Buried Interface Modulation Using Self-Assembled Monolayer and Ionic Liquid Hybrids for High-Performance Perovskite and Perovskite/CuInGaSe Tandem Photovoltaics.

Effective modifications for the buried interface between self-assembled monolayers (SAMs) and perovskites are vital for the development of efficient, stable inverted perovskite solar cells (PSCs) and their tandem photovoltaics. Herein, an ionic-liquid-SAM hybrid strategy is developed to synergistically optimize the uniformity of SAMs and the crystallization of perovskites above. Specifically, an ionic liquid of 1-butyl-3-methyl-1H-imidazol-3-iumbis((trifluoromethyl)sulfonyl)amide (BMIMTFSI) is incorporated into the SAM solution, enabling reduced surface roughness, improved wettability, and a more evenly distributed surface potential of the SAM film.

Multidentate Polymer-Stabilized Buried Interface for Efficient Planar Perovskite Solar Cells.

Buried interface engineering is crucial to improve the performance and stability of perovskite solar cells (PSCs). Although coordination materials have been widely used for buried interface modification, they are generally engineered on one surface of the interface through monodentate or bidentate molecules. Here, we propose that a multidentate polymer, sodium alginate (SA), acts with both surfaces via numerous C═O groups to reinforce buried interfaces.

Construction and regulation of high active sites in montmorillonite composite catalyst for the removal of ofloxacin via persulfate activation.

In this study, ionic liquids (ILs) were used as organic modifiers by introducing montmorillonite nanolayers containing potential C and N active sites between the montmorillonite nanolayers. Organically modified montmorillonite (ILs-Mt-p) was further prepared by high-temperature pyrolysis under N and used for the removal of ofloxacin (OFL) by activated peroxymonosulfate (PMS). Combined with XPS and other characterization analyses, it was found that the catalyst materials prepared from different organic modifiers had similar surface functional groups and graphitized structures, but contained differences in the types and numbers of C and N active sites.

Printable High-Efficiency and Stable FAPbBr Perovskite Solar Cells for Multifunctional Building-Integrated Photovoltaics.

Perovskite solar cells (PSCs) show great promise for next-generation building-integrated photovoltaic (BIPV) applications because of their abundance of raw materials, adjustable transparency, and cost-effective printable processing. Owing to the complex perovskite nucleation and growth control, the fabrication of large-area perovskite films for high-performance printed PSCs is still under active investigation. Herein, the study proposes an intermediate-phase-transition-assisted one-step blade coating for an intrinsic transparent formamidinium lead bromide (FAPbBr ) perovskite film.

Protic Amine Carboxylic Acid Ionic Liquids Additives Regulate α-FAPbI Phase Transition for High Efficiency Perovskite Solar Cells.

The α-phase formamidinium lead tri-iodide (α-FAPbI ) has become the most promising photovoltaic absorber for perovskite solar cells (PSCs) due to its outstanding semiconductor properties and astonishing high efficiency. However, the incomplete crystallization and phase transition of α-FAPbI substantially undermine the performance and stability of PSCs. In this work, a series of the protic amine carboxylic acid ion liquids are introduced as the precursor additives to efficiently regulate the crystal growth and phase transition processes of α-FAPbI .

Low-Cost Fabrication of Efficient Perovskite Photovoltaics Using Low-Purity Lead Iodide via Powder Engineering.

Low cost is the eternal theme for any commercial production. Numerous efforts have been explored to realize low-cost, high-efficiency perovskite solar cells (PSCs), such as replacing the traditional spin-coating method with an economical printing strategy, simplifying the device structure, reducing the number of functional layers, . However, there are few reports on the use of low-cost precursors.

Low-Cost Hydroxyacid Potassium Synergists as an Efficient In Situ Defect Passivator for High Performance Tin-Oxide-Based Perovskite Solar Cells.

Perovskite solar cells (PSCs) based on SnO electron transport layers have attracted extensive research due to their compelling photovoltaic performance. Herein, we presented an in situ passivation of SnO with low-cost hydroxyacid potassium synergist during deposition to optimize the interface carrier extraction and transport for high power conversion efficiency (PCE) and stabilities of PSCs. The orbital overlap of the carboxyl oxygen with the Sn atom alongwith the homogenous nano-particle deposition effectively suppresses the interfacial defects and releases the internal residual strains in the perovskite.

