Efficient and Stable Inverted Perovskite Solar Modules Enabled by Solid-Liquid Two-Step Film Formation

A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells.The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs.In this work,we adopted a solid-liquid two-step film formation technique,which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films.This method possesses the advantages of integrating vapor deposition and solution methods,which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform,large-area perovskite film.Furthermore,modification of the NiO_(x)/perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization.As a result,a large-area perovskite film possessing larger grains,fewer pinholes,and reduced defects could be achieved.The inverted PSM with an active area of 61.56 cm^(2)(10×10 cm^(2)substrate)achieved a champion power conversion efficiency of 20.56%and significantly improved stability.This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.

Deep original information preservation by applying in-situ film formation technology during coring

Accurately obtaining the original information of an in-situ rock via coring is a significant guiding step for exploring and developing deep oil and gas resources.It is difficult for traditional coring technology and equipment to preserve the original information in deep rocks.This study develops a technology for insitu substance-preserved(ISP),moisture-preserved(IMP),and light-preserved(ILP)coring.This technology stores the original information in real time by forming a solid sealing film on the in-situ sample during coring.This study designed the ISP-IMP-ILP-Coring process and tool.In addition,an ISP-IMP-ILPCoring process simulation system was developed.The effects of temperature,pressure,and film thickness on the quality of the in-situ film were investigated by performing in-situ film-forming simulation experiments.A solid sealing film with a thickness of 2-3 mm can be formed;it completely covers the core sample and has uniform thickness.The film maintains good ISP-IMP-ILP properties and can protect the core sample in the in-situ environment steadily.This study verifies the feasibility of“film formation during coring”technology and provides strong support for the engineering application of ISP-IMP-ILPCoring technology.

Crystal Structure during Film Formation

For evaporation-deposited Ti films, face-centred cubic structure was observed at the initial stage of film growth, then transited to the hexagonal close-packed structure during film growing (less than 50 nm thick). While. for ion-beam sputter-deposited films. the structure of films always kept the fcc structure during all stages of film formation. The structure of film at initial growth stages relates with the substrate. It is discussed that different film processes and different growth stages provide different thermodynamic condition of film formation and result in the different crystal structures of films during the film formation

Experimental research on air film formation behavior of air cushion belt conveyor with stable load

In this paper, the air film formation behavior of air cushion belt conveyor with stable load is studied. The air cushion field is analyzed by means of theoretical derivation, numerical simulation and experimental research. An intelligent experiment platform is developed. Three dimensional pressure distribution of air film and the air film thickness distribution along the conveyor belt in the width direction are obtained. The experimental result is analyzed by comparing with theoretical calculation and numerical simulation. The numerical and theoretical results are in good agreement with those obtained from experiments. The air film formation behavior pattern of air cushion belt conveyor with stable load is presented. The optimized film thickness and pore distribution are obtained based on the comprehensive energy consumption. This study provides a basis for the optimization design of air cushion belt conveyor.

Investigation of Formation Process of the Chrome-free Passivation Film of Electrodeposited Zinc

The feasibility was investigated to substitute chrome-free passivation treatment of electrodeposited zinc in a titanium bath for chromate passivation treatment. The formation mechanism of the chrome-free passivation film was further analyzed. The surface mor- phologies and the elemental compositions of the treated samples with varied immersion times were observed by scanning electron mi- croscopy （SEM） and determined by energy dispersion spectrometry （EDS）, respectively. The electrode potential of the sample surface was recorded in the film formation process. The changes of the electrode potential are in accordance with that of SEM and EDS of the sample surface. The results of X-ray photoelectron spectroscopy （XPS） show the chrome-free passivation film composed ofZnO, SiO2, TiO2, Zn4Si207（OH）2, and SrF2. The anode zinc dissolution and the local pH value increase due to the cathode hydrogen ion reduction process result in the formation of the chrome-free passivation film. The macro-images of the chrome-free passivation films formed on electrodeposited zinc show that the color of the film changes from blue to iridescence with the increase of the immersion times.

