Seeded Growth Process Research Articles

Precisely Prepared Hierarchical Micelles of Polyfluorene‐block‐Polythiophene‐block‐Poly(phenyl isocyanide) via Crystallization‐Driven Self‐Assembly

AbstractThe precise preparation of hierarchical micelles is a fundamental challenge in modern materials science and chemistry. Herein, poly(di‐n‐hexylfluorene)‐block‐poly(3‐tetraethylene glycol thiophene) (poly(1m‐b‐2n)) diblock copolymers and polyfluorene‐block‐polythiophene‐block‐poly(phenyl isocyanide) triblock copolymers were synthesized using a one‐pot process via the sequential addition of corresponding monomers using a Ni(II) complex as a single catalyst for living/controlled polymerization. The crystallization‐driven self‐assembly of amphiphilic conjugated poly(1m‐b‐2n) led to the formation of nanofibers with controlled lengths and narrow dispersity. The block copolymers exhibited white, yellow, and red emissions in different self‐assembly states. By using uniform poly(1m‐b‐2n) nanofibers as seeds, introducing the polyfluorene‐block‐polythiophene‐block‐poly(phenyl isocyanide) triblock polymer as a unimer in the seed growth process, and adjusting the structure of the poly(phenyl isocyanide) block and the polarity of self‐assembly solvent, A−B−A triblock micelles, multiarm branched micelles, and raft micelles were prepared.

Precisely Prepared Hierarchical Micelles of Polyfluorene-block-Polythiophene-block-Poly(phenyl isocyanide) via Crystallization-Driven Self-Assembly.

The precise preparation of hierarchical micelles is a fundamental challenge in modern materials science and chemistry. Herein, poly(di-n-hexylfluorene)-block-poly(3-tetraethylene glycol thiophene) (poly(1m-b-2n)) diblock copolymers and polyfluorene-block-polythiophene-block-poly(phenyl isocyanide) triblock copolymers were synthesized using a one-pot process via the sequential addition of corresponding monomers using a Ni(II) complex as a single catalyst for living/controlled polymerization. The crystallization-driven self-assembly of amphiphilic conjugated poly(1m-b-2n) led to the formation of nanofibers with controlled lengths and narrow dispersity. The block copolymers exhibited white, yellow, and red emissions in different self-assembly states. By using uniform poly(1m-b-2n) nanofibers as seeds, introducing the polyfluorene-block-polythiophene-block-poly(phenyl isocyanide) triblock polymer as a unimer in the seed growth process, and adjusting the structure of the poly(phenyl isocyanide) block and the polarity of self-assembly solvent, A-B-A triblock micelles, multiarm branched micelles, and raft micelles were prepared.

Reversible Modulation of Plasmonic Coupling of Gold Nanoparticles Confined within Swellable Polymer Colloidal Spheres.

Dynamic optical modulation in response to stimuli provides exciting opportunities for designing novel sensing, actuating, and authentication devices. Here, we demonstrate that the reversible swelling and deswelling of crosslinked polymer colloidal spheres in response to pH and temperature changes can be utilized to drive the assembly and disassembly of the embedded gold nanoparticles (AuNPs), inducing their plasmonic coupling and decoupling and, correspondingly, color changes. The multi-responsive colloids are created by depositing a monolayer of AuNPs on the surface of resorcinol-formaldehyde (RF) nanospheres, then overcoating them with an additional RF layer, followed by a seeded growth process to enlarge the AuNPs and reduce their interparticle separation to induce significant plasmonic coupling. This configuration facilitates dynamic modulation of plasmonic coupling through the reversible swelling/deswelling of the polymer spheres in response to pH and temperature changes. The rapid and repeatable transitions between coupled and decoupled plasmonic states of AuNPs enable reversible color switching when the polymer spheres are in colloidal form or embedded in hydrogel substrates. Furthermore, leveraging the photothermal effect and stimuli-responsive plasmonic coupling of the embedded AuNPs enables the construction of hybrid hydrogel films featuring switchable anticounterfeiting patterns, showcasing the versatility and potential of this multi-stimuli-responsive plasmonic system.

Selenium-Doped Seeded Growth of Truncated Octahedral Gold Nanocrystals with Surface Concavities for Surface-Enhanced Raman Spectroscopy.

