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Abstract Solid‐state batteries represent the future of energy storage technology, offering improved safety and energy density. Garnet‐type Li7La3Zr2O12 (LLZO) solid‐state electrolytes‐based solid‐state lithium batteries (SSLBs) stand out for their appealing material properties and chemical stability. Yet, their successful deployment depends on conquering interfacial challenges. This review article primarily focuses on the advancement of interfacial engineering for LLZO‐based SSLBs. We commence with a concise introduction to solid‐state electrolytes and a discussion of the challenges tied to interfacial properties in LLZO‐based SSLBs. We deeply explore the correlations between structure and properties and the design principles vital for achieving an ideal electrode/electrolyte interface. Subsequently, we delve into the latest advancements and strategies dedicated to overcoming these challenges, with designated sections on cathode and anode interface design. In the end, we share our insights into the advancements and opportunities for interface design in realizing the full potential of LLZO‐based SSLBs, ultimately contributing to the development of safe and high‐performance energy storage solutions.

Solid‐state batteries represent the future of energy storage technology, offering improved safety and energy density. Garnet‐type Li7La3Zr2O12 (LLZO) solid‐state electrolytes‐based solid‐state lithium batteries (SSLBs) stand out for their appealing material properties and chemical stability. Yet, their successful deployment depends on conquering interfacial challenges. This review article primarily focuses on the advancement of interfacial engineering for LLZO‐based SSLBs. We commence with a concise introduction to solid‐state electrolytes and a discussion of the challenges tied to interfacial properties in LLZO‐based SSLBs. We deeply explore the correlations between structure and properties and the design principles vital for achieving an ideal electrode/electrolyte interface. Subsequently, we delve into the latest advancements and strategies dedicated to overcoming these challenges, with designated sections on cathode and anode interface design. In the end, we share our insights into the advancements and opportunities for interface design in realizing the full potential of LLZO‐based SSLBs, ultimately contributing to the development of safe and high‐performance energy storage solutions. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries feature high safety, low cost, and relatively high energy density; however, their cycle life is hindered by severe Zn dendrite formation and water‐induced parasitic reactions. Herein, a porous polyaniline (PANI) interfacial layer is developed on the surface of Zn metal anode to regulate the transport and deposition of Zn2+, achieving an ultra‐stable and highly reversible Zn anode. Specifically, the abundant polar groups (NH and N) in PANI have a strong attraction to H2O, which can trap and immobilize H2O molecules around Zn2+. Moreover, the protective layer regulates ion flux and deposition behavior of Zn2+ through the ion confinement effect. Consequently, the Zn@PANI anode exhibits improved reversible plating/stripping behavior with a low nucleation overpotential (37.9 mV) at 2.0 mA cm‐2 compared to that of bare Zn anode. The MnO2//Zn@PANI cell demonstrates a high capacity retention of 94.3% after 1000 cycles at 1.0 A g−1. This study lays the foundation for accessible interface engineering and in‐depth mechanistic analysis of Zn anode. [ABSTRACT FROM AUTHOR]

Colloidal quantum dots (QDs) without toxic heavy metals are promising candidates for exploiting the next‐generation solar cells by virtue of their numerous merits, including solution processability, facile bandgap tunability and wide absorption spectrum range. However, a large number of photo‐generated carriers are captured by their inherent defects instead of effective dissociation, which immensely hinders the device performance. Herein, the silver‐gold‐selenide (AgAuSe) QDs with well‐treated defect states were firstly employed as the photo‐absorber of active layer to construct environment‐friendly QD solar cells, in which an inverted AgAuSe QD solar cell composed of ITO/SnO2/AgAuSe/Au/PCE10:BTP‐4Cl/MoO3/Al was fabricated. Thereinto, after the n‐i‐p infrastructure of SnO2/QD/PCE10 being determined, a layer of Au nanoparticles (NPs) was introduced into the QD/PCE10 interface to modulate the energy‐level alignment of the device. This interfacial modification significantly improved the device performance by increasing the open‐circuit voltage and fill factor, which was different from the absorption enhancement mechanism originated from the plasmonic effects of Au NPs. Lastly, the PCE10 layer was blended with BTP‐4Cl to increase the short‐circuit current density of device through its complementary absorption to AgAuSe QD, which further increased the power conversion efficiency up to 4.14% with the synergistic effect of Au NPs layer. [ABSTRACT FROM AUTHOR]

