Organic Passivation Research Articles

Enhancing Corrosion Resistance of Type 316L Stainless Steel in Marine Environments: Role of Surface Roughness and Organic Acid Passivation

Stainless steel is widely used in marine environments due to its excellent corrosion resistance properties. However, recent occurrences of corrosion issues related to Type 316L stainless steel in marine atmospheric environments have led to concerns regarding the suitability of Type 316L stainless steel material selection according to international standards. Factors such as surface roughness and passivation treatments can significantly affect the corrosion behavior of stainless steel in marine atmospheres. In particular, the surface roughness of conventional stainless steel piping can lead to corrosion in marine atmospheric environments when exposed for extended periods. Either option requires improving the surface roughness or applying passivation treatments to enhance corrosion resistance.This study examines the effect of surface roughness on the corrosion resistance of Type 316L stainless steel in a marine environment using potentiodynamic polarization and accelerated corrosion tests. In addition, the impact of organic acid passivation on the corrosion behavior of stainless steel in a marine atmosphere is investigated. Surface roughness was controlled by mechanical polishing, while organic acid passivation was achieved using a solution containing citric acid, phosphoric acid, and hydrogen peroxide. Electrochemical measurements and surface characterization techniques were employed to assess the corrosion resistance of the specimens. The results demonstrate that surface roughness and organic acid passivation significantly impact the corrosion resistance of stainless steel in a marine atmosphere. Understanding the synergistic effects of these factors is crucial for enhancing the durability and performance of stainless steel components in marine applications.

Surface Modification Strategies for Improved Electrochemical Performance and Long-Term Cyclability in Aqueous Zinc-Ion Batteries

Although aqueous zinc ion batteries are promising for grid-scale energy storage because of their low cost, safety, and high capacity, they are still limited by poor reversibility and a short cycle lifetime. The main causes of these problems are the spontaneous side reactions and the inhomogeneous deposition/dissolution behavior of the zinc electrode. In this study, we address these limitations by mitigating the inhomogeneous surface reactions of the zinc electrode, a key factor in achieving long-term cycling stability. By employing appropriate surface modification techniques to eliminate the intrinsic passivation layer and reduce surface roughness, we enable uniform electrochemical reactions on the electrode surface, resulting in homogeneous zinc deposition, accelerated electrochemical kinetics, and enhanced cycling performance. Two distinct surface modification strategies were utilized: chemical treatment and mechanical polishing. The chemical treatment entailed the application of acidic, neutral, or alkaline solutions to the zinc electrode, effectively removing the organic passivation layer, improving electrolyte wettability, rate capability, and enabling uniform zinc deposition. Mechanical polishing not only removed the passivation layer but also smoothed the rough surface of the zinc electrode, reducing local charge concentrations and further promoting uniform deposition, which enhanced long-term stability. Our research indicates that simple surface modification methods can significantly improve the electrochemical performance of zinc electrodes. These strategies may be applicable to other types of energy storage systems using metal foil-based electrode, including lithium, magnesium, and aluminum batteries, as well as zinc-ion batteries.

Tradeoffs among yield, cadmium bioavailability, nitrous oxide emission and bacterial community stability: Effects of iron-modified woody peat and nitrification inhibitors on soil-vegetable systems

Cadmium (Cd) pollution leads to soil degradation, decreases crop yield and affects human health through the food chain. Iron-modified woody peat (IMP) is an organic passivation material that significantly affects the migration of heavy metals in soil. Nitrification inhibitors are widely used to reduce greenhouse gas emissions. This study investigated the effects of the IMP and nitrification inhibitors dicyandiamide (DCD) and 3, 4-dimethylpyrazole phosphate on Cd content and form, crop yield, nitrous oxide (N2O) emission and bacterial communities in soil-lettuce systems. The simultaneous additions of IMP and DCD substantially reduced the soil available Cd content by 22.6 % and significantly promoted the lettuce yield by 42.9 %. Lettuce yield was significantly and negatively correlated with soil available Cd (correlation coefficient = −0.52). The simultaneous applications of IMP and nitrification inhibitors stimulated N2O emission risk by enhancing the soil NH4+-N contents and the relative abundances of Firmicutes, which could also decrease soil bacterial community stabilities. Therefore, tradeoffs among yield, Cd bioavailability, N2O emission and bacterial community stability should be comprehensively considered when evaluating the combined performances of IMP and nitrification inhibitors.