Concave nanocrystals stand out as a testament to the importance of the nanoscale morphology in dictating the functional properties of materials. In this report, we introduce a facile synthesis method for producing gold (Au) nanocrystals with a truncated octahedral morphology that features surface concavities (Au CNTOs). The incorporation of selenium (Se) doping into the truncated octahedral Au seeds was essential for their enlargement and the formation of concave structures. By simply adjusting the quantity of seeds, we could control the size of the nanocrystals while maintaining their distinctive morphology and surface concavity. The formation mechanism suggests that Se doping likely passivates the side faces, thereby slowing growth and promoting atomic deposition at the edges and corners. The resulting Se-doped Au CNTOs exhibited strong localized surface plasmon resonance (LSPR) absorptions in the visible spectrum and the SERS performance of their assemblies was demonstrated through crystal violet detection, reaching enhancement factors around 105. This study presents an innovative approach to synthesizing concave Au nanocrystals through the incorporation of selenium during a seeded growth process, offering insights into the strategic design of plasmonic nanostructures.

Disentangling Competitive and Synergistic Chemical Reactivities During the Seeded Growth of High-Entropy Alloys on High-Entropy Metal Sulfide Nanoparticles.

The seeded growth of one type of nanoparticle on the surface of another is foundational to synthesizing many multifunctional nanostructures. High-entropy nanoparticles that randomly incorporate five or more elements offer enhanced properties due to synergistic interactions. Incorporating high-entropy nanoparticles into seeded growth platforms is essential for merging their unique properties with the functional enhancements that arise from particle-particle interactions. However, the complex compositions of high-entropy materials complicate the seeded growth process due to competing particle growth and chemical reactivity pathways. Here, we design and synthesize a 36-member nanoparticle library to identify and disentangle these competitive interactions, ultimately defining chemical characteristics that underpin the seeded growth of high-entropy alloys on high-entropy metal sulfide nanoparticles. As a model system, we focus on (Cu,Zn,Co,In,Ga)S-SnPdPtRhIr, which combines a high-entropy metal sulfide semiconductor with a high-entropy alloy catalyst. We study the seeded growth of all possible pairwise combinations of Sn, Pd, Pt, Rh, Ir, and SnPdPtRhIr on the metal sulfides Cu1.8S, ZnS, Co9S8, CuInS2, CuGaS2, and (Cu,Zn,Co,In,Ga)S, which have comparable morphologies and sizes. Through these studies, we uncover unexpected chemical reactivities, including cation exchange, redox reactions, and diffusion. Reaction temperature, threshold reduction potentials, metal/sulfide chemical reactivity, and the relative strengths of the various bonds that could be formed during particle growth emerge as the primary factors that underpin seeded growth. Finally, we disentangle these competitive and synergistic chemical reactivities to generate a reactivity map that provides practical guidelines for achieving seeded growth in compositionally complex systems.

Colorimetric Pressure Sensing by Plasmonic Decoupling of Silver Nanoparticles Confined within Polymeric Nanoshells.

Employing a plasmonic decoupling mechanism, we report the design of a colorimetric pressure sensor that can respond to applied pressure with instant color changes. The sensor consists of a thin film of stacked uniform resorcinol-formaldehyde nanoshells with their inner surfaces functionalized with silver nanoparticles. Upon compression, the flexible polymer nanoshells expand laterally, inducing plasmonic decoupling between neighboring silver nanoparticles and a subsequent blue-shift. The initial color of the sensor is determined by the extent of plasmonic coupling, which can be controlled by tuning the interparticle distance through a seeded growth process. The sensing range can be conveniently customized by controlling the polymer shell thickness or incorporating hybrid nanoshells into various polymer matrices. The new colorimetric pressure sensors are easy to fabricate and highly versatile, allow for convenient tuning of the sensing range, and feature significant color shifts, holding great promise for a wide range of practical applications.

Enhancing the interfacial strength of jute fiber/polylactic acid composites via surface carboxymethylation pretreatment and in situ growth of ZnO nanorods