Droplet Manipulation and Crystallization Regulation in Inkjet-Printed Perovskite Film Formation

Emerging organic–inorganic metal halide perovskite materials have become the focus of the optoelectronics research community owing to their excellent photoelectric properties.Nevertheless,challenges still exist for transferring the lab-made devices to largearea industrial modules.Inkjet printing(IJP)technology provides a promising way to fill the gap because of its precise droplet control and uniform large-scale deposition functions.Hence,an in-depth understanding of inkjet-printed perovskite films in terms of droplet manipulation and crystallization regulation is critical for upscaling the perovskite devices to commercial usage.In this review,we give an overview of inkjet-printed high-quality perovskite films and provide guidelines on inkjet-printing large-scale highperformance perovskite devices.First,we analyze theories of droplet formation and perovskite nucleation/crystallization dynamics and then focus on summarizing the perovskite film-formation strategies via IJP,in the aspects of ink engineering,the printing process,and posttreatment.Furthermore,we review the recent advances of inkjet-printed perovskite films on optoelectronic devices,such as perovskite solar cells,perovskite light-emitting diodes,and perovskite photodetectors.Finally,we highlight the“Trilogy Strategies,”including ink engineering,printing process,and posttreatment for printing high-quality perovskite films.

Changing to Poly（rod-coil） Polymers： A Promising Way for an Optoelectronic Compound to Improve Its Film Formation

Good film formation is one of basic requirements for organic optoelectronic materials to achieve the capability for fabrication of large area devices. Small molecular optoelectronic compounds have a definite chemical structure and clear device performance, and thus are welcomed in the field. However, they are generally suffering from poor film formation, especially in a large area. For addressing it, this contribution proposes and demonstrates a strategy, that is, changing them into poly（rod-coil） polymers. With one optoelectronic compound [BDT（DTBT）2] and three poly（rod-coil） polymers （P1, P2, and P3） having different non-conjugated coil segments as examples, the work clearly shows that the change to poly（rod-coil） polymers keeps many basic optoelectronic properties of the refer- ence compound, including light absorption in solution, bandgap and frontier orbital energy levels, but suppresses strong intermolecular interactions and crystalline structure in film state. Further comparisons on film formation quality on glass and ITO glass illustrate that all the three polymers have a better film formation property than the reference compound.

Langmuir-Blodgett film formation of rare-earth metal di-,triphthalocyanine complexes and observation of their thin film by means of TEM and STM

Three different kinds of rare-earth metal phthalocyanine complexes(Pc_2LuH,Pc_3Gd_2, R_(12) Pc_3Dy_2)were synthesized.Their ultra-thin films were prepared by the Langmuir-Blodgett techni- que.Crystallites were observed in Langmuir film of Pc_3Gd_2 by means of transmission electron micros- copy.The limiting molecular areas of the phthalocyanine derivatives on pure water increased in the order mono-,di-and triphthalocyanine,implying that these phthalocyanine molecules are stacked with a face-to-face orientation and edge-on to the water surface.By using scanning tunneling mic- roscopy individual molecules of lutetium diphthalocyanine adsorbed on graphite surfaces were imaged for the first time.

SIMULTANEOUS POLYMERIZATION AND FORMATION OF POLYPHENYLACETYLENE FILMS BY RARE-EARTH COORDINATION CATALYSIS Ⅳ.KINETICS AND MECHANISM OF POLYMERIZATION

The CO_2 quenching method has been used for the first time to determine the active complex concen- tration in Nd(naph)_3-Al(i-Bu)_3 catalyst system for polymerization of phenylacetylene into polyphenylacetylene(PPA)films.The kinetics and mechanism of this polymerization have been investigated by CO_2 quenching and IR,UV analytical methods.The kinetic equation can be expressed as Rp=k[M][Cp],and the apparent activation energy is about 13.6 kJ/mol.There is self-termination of chain propagating.Models for formation of the active complex and polymerization mechanism are proposed.

Effect of Annealing Temperature on the Formation of Silicides and the Surface Morphologies of PtSi Films

The effect of annealing temperature on the formation of the PtSi phase. distribution of silicides and the surface morphologies of silicides films is investigated by XPS. AFM. It is shown that the phase sequences of the films change from Pt-Pt2Si-PtSi-Si to Pt+Pt2Si+PtSi-PtSi-Si or Pt+Pt2Si+PtSi-PtSi-st with an increase of annealing temperature and the reason for the formation of mixed layers is discussed.

Formation and Morphology of Anodic Oxide Films of Ti

The morphology and structure of the oxide films of Ti in H3PO4 were investigated by galvanos tatic anodization, SEM and XRD. The oxide film grew from some pores in the grooves to layered microdomains as increasing anodizing voltage. The crystallinity of the oxide films decreased with the increase of the concentration of the electrolyte. The model has been proposed for the growth of the oxide films by two steps, i.e. by uniform thickening and by local deposition.

