategy to further improve the performance of inverted planar PSCs.

A gradient heterosturcture is one of the basic methods to control the charge flow in perovskite solar cells (PSCs). However, a classical route for gradient heterosturctures is based on the diffusion technique, in which the guest ions gradually diffuse into the films from a concentrated source of dopants. The gradient heterosturcture is only accessible to the top side, and may be time consuming and costly. Here, the "intolerant" n-type heteroatoms (Sb3+ , In3+ ) with mismatched cation sizes and charge states can spontaneously enrich two sides of perovskite thin films. The dopants at specific sides can be extracted by a typical hole-transport layer. Theoretical calculations and experimental observations both indicate that the optimized charge management can be attributed to the tailored band structure and interfacial electronic hybridization, which promote charge separation and collection. The strategy enables the fabrication of PSCs with a spontaneous graded heterojunction showing high efficiency. A champion device based on Sb3+ doped film shows a stabilized power-conversion efficiency of 21.04% with a high fill factor of 0.84 and small hysteresis.

In order to consider high-order effects on the actual limit state function, a new response surface method is proposed for structural reliability analysis by the use of high-order approximation concept in this study. Hermite polynomials are used to determine the highest orders of input random variables, and the sampling points for the determination of highest orders are located on Gaussian points of Gauss-Hermite integration. The cross terms between two random variables, only in case that their corresponding percent contributions to the total variation of limit state function are significant, will be added to the response surface function to improve the approximation accuracy. As a result, significant reduction in computational cost is achieved with this strategy. Due to the addition of cross terms, the additional sampling points, laid on two-dimensional Gaussian points off axis on the plane of two significant variables, are required to determine the coefficients of the approximated limit state function. All available sampling points are employed to construct the final response surface function. Then, Monte Carlo Simulation is carried out on the final approximation response surface function to estimate the failure probability. Due to the use of high order polynomial, the proposed method is more accurate than the traditional second-order or linear response surface method. It also provides much more efficient solutions than the available high-order response surface method with less loss in accuracy. The efficiency and the accuracy of the proposed method compared with those of various response surface methods available are illustrated by five numerical examples.

Classical Swine Fever Virus (CSFV) E2 protein eukaryotic expression plasmid pVAXE2 was constructed. The plasmid pVAXE2 was transformed into Salmonella choleraesuis C500 (S. C500) attenuated vaccine strain by electroporation to generate Salmonella choleraesuis engineering strain S. C500/pVAXE2. The characterization of S. C500/pVAXE2 in morphology, growth, biochemistry and serology indicated that it retained the same properties as its original strain S. C500 with exception of kanamycin resistance originated from the plasmid pVAXE2. The plasmid stable in the bacteria after 15 passages. Kunming mice and rabbits were vaccinated three times at two weeks interval with S. C500/pVAXE2 in oral and intramuscular routes at the dosage of 1 x 10(8) CFU for mice and 2 x 10(9) CFU for rabbits each time. The specific antibody response against CSFV and Salmonella choleraesuis was detected by ELISA. Two weeks after the third boost the immunized rabbits were challenged with 20 ID50 of hog cholera lapinized virus (HCLV), followed by a virulent strain of Salmonella choleraesuis two week later than HCLV challenge. The results showed that all immunized mice and rabbits produced significant antibodies against CSFV and Salmonella choleraesuis, and the immunized rabbits demonstrated the effective protection against the challenge of HCLV and virulent Salmonella choleraesuis. These results indicated the potential of developing multiplex swine DNA vaccine by using this bacteria as the vector.