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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,405 records · Page 78
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Composition‐Conditioning Agent for Doped Spiro‐OMeTAD to Realize Highly Efficient and Stable Perovskite Solar Cells

Abstract The doped Spiro‐OMeTAD hole transport layer (HTL) formed using the lithium bis(trifluoromethane) sulfonimide salt and 4‐tert‐butylpyridine with phenethylammonium iodide surface treatment on a perovskite film has continuously dominated the record power conversion efficiencies (PCEs) of perovskite solar cells (pero‐SCs). However, unstable HTL compositions and iodide salts can cause severe device degradation. In this study, an HTL composition‐conditioning agent (CCA), Spiro‐BD‐2OEG, is designed, which contains a Spiro‐OMeTAD‐like backbone, functional pyridine units, and oligo (ethylene glycol) chains. This finely designed CCA presents good miscibility with Spiro‐OMeTAD and its dopants and acts as a conditioning agent through weak bond interactions. As a result, the CCA‐regulated HTL shows a pinhole‐free and smooth morphology with enhanced Spiro‐OMeTAD ordering and improves dopant stability. In addition, the gradient‐distributed CCA in the HTL can narrow the energy level offset with the valence band of the perovskite. The resultant pero‐SCs exhibit an excellent PCE of 24.19% without any interface treatment and weak size dependence. A remarkable PCE of 22.63% is obtained even for a 1.004‐cm 2 device. Importantly, the strategy shows good universality and significantly promotes the long‐term stability of the pero‐SCs based on the classical doped Spiro‐OMeTAD.

Chemistry↗
DOE OSTI2021

Janus Nanocages of Platinum-Group Metals and Their Use as Effective Dual-Electrocatalysts

Janus nanocages with distinctive platinum-group metals on the outer and inner surfaces can naturally catalyze at least two different reactions. In this work, we report a general method based on successive deposition and then selective etching for the facile synthesis of such nanocages. Herein, we have fabricated 11 different types of Janus nanocages characterized by a uniform size and well-defined {100} facets, together with porous, ultrathin, asymmetric walls up to 1.6 nm thick. When tested as dual-electrocatalysts toward oxygen reduction and evolution reactions, the Janus nanocages based on Pt and Ir exhibited superior activities depending on the thickness and relative position of the metal layer. Density functional theory studies suggest that the alloy composition and surface structure of the nanocages both play important roles in enhancing the electrocatalytic activities by modulating the stability of key reaction intermediates.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Tuning the Properties of Lignin‐Derived Deep Eutectic Solvents for Biomass Processing

Lignin-derived deep eutectic solvents (DESs) have been investigated as sustainable green media for biomass processing. However, the properties and processability of DESs have not been fully understood with the chemical structures of their constituents for biomass fractionation. Here, in this article, the properties of the phenolic DESs are discussed with different numbers of functional groups, such as –OCH 3 and –CHO in their hydrogen bond donor (HBD) structures. The formation of DES is significantly related to the hydrogen bond between its constituents, identified by nuclear magnetic resonance (NMR) analysis and density functional theory calculation (DFT). Lower viscosity and net basicity of DES are achieved with fewer –OCH 3 on HBD structures, resulting in enhanced processability and fractionation efficiency. The thermal stability of the DES is also influenced by the –OCH 3 and –CHO of HBD, as indicated by its onset temperature. The recyclability of the phenolic DES is confirmed by the fractionation performance of the recycled DES. Understanding the structural impacts of DES constituents on the properties and performance is crucial for designing solvents in biorefinery applications.

Ryu, Jiae [State University of New York (SUNY), Sy↗
DOE OSTI2025

Mechanistic Transformation of CuI Nanoparticles Into Oxidation‐Resistant 2D Copper Nanoplates

Unconventional phase transformations reveal new crystallization mechanisms, yet direct observation of such pathways during nanoscale solution-phase synthesis remains challenging. This study uncovers an atypical growth process in which thermodynamically stable CuI nanoparticles (NPs) transform into high-energy 2D Cu plates. Using a combination of in situ transmission electron microscopy, ex situ structural analysis, and density functional theory calculations shows that the formation of structural defects induced by hexadecylamine and chloride ions facilitates the transformation by promoting surface iodine vacancies. The resulting Cu{111} nanoplates, with ultrathin thicknesses (≈4 nm) and exceptionally high aspect ratios (≈450), display enhanced oxidation resistance and long-term stability under ambient conditions. This resistance is attributed to the close-packed {111} facets, which suppress chemical oxidation even after extended exposure to air over 100 days. These findings provide new insights into non-classical crystallization pathways in metal nanomaterials and suggest a versatile approach for preparing oxidation-resistant, structurally defined Cu nanostructures.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Quantification of grain rotation in bulk nanostructured copper via in situ heating white beam synchrotron X-ray diffraction