ABSTRACT Jute fibers (JFs) are considered an excellent reinforcement due to their abundant resources, environmental friendliness, low cost, lightweight, high specific strength and high specific modulus. However, they still suffer from surface defects that result in poor interfacial compatibility with polymeric matrices. This paper proposes a novel strategy that combines carboxymethylation pretreatment of JFs with in situ growth of ZnO nanorods (NRs) to enhance the mechanical properties of JFs and interfacial properties of JFs/polylactic acid (PLA) composites. The results indicate that carboxymethylation is a more effective method for removing pectin from the surface of JFs compared to conventional acid/alkali treatment. Subsequently, ZnO NRs are deposited in situ on the surface of carboxymethylation-treated JFs (c-JFs) through a seed-growth process, resulting in ZnO NRs@c-JFs. The impact of diverse process parameters, namely reaction time (t), reaction temperature (T) and concentration of zinc source (C), on the morphology and size of ZnO NRs was thoroughly investigated. Optimal process conditions were determined to be t = 6 h, T = 95°C, and C = 37.5 mmol·L−1, resulting in well-aligned ZnO NRs that completely filled up the grooves on JFs’ surface. Compared to untreated JFs, the tensile strength and tensile modulus of ZnO NRs@c-JFs increased by 30.4% and 81.6%, respectively, while exhibiting lower hygroscopicity and higher thermal stability. Furthermore, JFs-reinforced PLA composites were fabricated via hot pressing and their interfacial strength was evaluated using a microdroplet debonding test. Compared to untreated JFs/PLA, the combination of carboxymethylation and ZnO growth in ZnO NRs@c-JFs/PLA resulted in a significant 334% increase in interfacial shear strength (IFSS), indicating highly improved interface bonding between JFs and PLA resin, which was primarily attributed to the formation of a ‘zipper-like’ mechanical interlocking structure between ZnO NRs and PLA. This study provides valuable guidance for enhancing the interface of natural fiber/polymer composites and highlights their potential applications.

Effect Of Seed Soaking Time In Kno3 On Germination, Vegetative Morphology, And Results Of Bambara Chicken (Vigna Subterranea (L.) Verdcourt)

The The bambara groundnut has the potential to continue to be developed, but the obstacle faced is the very limited availability of bambara groundnut seeds. This is because there are no varieties from the results of breeding that are released and the low quality of the seeds. Low seed quality is caused by slow germination and results in the seed growth process being non-unison, this is influenced by seed dormancy. The purpose of this study was to determine the effect of soaking time in KNO3 on germination, vegetative morphology, and crop yield in the field by measuring seed viability and vigor, vegetative morphology and yield. The research was carried out for 4 months, from June-October 2022 which took place at the Agrotechnology Laboratory of the Muhammadiyah University of Malang and Dadaprejo Land, Batu City. The study was conducted using a simple Completely Randomized Block Design (RKLT) consisting of 10 treatments, and was repeated 3 times. The observed variables included moisture content, DB, PTM, IV, KCT, T50, plant height, number of leaves, leaf shape, leaf color, stem color, pod color, pod shape, number of pods, pod dry weight, number of seeds, dry weight seeds, yield potential, and weight of 1000 seeds. The results showed that the long soaking of seeds in KNO3 did not affect their vegetative morphology. Soaking time of seeds in KNO3 had no significant effect on DB and PTM values, but had a very significant effect on IV values, the number of leaves in the vegetative and generative phases. And it has a significant effect on the height of the KCT, T50, and plant height in the vegetative phase. As for the yield variable, the results showed no significant effect. Soaking time in KNO3 only affected germination, plant height, and number of bambara groundnut leaves.

Surface morphology regulation of colloidal Nanoparticles: A convenient Kinetically-Controlled seeded growth strategy

HypothesisExcept for chemical composition, surface morphology may endue colloidal nanoparticles with special interfacial behaviors, which is highly desired in certain scenarios, for example, ultra-stable Pickering emulsion for pharmaceutical applications where only limited chemicals are allowed. Herein, silica colloidal nanoparticle was chosen as a demo to illustrate a kinetically-controlled seeded growth strategy for the surface morphology regulation of colloidal nanoparticles. ExperimentsSurface chemical heterogeneity was primarily introduced to the silica seed nanoparticles by a seeded growth process in the presence of mixed silicate moieties with thermodynamical incompatibility. Then a further kinetically-controlled seeded growth step was performed to regulate the surface morphology of silica nanoparticles by promoting the selective condensation of tetraethoxysilane on the hydrophilic microdomains. FindingsUpon reducing the growing rate, tetraethoxysilane hydrolysates tend to condensate on silica microdomains, resulting in the formation of raspberry-like nanoparticles. The generality of the kinetically-controlled seeded growth strategy was validated by its success on differently-sized silica seeds modified with a range of silane coupling agents. This established strategy is facile and effective for massive production of raspberry-like silica colloidal nanoparticles with precisely-designed surface morphology and size, offering an ideal platform for the investigation on the exclusive contribution of morphology to the interfacial behaviors of nanoparticles.