EFFECT OF THE PHASE STRUCTURE EVOLUTION ON THE PROPERTIES OF FILMS FORMED FROM PBA/P(St-co-MMA) COMPOSITE LATEX

A group of heterogeneous latexes poly(butyl acrylate)/poly(styrene-co-methyl methacrylate)(PBA/P(St-co-MMA)) were prepared by a semi-continuous seeded emulsion polymerization process under monomer starved conditions.The glass transition temperature(T_g)and the mechanical properties of the film formed from the composite latex changed with the evolution of the particle morphology.A photon transmission method was used to monitor the phase structure evolution of films which were prepared from core-shell PBA/P(S...

Towards Solar-Driven Formation of Robust and Self-Healable Waterborne Polyurethane Containing Disulfide Bonds via in-situ Incorporation of 2D Titanium Carbide MXene

Waterborne polymers are vital for coating industry to reduce carbon emissions.However,formation of robust and self-healable films at ambient temperature remains a challenge owing to high energy cost of film formation process.This work reports a solar-driven film formation of waterborne polyurethanes(WPUs)containing disulfide bonds via in-situ incorporation of 2D titanium carbide(MXene)with ability to convert light to heat.Instead of directly mixed with WPUs,MXene is added to join the reaction with isocyanate-terminated pre-polymer before emulsification process.This approach not only prevents aggregation of MXene in water but stabilizes MXene against thermal degradation which is the key hurdle for mass production of MXene/WPU composites.More importantly,our results show that mechanical performance of WPU films under visible light(100 mW/cm^(2))is overwhelmingly competitive with that processed in oven.Furthermore,the existence of disulfide bonds in PU chains enables fast self-healing of micro-cracks under natural visible light which could vanish completely within 40 min.The fractured specimens were repaired under natural visible light for 2 h,and the self-healing efficiency of tensile strength and elongation at break reached over 94.00%.

An update on electrostatic powder coating for pharmaceuticals

Derived from dry powder coating of metals, electrostatic powder coating for pharmaceuticals is a technology for coating drug solid dosage forms. In this technology, coating powders, containing coating polymers, pigments, and other excipients, are directly sprayed onto the surface of the solid dosage forms through an electrostatic gun without using any organic solvent or water. The deposited coating powders are further cured to form a coating film. Electrostatic powder coating technology has many advantages compared to other pharmaceutical coating methods. It can eliminate the limitations caused by the organic solvent in solvent coating such as environmental issues and health problems. And electrostatic powder coating technology also surpasses aqueous coating due to its shorter processing time and less energy consumption, leading to a lower overall cost. Furthermore, the utilization of electrical attraction can promote the movement of coating powders towards the substrate, leading to an enhanced coating powder adhesion and coating efficiency, which make it more promising compared to other dry coating technologies. The objective of this review is to summarize the coating principles, apparatus, and formulations of different electrostatic powder coating technologies, giving their advantages and limitations and also analyzing the future application in the industry for each technology

Rechargeable solid-state Li-air batteries： a status report

The theoretical specific energy of lithium-air battery is as high as 3436 Wh.kg^-1, and the possible achieved value may reach 600-700 Wh.kg^-l, which enables this energy storage system as an important propulsion power sources for electric vehicles with the driving range of 500-800 km. Currently, Li-air batteries are facing main challenges at stability, efficiency, applicability and safety. In particular, from a practical view of point, the Li-air batteries should be operated directly in ambient air. Solid-state battery system is the best avenue to eventually solve these main issues. At the heart of the solid state, Li-air technology is the solid-state Li^＋-conducting ceramic material. Developing solid-state lithium-air batteries （SSLAB） can solve the problem of applicability fundamentally and circumvent the safety issues completely, and it is also an important avenue to improve the stability of the battery system. In this paper, we provide a systematical review of the progress in the cell construction, the regulation of the electrode/electrolyte interface, the cell assembly, the electrochemical performance and the mechanism for the SSLAB. In every section, the contributions of the recent research progress in the main challenges and the remained questions will be commented. Based on these reviews, we attempt to propose some alternative approaches for the next stage and suggest a development prospective for the SSLAB.