Recently, organic solar cells (OSCs) have received rapid boosts in the power conversion efficiency (PCE), due to progresses in materials and device engineering. Several groups have reported champion PCEs over 19% in single‐junction, ternary, and tandem OSCs. In addition to the concentrated focus on the new design of OSC active materials, buffer layer materials, used for the interface layer providing the functionalities of interface charge transport and collection in OSCs, are of critical importance for the optimization of PCE. Compared with the electron transport layers (ETL), the hole transport layers (HTLs) have received less attention and are still dominated by the commercial material poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), which has limitations for the efficiency and OSC device stability enhancement. In this Review, the recent progress in HTL materials, including the modifications for PEDOT:PSS, alternative HTL materials based on polymers and inorganic oxide materials, etc, is summarized. This review also provides a summative prospect aiming to help scientists apprehend the current possibilities and challenges in this field. [ABSTRACT FROM AUTHOR]

The under‐coordinated defects within perovskite and its relevant interfaces always attract and trap the free carriers via the electrostatic force, significantly limiting the charge extraction efficiency and the intrinsic stability of perovskite solar cells (PSCs). Herein, self‐diffusion interfacial doping by using ionic potassium L‐aspartate (PL‐A) is first reported to restrain the carrier trap induced recombination via the reconstruction of energy level structure at SnO2/perovskite interface in conventional n‐i‐p structured PSCs. Experiments and theories are consistent with the PL‐A anions that can remain at the SnO2 surface due to strong chemical adsorption. During the spin‐coating of the perovskite film, the cations gradually diffuse into perovskite and endow an n‐doping effect, which provides higher force and a better energy level alignment for the carrier transport. As a result, they obtained 23.74% power conversion efficiency for the PL‐A modified small‐area devices, with dramatically improved open‐circuit voltage of 1.19 V. The corresponding large‐area devices (1.05 cm2) achieved an efficiency of 22.23%. Furthermore, the modified devices exhibited negligible hysteresis and enhanced ambient air stability exceeding 1500 h. [ABSTRACT FROM AUTHOR]

Ion defects at surface and grain boundaries (GBs) of perovskite films are paramount factors that influence the power conversion efficiency (PCE) of organic–inorganic hybrid perovskite solar cells (PSCs). Various methods have been proposed to solve the problems, but it still remains a great challenge because of the sophisticated and multiplicity of these defects. Herein, a modification method is developed that all‐inorganic low‐dimensional cesium copper halide nanocrystals (Cs3Cu2I5 NCs) are introduced to reduce the ionic defects of perovskite films at the surface and GBs. The champion device modified by Cs3Cu2I5 NCs exhibits remarkable promotion of PCE from 19.88% to 22.03% and fill factor from 74.09% to 82.21%. The results show that the solid‐state interdiffusion process occurs between the perovskite films and Cs3Cu2I5 NCs, which can improve the crystallinity, reduce interfacial recombination loss, and enhance the interfacial carrier transport in PSCs. Especially, the element distribution of Cs3Cu2I5 NCs in perovskite films affects the effectiveness of ionic defects passivation in the perovskite lattice. The PSCs device retains 91.6% of its initial PCE after 504 h under high moisture conditions. This work demonstrates an interfacial engineering strategy using the characteristic perovskite NCs, which provides a passivation method to achieve the high‐performance PSCs. [ABSTRACT FROM AUTHOR]

The defects in organic–inorganic halide perovskite films are detrimental to device efficiency and the stability of perovskite solar cells (PSCs). Interfacial modification is a universal way to passivate defects and improve device performance. However, the effect of terminal groups in non‐fullerene acceptors (NFAs) on interfacial passivation in PSCs is still under investigation. Here, we demonstrate that ending groups of NFAs play an important role in interfacial modification. By comparing four different non‐fullerene molecules with different ending groups (ITCC, ITIC, IT‐M, IT‐4F) applied as passivation layer, we found that devices with ITCC showed better performance, which was attributed to the assistance of the S atom in the ending group of ITCC enhancing adsorption to the perovskite surface compared to the ITIC case, leading to a tighter contact with the perovskite layer and better charge transfer. As a result, in FA0.85MA0.15Pb(I0.85Br0.15)3 based PSCs, we achieved a power conversion efficiency of 21.21% and an open‐circuit voltage of 1.15 V. Meanwhile, the device with ITCC showed extraordinary stability, maintaining more than 90% initial efficiency after 2000 h. The findings of this work could provide deeper insights into designing novel passivation materials at molecular scale for high efficiency and stable PSCs. [ABSTRACT FROM AUTHOR]