Accelerating the peroxidase- and glucose oxidase-like activity of Au nanoparticles by seeded growth strategy and their applications for colorimetric detection of dopamine and glucose

The peroxidase (POD)- and glucose oxidase (GOx)-like activity of Au nanoparticles (AuNPs) is very low compared to that of natural enzymes, which greatly limits their application in biological field. Herein, we found that the enlargement of AuNPs by dopamine-mediated seeded growth strategy could significantly accelerate the POD- and GOx-like activity of AuNPs. The increase of the dual enzyme-like activities may be ascribed to the formation of branched Au superstructures in the seeded growth process. With the enhancement of dual enzyme-like activities of AuNPs, a sensitive and selective colorimetric detection of dopamine and glucose can be achieved respectively. This work is expected to provide a general method to synthesize other metal-based nanomaterials with branched superstructures and extend its application in areas such as medical diagnosis and therapy.

Two-step polymerization nanoarchitectonics for superior thin g-C3N4 nanosheets with modulated band gap and enhanced photo- and electro-chemical performance

The photo and electro catalytic activity of graphic carbon nitride (g-C3N4) depended strongly on the component, band gap, and thickness. In this paper, superior thin g-C3N4 composition homojunctions were created via a seed growth process by controlling precursor components. The result exhibited the change of microstructure, band gap, and photo and electro chemical properties of samples. Photocatalytic H2 generation and the photodegradation of rhodamine B (Rh B) were carried out to test photocatalytic activities. g-C3N4 seeds were fabricated using melamine and dicyandiamide named as MCN and DCN, respectively. The homojunctions were fabricated by the thermal polymerization of dicyandiamide using MCN as seeds. Because of a type II structure and high stability, sample 600MCN@720DCN10% revealed the best H2 generation which was ∼20 times of that of g-C3N4 nanosheets. The photocatalytic degradation of Rh B was completed within 15 min using this homojunction sample. In contrast, the homojunctions fabricated by the thermal polymerization of melamine using DCN as seeds revealed enhanced electrochemical performance. Sample 600DCN@720MCN exhibited the lowest overpotential and the best H2 evolution reaction performance. The result suggested the formation of homojunction improves photo and electrocatalytic activities.

Morphological and Optical Transitions during Micelle-Seeded Chiral Growth on Gold Nanorods.

Chiral plasmonics is a rapidly developing field where breakthroughs and unsolved problems coexist. We have recently reported binary surfactant-assisted seeded growth of chiral gold nanorods (Au NRs) with high chiroptical activity. Such a seeded-growth process involves the use of a chiral cosurfactant that induces micellar helicity, in turn driving the transition from achiral to chiral Au NRs, from both the morphological and the optical points of view. We report herein a detailed study on both transitions, which reveals intermediate states that were hidden so far. The correlation between structure and optical response is carefully analyzed, including the (linear and CD) spectral evolution over time, electron tomography, the impact of NR dimensions on their optical response, the variation of the absorption-to-scattering ratio during the evolution from achiral to chiral Au NRs, and the near-field enhancement related to chiral plasmon modes. Our findings provide further understanding of the growth process of chiral Au NRs and the associated optical changes, which will facilitate further study and applications of chiral nanomaterials.

Preparation of NbAs Single Crystal by the Seed Growth Process

A Weyl semimetal is a novel crystal with low-energy electronic excitations that behave as Weyl fermions. It has received worldwide interest and was believed to have introduced the next era of condensed matter physics after graphene and three-dimensional topological insulators. However, it is not easy to obtain a single large-sized crystal because there are many nucleations in the preparation process. A bottom-seed CVT growth method is proposed in this paper, and we acquired the large-sized, high-quality NbAs single crystals up to 4 × 3 × 3 mm3 finally. X-ray diffraction and STEM confirmed that they are tetragonal NbAs, which the key is to using the seed crystal in a vertical growth furnace. Notably, the photoelectric properties of the crystal are obtained under the existing conditions, which paves the way for follow-up work.

Tricomponent Supramolecular Multiblock Copolymers with Tunable Composition via Sequential Seeded Growth

AbstractSynthesis of supramolecular block co‐polymers (BCP) with small monomers and predictive sequence requires elegant molecular design and synthetic strategies. Herein we report the unparalleled synthesis of tri‐component supramolecular BCPs with tunable microstructure by a kinetically controlled sequential seeded supramolecular polymerization of fluorescent π‐conjugated monomers. Core‐substituted naphthalene diimide (cNDI) derivatives with different core substitutions and appended with β‐sheet forming peptide side chains provide perfect monomer design with spectral complementarity, pathway complexity and minimal structural mismatch to synthesize and characterize the multi‐component BCPs. The distinct fluorescent nature of various cNDI monomers aids the spectroscopic probing of the seeded growth process and the microscopic visualization of resultant supramolecular BCPs using Structured Illumination Microscopy (SIM). Kinetically controlled sequential seeded supramolecular polymerization presented here is reminiscent of the multi‐step synthesis of covalent BCPs via living chain polymerization. These findings provide a promising platform for constructing unique functional organic heterostructures for various optoelectronic and catalytic applications.