Self-cleaned surface of vanadium boride for long-lasting and boosted Fenton oxidation

Coupling extra electron supply with iron-mediated advanced oxidation processes (AOPs) is an efficient strategy for long-lasting oxidation of organic contaminants in environmental remediation. Many subsequent attempts have been made, such as homogeneous catalysts and metal catalysts, of which secondary organic pollution and surface passivation layers limit their application. In this work, metal borides as co-catalysts can efficiently accelerate the Fenton reaction by firmly sacrificing electrons to Fe(III) reduction. Among multiple metallic borides, vanadium boride (VB2) performs superiorly as dual active sites to solve the Fe(III) cycle dilemma and quickly generate hydroxyl radicals via Fenton reaction for almost completely eliminating almost carbamazepine (CBZ) in VB2/Fe(III)/H2O2. Characterization analysis and the density functional theory (DFT) calculation unveil that the synergistic effect of V and B on the surface of VB2 makes Fe-O bonds of FeOH2+ weaker (from 173.8 pm to 178.4 pm) to produce more active Fe(III) species. And meanwhile, active Fe(III) can be rapidly reduced into Fe(II) on the surface of VB2 and then be completely released into solution for subsequent Fenton reaction and hydroxyl radical generation. More importantly, VB2 performs steadily and efficiently for 7th consecutive test in VB2/Fe(III)/H2O2 to degrade more than 95% CBZ, resulting from the self-cleaning surface of VB2 to expose reactive regions for persistent electron sacrifice and sustainably stimulative Fenton oxidation. Therefore, this research offers the detailed fundamental perception into the genesis of VB2 as well as a novel electron donor for boosting Fenton oxidation towards water remediation.

Ultrathin Self-Assembled Monolayer for Effective Silicon Solar Cell Passivation.

Passivation technology is crucial for reducing interface defects and impacting the performance of crystalline silicon (c-Si) solar cells. Concurrently, maintaining a thin passivation layer is essential for ensuring efficient carrier transport. With an ultrathin passivated contact structure, both Silicon Heterojunction (SHJ) cells and Tunnel Oxide Passivated Contact (TOPCon) solar cells achieve an efficiency surpassing 26%. To reduce production costs and simplify solar cell manufacturing processes, the rapid development of organic material passivation technology has emerged. However, its widespread industrial production is hindered by environmental safety concerns, such as strong acid corrosion and biological and ecological safety issues. Here, we discovered a low-cost self-assembled monolayer (SAM) hole-selective transport material known as 2PACz ([2-(9H-carbazol-9-yl) ethyl] phosphonic acid) with phosphate groups to form c-Si solar cells for the first time. The ultrathin film of 2PACz with phosphate groups can establish strong and stable P-O-Si bonds on the silicon surface. Meanwhile, like 2PACz, a uniform ultrathin film with a carbazole function group can offer electron-localizing and thus hole-selective properties, which provides ideas for studying dopant-free silicon solar cells. As a result of such interfacial passivation engineering, it plays an important role in repairing porous structures, such as pyramid-textured silicon surfaces, and cutting losses during the commercialization of c-Si solar cells. Crucially, this advancement offers insights for the development of new high-efficiency ultrathin film passivation methods in the postsilicon era.