Graphene/semiconductor heterojunction based solar cell is realized as a promising candidate for high‐efficiency solar cells. However, the interface between graphene and the semiconductor should be further explored to enhance the performance of the solar cell. As graphene is impermeable to water and gases, encapsulating hole conducting organic material poly(3,4‐ethylene‐dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) at the interface is possible and can improve the surface passivation, p‐dope graphene, increase the barrier height, and speed up the transfer of carriers. Herein, a novel graphene/PEDOT:PSS/GaInP organic/inorganic Schottky heterojunction solar cell is designed and assembled via interfacial chemical modification. The cell exhibits an open‐circuit voltage (Voc) of 0.90 V under AM1.5 illumination, while the counterpart solar cell without PEDOT:PSS interlayer only gives a Voc of 0.49 V. In comparison with the PEDOT:PSS interlayer, indium tin oxide (ITO) film shows little effect on the improvement of Voc. The Voc of graphene/ITO/GaInP and ITO/PEDOT:PSS/GaInP solar cells is 0.11 and 0.37 V, respectively. As a result, the power conversion efficiency (PCE) of the Schottky junction solar cell with an interlayer reaches up to 4.55%, more than seven times that obtained without interlayer. The work has proven that integrating graphene/semiconductor heterostructure solar cells with organic conductive materials in the interface can achieve high PCE. [ABSTRACT FROM AUTHOR]

Inorganic cesium lead halide perovskite solar cells are promising candidates for next‐generation photovoltaic applications. However, their phase instability and relatively low efficiency hinder their commercialization. Herein, hydrophobic organic ammonium halides (Cl, Br, and I) are rationally used for the modification of inorganic CsPb(I0.75Br0.25)3 perovskite solar cells. Benefiting from their passivation effects and hydrophobic long alkyl chain, the modified devices exhibit enhanced efficiency and stability. Among them, the hexadecyltrimethylammonium chloride (CTAC)‐modified device shows the best performance with a power conversion efficiency (PCE) of 18.05%. Furthermore, a gradient triple anion inorganic perovskite CsPb(I0.75Br0.25)3−xClx layer is formed in situ during the CTAC modification, which demonstrates better phase stability than CsPb(I0.75Br0.25)3. As a result, the modified device also shows excellent stability, maintaining 94% of the initial efficiency after 35 days in N2 atmosphere. [ABSTRACT FROM AUTHOR]

Abstract In biohydrometallurgical processes, a mineral exhibits different oxidation phases due to the system's heterogeneity, especially in heap leach pads. Oxidation chemically modifies the mineral surface altering its interface, and thereby affecting the bacteria-mineral interaction, mineral reactivity and leaching velocity. Given that the mineral can be found in different oxidation states in heap bioleaching processes, three oxidation conditions of FeS 2, in which iron and/or sulfur related compounds are formed on the mineral surface were assayed. This paper studies the interaction between the modified surface of a sulfide mineral, FeS 2 , and 0 K culture medium, typically used in biomining processes. Chemical and electrochemical changes on surfaces were characterized by subjecting them to weathering in an acidic culture medium (pH 1.8), without applying potential or current. The chemical species formed were identified by Raman spectroscopy. The modified pyrite surfaces showed significant interfacial transformations upon immersion in the culture medium, and the formation of passive chemical species, such as elemental sulfur, jarosite, phosphates and oxides, were identified. These interfacial modifications are correlated with changes in the open circuit potential (OCP) values during immersion of pyrite and surface modified pyrites in 0 K culture medium. Electrochemical characterization showed a decrease in mineral oxidation capacity, which directly affects the extent of leaching and possibly, of the interaction with other elements participating in the process, such as microorganisms. To study the interactions among bacteria and the pyrite mineral suffering different surface modifications, the attachment of the bioleaching bacterium Leptospirillum sp. was evaluated. Graphical abstract Unlabelled Image Highlights • Raman spectroscopy was used to characterize chemically oxidized pyrite surface. • Simple short exposure to acid media further modifies pyrite-oxidized surface. • Polysulfides, elemental sulfur, jarosite, phosphates and oxides were identified. • Electrochemical characterization show different OCPs and reactivity. • Microbial attachment was affected by the compounds exposed by the pyrite. [ABSTRACT FROM AUTHOR]

The lithium titanate defect spinel, Li4Ti5O12 (LTO), is a promising 'zero-strain' anode material for lithium-ion batteries in cycling-demanding applications. However, the low-rate capability limits its range of applications. Surface modifications, for example, coating and defect engineering, play an intriguing role in interfacial electrochemical processes. Herein, a novel synthesis of highly oxygen-deficient 'defective-LTO' anode material with high-rate performance is reported. It is synthesized using conventional precursors via a one-pot thermal reduction process. A high level of oxygen vacancies of ≈6.5 at% and conformal amorphous carbon coating are achieved simultaneously, resulting in a compounding effect for a high discharge capacity of 123 mAh g−1 with Coulombic efficiency of 99.8% at 10 C-rate. Ab initio calculations foresight that oxygen vacancies increase the electron donor density of the neighboring titanium atoms, while conformal amorphous carbon significantly lowers interfacial charge-transfer resistance. The formation mechanism, as well as the origin of enhanced electrochemical properties, is elaborated in this paper. [ABSTRACT FROM AUTHOR]