Tricomponent Supramolecular Multiblock Copolymers with Tunable Composition via Sequential Seeded Growth.

Synthesis of supramolecular block co-polymers (BCP) with small monomers and predictive sequence requires elegant molecular design and synthetic strategies. Herein we report the unparalleled synthesis of tri-component supramolecular BCPs with tunable microstructure by a kinetically controlled sequential seeded supramolecular polymerization of fluorescent π-conjugated monomers. Core-substituted naphthalene diimide (cNDI) derivatives with different core substitutions and appended with β-sheet forming peptide side chains provide perfect monomer design with spectral complementarity, pathway complexity and minimal structural mismatch to synthesize and characterize the multi-component BCPs. The distinct fluorescent nature of various cNDI monomers aids the spectroscopic probing of the seeded growth process and the microscopic visualization of resultant supramolecular BCPs using Structured Illumination Microscopy (SIM). Kinetically controlled sequential seeded supramolecular polymerization presented here is reminiscent of the multi-step synthesis of covalent BCPs via living chain polymerization. These findings provide a promising platform for constructing unique functional organic heterostructures for various optoelectronic and catalytic applications.

Origins of size effects in initially dislocation-free single-crystal silver micro- and nanocubes

We report phenomenal yield strengths—up to one-fourth of the theoretical strength of silver—recorded in microcompression testing of initially dislocation-free silver micro- and nanocubes synthesized from a multistep seed-growth process. These high strengths and the massive strain bursts that occur upon yield are results of the initially dislocation-free single-crystal structure of the pristine samples that yield through spontaneous nucleation of dislocations. When the pristine samples are exposed to a focused ion-beam to fabricate pillars and then compressed, the dramatic strain burst does not occur, and they yield at a quarter of the strength compared to the pristine counterparts. Regardless of the defect-state of the samples prior to testing, a size effect is apparent—where the yield strength increases as the sample size decreases. Since dislocation starvation and the single-arm-source mechanisms cannot explain a size effect on yield strength in dislocation-free samples, we investigate the dislocation nucleation mechanisms controlling the size effect through careful experimental observations and molecular statics simulations. We find that intrinsic or extrinsic symmetry breakers such as surface defects, edge roundness, external sample shape, or a high vacancy concentration can influence dislocation nucleation, and thus contribute to the size effect on yield strength in initially dislocation-free samples.

Confined Growth of High-quality Single-Crystal MAPbBr3 by Inverse Temperature Crystallization for Photovoltaic Applications

Organic–inorganic hybrid halide perovskite solar cells are promising for next-generation thin-film solar cells, demonstrating power conversion efficiency exceeding 25%. In particular, single-crystal perovskite materials are estimated to possess superior optoelectronic properties that can further enhance the efficiency. However, fabricating thin single-crystal perovskite for a light-absorber layer remains challenging. In this study, a 40-µm-thick single-crystalline MAPbBr3 perovskite is fabricated by inverse temperature crystallization (ITC) with a selective seed-transfer technique. By using a separate seed growth process and a seed-transfer process, a 16.23-mm2-large single domain high-quality single-crystalline MAPbBr3 perovskite can be grown without additional nucleation. The grown single-crystal MAPbBr3 exhibits a low surface roughness of 0.51 nm and low trap density of 7.61 × 108 cm−3. We also fabricate solar cells with single-crystalline MAPbBr3 using a glass substrate coated with SnO2 and indium-tin-oxide thin films. The single-crystal MAPbBr3-based solar cells demonstrate a power conversion efficiency of 4.31%.