Design and Architecture Definition for Advanced 3D Fan-Out Wafer-Level Packaging

Advanced 2.5D/3D wafer-level fan-out packaging technologies have been studied widely in literature and industry in recent years. Miniaturization, reduction in manufacturing costs, improvement in performance, and lower power consumption using packaging technologies drive increase in interconnect density and pitch scaling. Heterogeneous systems in package used in advanced packaging often include a combination of silicon, epoxy underfill or mold compounds, and organic or inorganic passivation or redistribution layers. This heterogeneity poses challenges with manufacturability, process selection, package architecture, and test vehicle design. The coefficient of thermal expansion mismatch, wafer warpage, and wafer yield are some of the critical process challenges. Delamination of silicon side wall or passivation to epoxy underfill or mold compound, joint fatigue are critical reliability challenges. This article explores various processes and reliability challenges with 3D wafer-level fan-out packaging and provides package design and architecture guidelines to overcome these failure modes. Stacked die-to-wafer test vehicles have been used for data collection. Different assembly materials, processes, and tooling have been evaluated to define comprehensive design rules.

Optimizing feedstock organic composition to regulate humification and heavy metal passivation during solid-state anaerobic digestion

This study uncovered the impacts of feedstock organic composition, comprising proteins, lignocellulose, and lipids, on humification and passivation of heavy metals (HMs) in solid-state anaerobic digestion (SSAD). Mantel tests and partial least squares structural equation modeling (PLS-SEM) results revealed that copper (Cu) and zinc (Zn) passivation predominantly occurred through complexation with humic acid (HA). In contrast, lead (Pb) and chromium (Cr) passivation were pH-dependent as influenced by substrate conditions in SSAD. Increasing protein content in the feedstock facilitated lignocellulose biodegradation to enhance HA formation, and thus augmenting Cu and Zn passivation. Furthermore, the improved biodegradation of organic components elevated the substrate pH, further enhancing Pb and Cr passivation. Such improvement was notable when the protein: lignocellulose: lipid ratio of feedstock was regulated to 4.1:3.7:2.2, which increased HA contents to 35.25% and pH to 9 to enhance the passivation of Cu, Pb, and Cr by 0.48%, 52.0%, and 17.9%, respectively.

Unveiling the impact of organic cation passivation on structural and optoelectronic properties of two-dimensional perovskites thin films

Several organic cations have been used to passivate perovskite films; however, selecting the optimal cation remains challenging. In this work, we carried out density functional theory calculations to understand the effects induced by 17 different organic cations on the passivation (P-cations) of thin two-dimensional P2 (MAn−1)PbnI3n+1 perovskites films, where n=1 and 2. We found that the interactions between different types of P-cations and the inorganic slab affect the length and angles of the bonds within the inorganic framework (PbI6-octahedra). In general, the binding mechanism includes the interactions of organic cations with the inorganic framework, which leads to the accumulation of electron density within the halides, indicative of Brønsted–Lowry acid–base interactions. Oxygenated groups facilitate additional H-bond formation through -OH and -COOH groups, promoting the localization of the electron density between layers and improving the energetic stability of the system. Based on the results and analysis, we found that three P-cations might have higher potential for real-life applications, namely 4-fluorophenylethylammonium (FPEA), phenylethylammonium (PEA) and butylammonium (BtA).

Inorganic surface passivation strategies of metal halide perovskites

AbstractMetal halide perovskites have demonstrated considerable promise across various optoelectronic applications. Surface passivation serves as a pivotal strategy to obtain high‐quality perovskite materials, either in a manner of bulk thin film or nanocrystal, with superior optoelectronic properties and stability. The current research focus in this regard primarily revolves around the use of organic molecules to passivate the surface of perovskites. However, organic passivation molecules always suffer from chemical instability and weak secondary bonding modes, resulting in an unstable surface passivation motif. Inorganic materials, possessing more stable chemical structures and stronger chemical bonding than their organic counterparts, offer the opportunities to construct more robust passivation for the perovskite surfaces. Herein, in this review, we summarized and assessed recent advancements in inorganic surface passivation strategies for perovskite materials and devices, ranging from nanocrystals to bulk films. By discussing the mechanisms behind various inorganic passivation strategies, we aim to offer mechanistic insights and guidelines for future developments of more targeted surface passivation approaches tailored for perovskite materials and devices.