Highly Efficient Self-Encapsulated Flexible Semitransparent Perovskite Solar Cells via Bifacial Cation Exchange.

Flexible semitransparent perovskite solar cells (ST-PSCs) have great potential for use in high-density energy systems, such as building or vehicle integrated photovoltaics, considering the great features of PSC devices, including high performance, light weight, thin-film processability, and high near-infrared transmittance. Despite numerous efforts toward achieving efficiency and flexibility in ST-PSCs, the realization of high-performance and operational stability in ST-PSCs still require further development. Herein, we demonstrated the development of highly efficient, stable, and flexible ST-PSCs using polyimide-integrated graphene electrodes via a lamination-assisted bifacial cation exchange strategy.

Highly Crystalline Graphene as the Atomic 2D Blanket of a Perovskite Absorber for Enhanced Photovoltaic Performance.

Perovskite solar cells (PSCs) have demonstrated enormous potential for next-generation low-cost photovoltaics. However, due to the intrinsically low bond energy of the perovskite lattice, the long-term stability is normally undermined by ion migration initiated by the electric field and atmospheric conditions. Therefore, ideal ion migration inhibition is important to achieve an enhanced stability of PSCs.

Mitigating the Internal Ion Migration of Organic-Inorganic Hybrid Perovskite by a Graphene Oxide Interlayer.

Organic-inorganic hybrid perovskite solar cells (PSCs) have attracted great research attention due to their outstanding optoelectronic properties. The low-temperature synthesizing process of organic-inorganic hybrid perovskites can provide a significant advantage of reducing the manufacturing cost of solar cells. However, at the same time, this also brings challenges to PSCs in the form of long-term stability.

Bandgap adjustment assisted preparation of >18% Cs FA PbI Br -based perovskite solar cells using a hybrid spraying process.

The preparation of Cs FA PbI Br -based perovskite by ultrasonic spraying has valuable application in the preparation of tandem solar cells on textured substrates due to its excellent stability and the advantages of large-area uniform preparation from the spraying technology. However, the bandgap of perovskite prepared by spraying method is difficult to adjust, and perovskites with a wide bandgap have the issue of phase instability. Here, we improved the crystallinity of the perovskite by simply controlling the post-annealing temperature.

All-vacuum deposited perovskite solar cells with glycine modified NiO hole-transport layers.

Organic-inorganic hybrid perovskite solar cells (PSCs) have attracted enormous research attention due to their high efficiency and low cost. However, most of the PSCs with high efficiencies still need expensive organic materials as their hole-transport layer (HTL). Obviously, the highly expensive materials go against the low-cost concept of advanced PSCs.

Differentiated Functions of Potassium Interface Passivation and Doping on Charge-Carrier Dynamics in Perovskite Solar Cells.

The inclusion of potassium in perovskite solar cells (PSCs) has been widely demonstrated to enhance the power conversion efficiency and eliminate the hysteresis effect. However, the effects of the locations K cations on the charge-carrier dynamics remain unknown with respect to achieving a more delicate passivation design for perovskite interfaces and bulk films. Herein, we employ the combined electrical and ultrafast dynamics analysis for the perovskite film to distinguish the effects of bulk doping and interfacial passivation of the potassium cation.

Printing strategies for scaling-up perovskite solar cells.

Photovoltaic technology offers a sustainable solution to the problem of soaring global energy demands. Recently, metal halide perovskite solar cells (PSCs) have attracted worldwide interest because of their high power conversion efficiency of 25.5% and great potential in becoming a disruptive technology in the photovoltaic industry.

Lead halide-templated crystallization of methylamine-free perovskite for efficient photovoltaic modules.

Upscaling efficient and stable perovskite layers is one of the most challenging issues in the commercialization of perovskite solar cells. Here, a lead halide-templated crystallization strategy is developed for printing formamidinium (FA)-cesium (Cs) lead triiodide perovskite films. High-quality large-area films are achieved through controlled nucleation and growth of a lead halide•-methyl-2-pyrrolidone adduct that can react in situ with embedded FAI/CsI to directly form α-phase perovskite, sidestepping the phase transformation from δ-phase.