Comparative Analysis Reveals the Metabolic Characteristics of Astringent Seeds of Chinese Fir (Cunninghamia lanceolata (Lamb) Hook) during Astringent Compounds Accumulation Stages

Research Highlights: The present study firstly reported the metabolic dynamics of astringent seed, a special type of abortion in Chinese fir, during the astringent material stages. The results provide a reference for further study on its occurrence mechanism and enrich the understanding of the plant seed developmental physiology. Background and Objectives: Astringent seed is a type of abortive phenomenon in Chinese fir, which significantly reduces the yield and quality of elite seeds for its high-incidence and indistinguishableness in seed orchard. Embryo defects can be observed in the astringent seed, accompanied with rapid accumulation of secondary metabolites. However, types of those metabolites in astringent seed, dynamic changes during seed growth process, and different accumulative characteristics compared to germinable seed have not been explained. Materials and Methods: Astringent and germinable seed samples were collected at four stages aim to determine the differences in their metabolic patterns. A liquid chromatography-mass spectrometry (LC-MS) detection was used to generate the raw metabolic peaks. Bioinformatics statistical strategies were used to further investigation. Results: A total of 421 metabolites were screened and 112 metabolites were identified as the different expressive metabolites including 68 up-regulated and 44 down-regulated metabolites. Those different expressive metabolites were grouped into 26 classes. Flavone, flavonol, and amino acid derivatives compounds were the most varied metabolites. Four subcategories which could represent the diverse basic expressive patterns or accumulative activity in different sample groups were further clustered. Moreover, pathways related to biosynthesis/degradation/metabolism of flavonoid-like compounds, amino acid/nucleotides derivatives, zeatin, and IAA were clearly enriched. Conclusions: Significant metabolic differences were observed across and between astringent and germinable seeds 105 d after pollination. Massive accumulation of flavonoids-like compounds, significant reduction of amino acids/nucleotides and their derivatives, and the abnormal expression of phytohormones, lipids and other secondary metabolites are the main metabolic characteristics in astringent seeds.

Silica coating of iron oxide magnetic nanoparticles by reverse microemulsion method and their functionalization with cationic polymer P(NIPAm-co-AMPTMA) for antibacterial vancomycin immobilization

Iron oxide nanoparticles (IONPs) have previously been demonstrated as a platform for antibiotic drug carriers in biomedicine. In this work, a new approach has been envisioned to improve the colloidal stability of IONPs in aqueous media as well as drug-nanoparticle interactions through the surface modification with poly[N-isopropylacrylamide-co-(3-acrylamidopropyl) trimethylammonium chloride], P(NIPAm-co-AMPTMA) via a multi-step process. Briefly, surface modification of oleic acid coated nanoparticles (Fe3O4-OA), (prepared by co-precipitation), was carried out with tetraethylorthosilicate (TEOS) using an inverse microemulsion method and subsequently with reactive vinyl group (−CH = CH2) containing [3-(methacryloyloxy)propyl] trimethoxysilane (MPS) by a seed growth process. The MPS containing silica coated iron oxide particles (Fe3O4/SiO2), were used as seed for copolymerization of NIPAm and AMPTMA to obtain the thermally sensitive magnetic nanocomposites (MNCs), Fe3O4/SiO2/P(NIPAm-co-AMPTMA). Analysis of the prepared Fe3O4/SiO2/P(NIPAM-co-AMPTMA) nanocomposites showed well defined magnetic core and a modified silica shell with organic polymer. Changes in temperature resulted in alteration of the hydrodynamic diameter and zeta potential. To evaluate practical use of the MNCs, an antibacterial vancomycin was immobilized, and bacterial growth inhibition demonstrated the potential of these nanocomposites for application in biomedicine.

Regulated Crystallization of FASnI3 Films through Seeded Growth Process for Efficient Tin Perovskite Solar Cells

Although rapid progress has been made in tin-based perovskite solar cells (PSCs), the inferior film qualities of the solution-processed perovskites always lead to poor reproducibility and instability. Herein, we present a simple seeded growth (SG) approach to obtain high-quality tin-based perovskite films with preferred crystal orientation, large grain sizes, and fewer apparent grain boundaries. High-quality tin-based perovskite films fabricated through this SG process could greatly reduce the nonradiative recombination centers and inhibit the oxidation of Sn2+. Using formamidinium tin tri-iodide (FASnI3) perovskites, the SG-PSCs exhibit a much improved efficiency from 5.37% (control) to 7.32% with all improved photovoltaic parameters. Moreover, this SG strategy is easily applicable to other tin-based perovskite compositions. The PSC based on methylammonium (MA) doped mixed-cation perovskite (FA0.75MA0.25SnI3) exhibited a power conversion efficiency (PCE) of 8.54% with an improvement of 19.3% in the photovoltaic performance, making it a general approach for achieving efficient tin-based PSCs.