Multishell Silver Indium Selenide-Based Quantum Dots and Their Poly(methyl methacrylate) Composites for Application in Red-Light-Emitting Diodes.

In this work, the production of novel multishell silver indium selenide quantum dots (QDs) shelled with zinc selenide and zinc sulfide through a multistep synthesis precisely designed to develop high-quality red-emitting QDs is explored. The formation of the multishell nanoheterostructure significantly improves the photoluminescence quantum yield of the nanocrystals from 3% observed for the silver indium selenide core to 27 and 46% after the deposition of the zinc selenide and zinc sulfide layers, respectively. Moreover, the incorporation of the multishelled QDs in a poly(methyl methacrylate) (PMMA) matrix via in situ radical polymerization is investigated, and the role of thiol ligand passivation is proven to be fundamental for the stabilization of the QDs during the polymerization step, preventing their decomposition and the relative luminescence quenching. In particular, the role of interface chemistry is investigated by considering both surface passivation by inorganic zinc chalcogenide layers, which allows us to improve the optical properties, and organic thiol ligand passivation, which is fundamental to ensuring the chemical stability of the nanocrystals during in situ radical polymerization. In this way, it is possible to produce silver-indium selenide QD-PMMA composites that exhibit bright red luminescence and high transparency, making them promising for potential applications in photonics. Finally, it is demonstrated that the new silver indium selenide QD-PMMA composites can serve as an efficient color conversion layer for the production of red light-emitting diodes.

4F-Phenethylammonium chloride as a key component for interfacial engineering of wide-bandgap perovskite absorber

The development of high-efficiency and stabilized tandem solar cells and solar cells for indoor light harvesting relies heavily on the fabrication of wide-bandgap (WBG) perovskite solar cells (PSCs) that exhibit exceptional efficiency and stability. In this study, we introduce an effective method for enhancing the optoelectronic properties of a 1.74 eV WBG perovskite absorber by interfacial engineering. Specifically, we utilize 4F-Phenethylammonium Chloride (4F-PEACL) as a key component for the surface treatment of perovskite layer. The treatment of perovskite with 4F-PEACL alters the surface stoichiometry, promoting self-doping and surface passivation, reducing surface recombination, and improving the optoelectronic properties of perovskite. Consequently, PCSs with perovskite treated with 4F-PEACL exhibit a notable power conversion efficiency of 20.27 %. Furthermore, the devices subjected to 4F-PEACL treatment demonstrate enhanced stability compared to the control devices across a range of testing settings. The findings of our study indicate that the utilization of organic salt perovskite passivation holds great potential in the development of efficient and stable WBG PSCs.

Engineering an organic electron-rich surface passivation layer for efficient and stable perovskite solar cells

Engineering an organic electron-rich surface passivation layer for efficient and stable perovskite solar cells

FTIR spectroscopy revealed nonplanar conformers, chain order, and packaging density in diOctadecylamine- and octadecylamine-passivated gold nanoparticles

This work reveals that diOctadecylamine (diODA) outperforms its primary amine counterpart ODA in intra- and intermolecular order, forming passivation monolayers on 5 nm small gold nanoparticles. We support this conclusion by meticulously analyzing the differences in the Fourier Transform Infrared (FTIR) spectrum of diODA and ODA molecules in their pure- and coordinated-to-gold-nanoparticle phases. Detailed diODA spectral data are scarce in the literature and are absent for diODA-passivated nanoparticles, whose merits have gone unnoticed. The analysis compares the signatures of defects and all indicators for molecular packing in the ligand. The results align with the High-Resolution Transmission Electron Microscopy (HR-TEM) based analysis. We observe unexpectedly that pure diODA molecules are not prone to form trans-gauche (TG) [CH3-CH2-gauche] end-conformation. At the same time, an intensive absorption structure at the relevant TG position around 760 cm−1 indicates its presence in pure ODA. The spectrum of pure ODA indicates higher energy of the internal kink defects in the vicinity of 1306 cm−1 than pure diODA. In the coordinated phase, both molecules reduce their initial energy. However, the observed better-pronounced red shift of the structures reveals a crystal-like chain arrangement for diODA. Consequently, the HR-TEM images reveal a spontaneous formation of 2D arrangement only for diODA passivated nanoparticles having nearly twice as large gold core separation as the one provided by ODA molecules. The present analysis can be used as a preliminary test in demanding applications where tightly packed coatings of nanoparticles with impenetrable organic passivation are essential.