Poly(Phenylene vinylene) anionic polyelectrolyte (PVBT‐SO3) was found to be an efficient hole extraction layer for inverted perovskite solar cells. It can be cast from an aqueous solution and does not require thermal annealing for improved device performance. The devices show maximum solar cell efficiency of 15.9% and exhibit improved stability under ambient conditions and enhanced charge extraction. [ABSTRACT FROM AUTHOR]

ABSTRACT The interfacial changes associated with a series of polypropylene based composite materials with modified interphases from the reinforcement side, from the matrix side and both were studied by following their dynamic mechanical behavior. Composites consisted in an isotactic polypropylene (iPP) matrix, a series of talc with different surface functionalities (hydroxyl, chloride, n-butyl amine, and silanes) and a commercial interfacial agent form the matrix side (iPP-SA with 5% of grafts). A comprehensive interpretation of the link existing between the dynamic mechanical responses of the series of 75/25 iPP/talc composites and the molecular relaxation spectrum occurring in the polymer phase of the composites is made with emphasis on the role played by the interfacial modifications performed from each and both sides of the interphase. Dynamic mechanical analysis has been used here to study how the intended interfacial modifications affected the behavior of the composites. The efficiency of the interfacial phenomena is discussed from a phenomenological point of view as well as by considering classical criteria such as the glass transition temperature and the glass to rubbery transition. Finally, a correlation between mechanical parameters from the microscopic scale and others from the macroscopic scale appears to emerge. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42678. [ABSTRACT FROM AUTHOR]

Degradation of halide perovskite materials upon ambient exposure is one of the major challenge for their applications. Inorganic perovskite materials (such as CsPbI 2 Br) have emerged as potential candidate for stable perovskite optoelectronic applications in recent years owing to their appropriate bandgap and high thermal stability. However, the fabrication of high quality CsPbI 2 Br absorber layer is the main challenge to achieve highly efficient perovskite solar cells (PSCs). Herein, we report a strategy for the surface modification of CsPbI 2 Br layer via the treatment with isopropanol. The modified CsPbI 2 Br absorber layer has energetically more favorable band alignment with the C 60 which facilitates the efficient charge transfer and mitigate the energy loss at CsPbI 2 Br/C 60 interfaces. The inorganic PSCs with the architecture of ITO/NiO x /CsPbI 2 Br/C 60 /Cu showed open-circuit voltage (V OC) of 1.13 V and 30% improvement in the power conversion efficiency (PCE). Moreover, the devices exhibit less hysteresis index and excellent stability with no sign of degradation for 160 h. [Display omitted] • A modified post synthesis treatment of CsPbI 2 Br films was employed using isopropanol (IPA). • The CsPbI 2 Br treated film showed more favorable energetics for efficient electron extraction. • IPA treated device exhibited a 30% improvement in PCE with less hysteresis index when compared with devices without treatment. [ABSTRACT FROM AUTHOR]

In this study, we first revealed a green material-Poly-lysine as an interfacial layer (IFL) of electron-extraction layer (EEL) and investigated evolution of morphologies of the active layers in organic photovoltaics (OPVs). The surface structure of the active layers was characterized by atomic force microscopy (AFM) and the molecular packing features were revealed by grazing-incidence wide-angle X-ray scattering (GIWAXS). By embedding poly-lysine as IFL, we evidenced the changes of the blend film phase segregation and observed an increase order of molecular packing in preferential face-on orientation. The optimized blend film morphology facilitated the carrier extraction, thereby significantly improved the OPV performance with the best power conversion efficiency (PCE) of 12.5% and 15.3% for the PBDB-T-2Cl:IT-4F and PBDB-T-2F:Y6 blends, respectively. Compared with the controlled devices, the poly-lysine-modified devices showed significantly improved thermal-and photo-stability which keeps 80% of its initial efficiency after 400-h heating and illumination. As the first discovery of its general applicability of the promising IFL material, poly-lysine was further applied to fabricate a flexible OPV device using 100% bio-based polyethylene furandicarboxylate (PEF) substrate and its derived OPV device exhibited a PCE greater than 7% and maintained the 80% efficiency under the high bending radius of 3 mm. The present study suggests the potential application of using bio-based materials for flexible OPV applications. Image 1 • We have evaluated Poly-lysine as an interfacial layer in organic photovoltaics (OPVs). • The Poly-lysine derived PBDB-T-2F:Y6 device showed an improvement in PCE of up to 15.3%. • We demonstrated a flexible device using 100% bio-based polymer-PEF substrate. • The flexible device showed a PCE of greater than 7% and maintained the 80% performance under bending radius of 3 mm. [ABSTRACT FROM AUTHOR]

