Fullerene derivatives are widely employed as efficient electron-transporting layers (ETLs) in p-i-n perovskite photovoltaics but face challenges in mitigating interfacial recombination losses and ensuring stable film morphology. Non-fullerene acceptors (NFAs), commonly utilized in organic photovoltaics, present a promising alternative to fullerene-based ETLs. Nevertheless, the suboptimal performance of NFA-based devices underscores the need for molecular engineering to tailor their properties.
View Article and Find Full Text PDFMetal halide perovskite materials inherently possess imperfections, particularly under nonequilibrium conditions, such as exposure to light or heat. To tackle this challenge, we introduced stearate ligand-capped nickel oxide (NiO), a redox-sensitive metal oxide with variable valence, into perovskite intermediate films. The integration of NiO improved the efficiency and stability of perovskite solar cells (PSCs) by offering multifunctional roles: (1) chemical passivation for ongoing defect repair, (2) energetic passivation to bolster defect tolerance, and (3) field-effect passivation to mitigate charge accumulation.
View Article and Find Full Text PDFDeep learning object detection networks require a large amount of box annotation data for training, which is difficult to obtain in the medical image field. The few-shot object detection algorithm is significant for an unseen category, which can be identified and localized with a few labeled data. For medical image datasets, the image style and target features are incredibly different from the knowledge obtained from training on the original dataset.
View Article and Find Full Text PDFDeveloping cost-effective metal electrodes is essential for reducing the overall cost of perovskite solar cells (PSCs). Although copper is highly conductive and economical, it is rarely used as a positive electrode in efficient n-i-p PSCs due to its unmatched Fermi level and low oxidation threshold. We report herein that modification for the inner surface of electrodes using mercaptopyridine-based molecules readily tunes the electronic and chemical properties of copper, which has been achieved by fine-tuning the substituents of mercaptopyridines.
View Article and Find Full Text PDFPerovskite solar cells (PeSCs) using FAPbI perovskite films often exhibit unfavorable phase transitions and defect-induced nonradiative interfacial recombination, resulting in considerable energy loss and impairing the performance of PeSCs in terms of efficiency, stability, and hysteresis. In this work, a facile interface engineering strategy to control the surface structure and energy-level alignment of perovskite films by tailoring the interface between the FAPbI film and hole-transporting layer using 4-hydroxypicolinic acid (4HPA) is reported. According to density functional theory studies, 4HPA has prominent electron delocalization distribution properties that enable it to anchor to the perovskite film surface and facilitate charge transfer at the interface.
View Article and Find Full Text PDFAlthough the perovskite solar cells have been developed rapidly, the industrialization of perovskite photovoltaics is still facing challenges, especially considering their stability issues. Here, the new type of benzimidazolium salt, N,N'-dialkylbenzimidazolium iodide, is proposed and functionalized to convert the three-dimensional (3D) FACs-perovskite films into one-dimensional (1D) capping layer topped 1D/3D structure either in individual device or module levels. This conformal interface modulation demonstrates that not only can effectively stabilize FACs-based perovskite films by inhibiting the lateral and vertical iodide diffusions in devices or modules, ensuring an excellent operation and environmental stability, but also provides an excellent charge transporting channel through the well-designed 1D crystal structure.
View Article and Find Full Text PDFResearch on solvent chemistry, particularly for halide perovskite intermediates, has been advancing the development of perovskite solar cells (PSCs) toward commercial applications. A predictive understanding of solvent effects on the perovskite formation is thus essential. This work systematically discloses the relationship among the basicity of solvents, solvent-contained intermediate structures, and intermediate-to-perovskite α-FAPbI evolutions.
View Article and Find Full Text PDFPower conversion efficiency (PCE) and long-term stability are two vital issues for perovskite solar cells (PSCs). However, there is still a lack of suitable hole transport layers (HTLs) to endow PSCs with both high efficiency and stability. Here, NiO nanoparticles are promoted as an efficient and 85 °C/85%-stable inorganic HTL for high-performance n-i-p PSCs, with the introduction of perovskite quantum dots (QDs) between perovskite and NiO as systematic interfacial engineering.
View Article and Find Full Text PDFInt J Ophthalmol
April 2022
Aim: To investigate the effect of leptin on the angiogenesis of RF/6A cells (monkey retinal choroidal endothelial cells) and test the cellular signaling in the mechanism.
Methods: RF/6A cells were cultured and randomly divided into four groups: normal control, with leptin at 50, 100, 200 ng/mL for cell counting kit-8 (CCK8). RF/6A cell proliferation and migration were examined by Transwell assays, while RF/6A cell tube formation by Matrigel assay.