High‐Performance Inverted Perovskite Solar Cells by Dual Interfaces Modification with Identical Organic Salt

AbstractThe improvement of power conversion efficiency (PCE) and stability of perovskite solar cells (PSC) relies on the enhanced quality of perovskite layer and the modification of its adjacent interfaces. For this purpose, a multifunctional organic passivation molecule 1‐(4‐Fluorophenyl) biguanide hydrochloride (F‐BHCl) is introduced to the top and bottom interfaces of the perovskite layer. The PCE of PSC after the modification of double interfaces with F‐BHCl is significantly increased from 22.41% (unmodified) to 25.14%, and the storage, thermal, and operation stability is also improved. The comprehensive theoretical and experimental studies verify that due to its versatile functional groups and adaptation, F‐BHCl can significantly improve the quality of perovskite film, fully passivate several kinds of common defects, smoothen the top surfaces of perovskite film, and construct “molecular bridges” with carrier transporters on both the top and bottom surfaces, leading to significantly reduced non‐recombination and carrier transport losses. As a result, a significant increase is achieved in the open circuit voltage and fill factor as well as the whole performance of the device.

Suppressing Interfacial Contact Energetics with Ultrathin Organic Passivation in Hysteresis-Free Lead-Halide Perovskite Transistors

Suppressing Interfacial Contact Energetics with Ultrathin Organic Passivation in Hysteresis-Free Lead-Halide Perovskite Transistors

Fluorinated organic ammonium salt passivation for high-efficiency and stable inverted CsPbI2Br perovskite solar cells.

All-inorganic CsPbI2Br inverted perovskite solar cells (PSCs) have drawn increasing attention because of their outstanding thermal stability and compatible process with tandem cells. However, relatively low open circuit voltage (Voc) has lagged their progress far behind theoretical limits. Herein, we introduce phenylmethylammonium iodide and 4-trifluoromethyl phenylmethylammonium iodide (CFPMAI) on the surface of a CsPbI2Br perovskite film and investigate their passivation effects. It is found that CFPMAI with a -CF3 substituent significantly decreases the trap density of the perovskite film by forming interactions with the under-coordinated Pb2+ ions and effectively suppresses the non-radiative recombination in the resulting PSC. In addition, CFPMAI surface passivation facilitates the optimization of energy-level alignment at the CsPbI2Br perovskite/[6,6]-phenyl C61 butyric acid methyl ester interface, resulting in improved charge extraction from the perovskite to the charge transport layer. Consequently, the optimized inverted CsPbI2Br device exhibits a markedly improved champion efficiency of 14.43% with a Voc of 1.12V, a Jsc of 16.31 mA/cm2, and a fill factor of 79.02%, compared to the 10.92% (Voc of 0.95V) efficiency of the control device. This study confirms the importance of substituent groups on surface passivation molecules for effective passivation of defects and optimization of energy levels, particularly for Voc improvement.