Li-garnets are promising inorganic ceramic solid electrolytes for lithium metal batteries, showing good electrochemical stability with Li anode. However, their brittle and stiff nature restricts their intimate contact with both the electrodes, hence presenting high interfacial resistance to the ionic mobility. To address this issue, a strategy employing ionic liquid electrolyte (ILE) thin interlayers at the electrodes/electrolyte interfaces is adopted, which helps overcome the barrier for ion transport. The chemically stable ILE improves the electrodes-solid electrolyte contact, significantly reducing the interfacial resistance at both the positive and negative electrodes interfaces. This results in the more homogeneous deposition of metallic lithium at the negative electrode, suppressing the dendrite growth across the solid electrolyte even at high current densities of 0.3 mA cm -2 . Further, the improved interface Li/electrolyte interface results in decreasing the overpotential of symmetric Li/Li cells from 1.35 to 0.35 V. The ILE modified Li/LLZO/LFP cells stacked either in monopolar or bipolar configurations show excellent electrochemical performance. In particular, the bipolar cell operates at a high voltage (≈8 V) and delivers specific capacity as high as 145 mAh g -1 with a coulombic efficiency greater than 99%., (© 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Garnet‐type solid‐state electrolytes (SSEs) have been widely studied as a promising candidate for Li metal batteries. Despite the common belief that inorganic SSEs can prevent dendrite propagation, garnet SSEs suffer from relatively low critical current density (CCD) at which the SSEs are abruptly short‐circuited by Li dendrites. In this study, the short‐circuiting mechanism of garnet Li7La2.75Ca0.25Zr1.75Nb0.25O12 (LLCZN) is investigated. It is found that instead of propagating uniaxially from one electrode to other in a dendritic form, metallic lithium is formed within the SSE. This can be attributed to the fact that electrons combine with Li ions at the grain boundary, which exhibits relatively high electronic conductivity, and then reduce Li+ to Li0 to cause short circuits. In order to reduce the electronic conductivity at the grain boundary, a thin layer of LiAlO2 is coated on the grain surface of LLCZN, which results in an improved CCD value. It is also found that under higher external voltages, the electronic conductivity of SSE becomes more significant, which is believed to be the origin of CCD. These findings not only shed light on the short‐circuiting mechanism of garnet‐type SSEs but also offer a novel perspective and useful guidance on their designs and modifications. [ABSTRACT FROM AUTHOR]

Planar heterojunction perovskite solar cells with a high efficiency up to 17.76% are fabricated by modifying the compact TiO2 (c-TiO2) with a [6,6]-phenyl-C61-butyric acid (PCBA) monolayer. High quality CH3NH3PbI3 films can be easily fabricated on PCBA-modified c-TiO2 substrates by a one-step solution processing method. Significant improvements of the device parameters are observed after PCBA modification. A high open-circuit voltage (Voc) of 1.16 V has been achieved, indicating that the PCBA monolayer can act as a hole blocking layer to reduce the trap site density atop the c-TiO2 and the hole recombination at the c-TiO2 /perovskite interface. The enhancement of the fill factor, as well as the partial quenching of the fluorescence of perovskite after modification with PCBA, reveals that the charge extraction is improved., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This review aims to provide an update on the development involving dielectric/organic semiconductor (OSC) interfaces for the realization of biofunctional organic field-effect transistors (OFETs). Specific focus is given on biointerfaces and recent technological approaches where biological materials serve as interlayers in back-gated OFETs for biosensing applications. Initially, to better understand the effects produced by the presence of biomolecules deposited at the dielectric/OSC interfacial region, the tuning of the dielectric surface properties by means of self-assembled monolayers is discussed. Afterward, emphasis is given to the modification of solid-state dielectric surfaces, in particular inorganic dielectrics, with biological molecules such as peptides and proteins. Special attention is paid on how the presence of an interlayer of biomolecules and bioreceptors underneath the OSC impacts on the charge transport and sensing performance of the device. Moreover, naturally occurring materials, such as carbohydrates and DNA, used directly as bulk gating materials in OFETs are reviewed. The role of metal contact/OSC interface in the overall performance of OFET-based sensors is also discussed., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)