Hole transport materials (HTMs) play a requisite role in n-i-p perovskite solar cells (PSCs). The properties of HTMs, such as hole extraction efficiency, chemical compatibility, film morphology, ion migration barrier, and so on, significantly affect PSCs' power conversion efficiencies (PCEs) and stabilities. Up till now, researchers have devoted much attention to developing new types of HTMs as well as promoting pristine HTMs using numerous strategies.
View Article and Find Full Text PDFJ Phys Chem Lett
February 2022
The preparation of solution-processed metal halide perovskites is interwoven with research on their intermediate chemistry. In this Perspective, molecule-level insights are provided into how Lewis base additives (LBAs), , DMSO and NMP, facilitate powder-to-film formation processes (, the chemical origin of intermediate structures, structural evolution of intermediate-to-perovskite phase transition, and device-based application of intermediate-evolved perovskites). LBAs interact with Lewis acid species (cationic A or B sites) of ABX structures with separate probability in terms of coordination bonds or hydrogen bonds to form two types of intermediate structures, inducing significant differences within intermediate-to-perovskite processes.
View Article and Find Full Text PDFOwing to the ionic nature of lead halide perovskites, their halide-terminated surface is unstable under light-, thermal-, moisture-, or electric-field-driven stresses, resulting in the formation of unfavorable surface defects. As a result, nonradiative recombination generally occurs on perovskite films and deteriorates the efficiency, stability, and hysteresis performances of perovskite solar cells (PSCs). Here, a surface iodide management strategy was developed through the use of cesium sulfonate to stabilize the perovskite surface.
View Article and Find Full Text PDFIntroduction: Choroidal neovascularization (CNV) is the main pathological change of wet age-related macular degeneration. Anti-VEGF drugs are the most commonly used treatment for CNV. The biggest drawback of anti-VEGF drugs is the recurrence of CNV, which requires repeated therapy several times.
View Article and Find Full Text PDFPerovskite solar cells (PSCs) with organic hole transporting layers (o-HTLs) have been widely studied due to their convenient solution processing, but it remains a big challenge to improve the hole mobilities of commercially available organic hole transporting materials without ion doping while maintaining the stability of PSCs. In this work, we demonstrated that the introduction of perovskite quantum dots (QDs) as interlayers between perovskite layers and dopant-free o-HTLs (P3HT, PTAA, Spiro-OMeTAD) resulted in a significantly enhanced performance of PSCs. The universal role of QDs in improving the efficiency and stability of PSCs was validated, exceeding that of lithium doping.
View Article and Find Full Text PDFSolar steam generation is receiving considerable interest because of its potential application in wastewater treatment and desalination. Many devices with various photothermal materials and structures have been demonstrated to be solar steam evaporators by improving their light absorption, heat loss, water transportation, and vapor escape. However, developing a biomass-based evaporator with heat localization and rapid water transportation is highly desired yet still challenging.
View Article and Find Full Text PDFPerovskite films prepared with CHNH molecules under ambient conditions have led to rapid fabrication of perovskite solar cells (PSCs), but there remains a lack of mechanistic studies and inconsistencies with operability in their production. Here the crystal structure of CHNH-CHNHPbI was analyzed to involve hydrogen bonds (CHNH···CHNH) and has guided the facile, reproducible preparation of high-quality perovskite films under ambient conditions. Hydrogen bonds within CHNH···CHNH dimers were found in the CHNH-CHNHPbI intermediates, accompanied by 1D-PbI chains (δ-phase).
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2019
The sol-gel (SG) method has been well-documented as one useful way to produce ZnO films as an excellent electron transport material (ETM) for efficient perovskite solar cells (PSCs). Generally, the precursor films containing zinc acetate dihydrate and a stabilizing ligand monoethanolamine (EA) were annealed to obtain ZnO films. A noteworthy issue is the commonly reported annealing temperature () in a wide range of 150-600 °C.
View Article and Find Full Text PDFThe chemical reactivity and/or the diffusion of Ag atoms or ions during thermal processing can cause irreversible structural damage, hindering the application of Ag nanowires (NWs) in transparent conducting films and other applications that make use of the material's nanoscale properties. Here, we describe a simple and effective method for growing monolayer SnO on the surface of Ag nanowires under ambient conditions, which protects the Ag nanowires from chemical and structural damage. Our results show that Sn and Ag atoms undergo a redox reaction in the presence of water.
View Article and Find Full Text PDFInt J Ophthalmol
February 2019
Aim: To evaluate the efficacy and safety of intravitreal injection of conbercept in patients with neovascular age-related macular degeneration (AMD).
Methods: Retrospective review of 66 eyes of 63 patients with neovascular AMD. All patients received 0.