Room-Temperature Organic Passivation for GaN-on-Si HEMTs With Improved Device Stability

In this work, we report an effective room-temperature passivation strategy for GaN-on-Si high-electron-mobility transistors (HEMTs) to improve device stability by introducing a spin-coated CYTOP organic passivation layer. This CYTOP coating can suppress the interface states of the devices to a low level of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim$</tex-math> </inline-formula> 10 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text{12}}$</tex-math> </inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-\text{2}}\cdot$</tex-math> </inline-formula> eV <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-\text{1}}$</tex-math> </inline-formula> at a shallow energy trap of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim$</tex-math> </inline-formula> 0.30 eV. As a result, improved device stability is realized, featuring reduced leakage current, smaller voltage hysteresis, reduced current collapse, and mitigated device degradation after long-term electrical stress. Besides, it is found that the CYTOP-passivated HEMT can operate with stable rectification behavior under an elevated temperature of 250 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula> C, confirming the high-temperature robustness of this organic passivation. These results highlight the potential of such room-temperature passivation strategy for further applications in electronic systems under complex conditions and harsh environments.

Enhanced Efficiency and Stability of Inverted CsPbI2Br Perovskite Solar Cells via Fluorinated Organic Ammonium Salt Surface Passivation.

All-inorganic perovskite solar cells (PSCs) have recently received increasing attention due to their outstanding thermal stability. However, the performance of these devices, especially for the devices with a p-i-n structure, is still inferior to that of the typical organic-inorganic counterparts. In this study, we introduce phenylammonium iodides with different side groups on the surface of the CsPbI2Br perovskite film and investigate their passivation effects. Our studies indicate that the 4-trifluoromethyl phenylammonium iodide (CFPA) molecule with the -CF3 side group effectively decreases the trap density of the perovskite film by forming interactions with the undercoordinated Pb2+ ions and significantly inhibits the nonradiative recombination in the derived PSC, leading to an enhanced open-circuit voltage (Voc) from 0.96 to 1.10 V after passivation. Also, the CFPA post-treatment enables better energy-level alignment between the conduction band minimum of CsPbI2Br perovskite and [6,6]-phenyl C61 butyric acid methyl ester, thereby enhancing the charge extraction from the perovskite to the charge transport layer. These combined benefits result in a significant enhancement of the power conversion efficiency from 11.22 to 14.37% for inverted CsPbI2Br PSCs. The device without encapsulation exhibits a degradation of only ≈4% after 1992 h in a N2 glovebox.

Solvent optimization on novel organic passivating layer for the effective passivation of perovskite films

The efficiency of perovskite solar cells (PSCs) has sparked interest in both academic and industrial circles. The existence of charge traps within the perovskite film, as well as charge recombination occurring at grain boundaries and defects in PSCs, significantly limits the power conversion efficiency (PCE). In this study, we investigate the introduction of a novel organic passivating layer on the perovskite surface, with the goal of enhancing the performance and stability of perovskite solar cells. Through experimentation, we assessed the incorporation of this organic passivating layer on the perovskite film using various solvents and discovered that toluene is the most effective solvent for both the preparation and utilization of this passivating layer in PSCs.

Restricted hydrolysis reaction of Si3N4 via nonionic polymer adsorption in advanced shallow trench isolation chemical mechanical planarization

The adoption of ultra-fine nanoparticles as an abrasive has garnered notable attention in shallow trench isolation (STI) chemical mechanical planarization (CMP) due to its potential in scratch reduction. However, the poor removal rate, attributed to the physicochemical interaction between abrasive and conventional organic passivation agent, limits the introduction of ultra-fine nanoparticles. Here, a nonionic polymer polyvinyl alcohol (PVA), without particle interaction, is proposed as a novel passivation agent to restrict the hydrolysis reaction of Si3N4 film in the advanced STI CMP process. The selective adsorption of PVA onto the Si3N4 film lowers its removal rate by suppressing the hydrolysis reaction via hydrogen bonding while the removal rate of SiO2 film remains constant. Moreover, the uniformity of SiO2 removal is improved due to the enhanced fluidity of slurry, resulting from increased wettability between pad and slurry. As a result, the removal selectivity between both films has been improved to 113.4:1 and the in-wafer-uniformity (IWU) of SiO2 film is supplemented by 96.8 % simultaneously.