Ink Engineering for Blade Coating FA-Dominated Perovskites in Ambient Air for Efficient Solar Cells and Modules.

To accelerate the commercial application of organic-inorganic hybrid perovskite solar cells (PSCs), it is necessary to develop simple and low-cost methods to prepare pinhole-free large-area perovskite films with high quality. A one-step blade coating method is regarded as a scalable technique. It is demonstrated that with the addition of ,'-dimethylpropyleneurea (DMPU) in an FA-dominated perovskite precursor, a large-area high-quality perovskite film can be obtained by blade coating, achieving improved photovoltaic performance, thermal stability, and storage stability.

Interface modification effect on the performance of CsFAPbIBr perovskite solar cells fabricated by evaporation/spray-coating method.

In this study, high quality CsFAPbIBr perovskite thin films were successfully fabricated by an evaporation/spray-coating hybrid deposition method. In this method, CsI and PbI were first deposited via thermal evaporation, and then FAI/FABr mixed solution was sprayed on the CsI/PbI substrate to form the CsFAPbIBr film. As confirmed by x-ray diffraction, scanning electron microscopy, and atomic force microscopy, a perovskite film with full surface coverage and small surface roughness was obtained.

3D Nitrogen-Doped Graphene Encapsulated Metallic Nickel-Iron Alloy Nanoparticles for Efficient Bifunctional Oxygen Electrocatalysis.

Invited for the cover of this issue is Liqiang Mai and co-workers at Wuhan University of Technology. The image depicts Ni Fe alloy nanoparticles encapsulated in N-doped graphene as an efficient bifunctional oxygen electrocatalyst toward rechargeable Zn-air batteries, which is expected to drive the electric vehicle. Read the full text of the article at 10.

A pressure-assisted annealing method for high quality CsPbBr film deposited by sequential thermal evaporation.

All-inorganic CsPbBr perovskite solar cells have triggered incredible interest owing to their superior stability, especially under high temperature conditions. Different from the organic-inorganic hybrid perovskites, inorganic CsPbBr perovskite always need a high annealing temperature for the formation of a cubic phase. Generally, the higher temperature (over 300 °C) and longer annealing time will promote the growth of CsPbBr, resulting in larger grain sizes and lower trap density in the crystals.

Solvent Engineering of a Dopant-Free Spiro-OMeTAD Hole-Transport Layer for Centimeter-Scale Perovskite Solar Cells with High Efficiency and Thermal Stability.

High efficiency and environmental stability are mandatory performance requirements for commercialization of perovskite solar cells (PSCs). Herein, efficient centimeter-scale PSCs with improved stability were achieved by incorporating an additive-free 2,2',7,7'-tetrakis[,-di(-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD) hole-transporting material (HTM) through simply substituting the usual chlorobenzene solvent with pentachloroethane (PC). A stabilized power conversion efficiency (PCE) of 16.

3D Nitrogen-Doped Graphene Encapsulated Metallic Nickel-Iron Alloy Nanoparticles for Efficient Bifunctional Oxygen Electrocatalysis.

It is extremely desirable to explore high-efficient, affordable and robust oxygen electrocatalysts toward rechargeable Zn-air batteries (ZABs). A 3D porous nitrogen-doped graphene encapsulated metallic Ni Fe alloy nanoparticles aerogel (Ni Fe-GA ) was constructed through a facile hydrothermal assembly and calcination process. Benefiting from 3D porous configuration with great accessibility, high electrical conductivity, abundant active sites, optimal nitrogen content and strong electronic interactions at the Ni Fe/N-doped graphene heterointerface, the obtained aerogel showed outstanding catalytic performance toward the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR).

Improved Performance of Planar Perovskite Solar Cells Using an Amino-Terminated Multifunctional Fullerene Derivative as the Passivation Layer.

Organic-inorganic metal-halide perovskite solar cells (PSCs) have been revolutionizing the photovoltaic (PV) community in the past decade. However, the trap states in TiO as the electron-transport layer seriously affect the device PV performance and stability. Here, we design and synthesize a fullerene derivative C60NH featuring an amino-terminated group.