Grain rotation during microstructural relaxation under heating is conventionally studied extensively through transmission electron microscopy and simulations. However, there is a shortage in examining grain rotations at larger length and volume scales in bulk materials. It is critical to understand the thermal stability of bulk nanostructured metals, since those enhanced mechanical properties have been well recognized. Here, this study aimed to employ a white beam microdiffraction X-ray technique under in situ heating from 300 K to 1073 K at 12 K/min on a nanostructured copper processed by high-pressure torsion, yielding an initial grain size of ∼260 nm before the heating. Evaluation across a wide range of temperatures reveals transition temperatures associated with microstructural relaxation processes. By tracking separate Laue diffraction peaks stemming from individual grains, changes in their orientations can be estimated and quantified. This approach becomes particularly effective when the number of grains within the probed volume is reasonably small. At temperatures above 940 K, about 7.5 % of Cu grains are rotating at speeds of ∼2 × 10 –3 °/s. The radial direction of the disk specimen is found to be the preferred direction of grain rotation, with the rotation axis along the shear direction. Further analysis found no correlation between peak intensity and peak size, related to grain sizes and deviatoric strain, respectively, with rotation conditions or speed. These findings demonstrate that the diffraction technique utilizing white beam X-rays is a complementary and novel characterization tool for understanding microstructural evolution, especially in grain rotations, of bulk crystalline materials.

Grain orientation↗
DOE OSTI2026

A comparative study on cubic and tetragonal Ce-ZrO 2 supported Rh catalysts for N 2 O decomposition

Zirconium oxide (ZrO 2 ) exhibits strong synergy with cerium oxide (CeO 2 ), acting as a structural and electronic promoter during catalytic redox reactions. As a result, Ce-ZrO 2 composite oxides are widely used as supports in various catalytic systems. In our previous work, we demonstrated that the incorporation of Zr 4+ into the CeO 2 lattice significantly enhanced Rh dispersion, improved redox ability, and stabilized surface Rh species, which collectively boosted the de-N 2 O activity of Rh/Ce-ZrO 2 catalysts. Building on these findings, the present study emphasizes that the crystallographic phase of Ce-ZrO 2 , governed by the Ce/Zr ratio, plays a decisive role in tuning the physicochemical environment of Rh active sites and thereby optimizing catalytic performance. In conclusion, tailoring the Ce/Zr ratio to favor the cubic fluorite structure emerges as a promising strategy for the rational design of highly active and stable catalysts for N 2 O decomposition and potentially other redox-sensitive environmental applications.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Chemical bonding, phase stability and magnetic property in Sm 2 Fe 17 X 3 (X=H, C, N): A first-principles perspective

As a promising alternative to Nd–Fe–B magnets, the critical rare earth free Sm 2 Fe 17 X 3 (X = C, N) exhibits potential for high-performance magnets. However, their poor phase stability remains a major obstacle to developing bulk magnets. We investigated the phase stability and intrinsic magnetic properties of Sm 2 Fe 17 X 3 (X = H, C, N) using first-principles calculations and chemical bond analysis. The formation energies are negative, while the decomposition energies are −1.53, 0.348, and −0.74 eV per formula unit for X = H, C, and N, respectively, which is responsible for the weak thermal stability. Our chemical bond analysis reveals that the bonding asymmetry between Sm–X and Fe–X interactions creates local structural distortions and degrades the phase stability of Sm 2 Fe 17 X 3 . The project Crystal Orbital Hamilton Population (-pCOHP) analysis indicates that the Sm–X bonding remains positive up to the Fermi level, indicating stable bonding interactions. Here, in contrast, the Fe–X bonding becomes negative near the Fermi level, signifying anti-bonding contributions that reduce structural stability. Interstitial atoms X expand the lattice and enhance Fe magnetic moments, but Fe–X bonding suppresses neighboring Fe moments. Electron transfer from Sm to X modifies the valence state of Sm and the crystal field at the site, contributing to enhanced magnetocrystalline anisotropy in Sm 2 Fe 17 X 3 . Among the interstitial elements, carbon and nitrogen—with their larger atomic radius and higher electronegativity—induce greater lattice expansion and form stronger bonds with neighboring Sm and Fe atoms compared to hydrogen. Consequently, Sm 2 Fe 17 X 3 (X = C and N) exhibits better phase stability and significant improvement in magnetic properties.

Chemical bonding↗
DOE OSTI2025

Numerical framework for integrated additive manufacturing-compression molding (AM-CM) of thermoplastic composites

Additive manufacturing-compression molding (AM-CM) has emerged as a transformative technology in advanced composite manufacturing. Additive manufacturing (AM) offers high design flexibility and the ability to produce complex geometries with precisely aligned fibers in the preferred orientation. Compression molding (CM) enhances composite materials by providing excellent dimensional stability, reduced porosity, high production rates, and a smooth surface finish. Despite these advantages, extensive integrated analysis is required to optimize processing conditions for improved fiber orientation distribution (FOD) and porosity control. Here, this study develops a comprehensive numerical model to simulate the AM-CM manufacturing process. The model isolates the effects of both the AM and CM phases while also capturing their integration. Additionally, it accounts for heat transfer, temperature-dependent viscosity, and fiber orientation in the extruded fiber-filled polymer, accurately representing material behavior during processing. This approach enables the analysis of interactions between deposited beads of complex strand shapes and their interface regions after full compression. Moreover, the model predicts key parameters such as polymer flowability, fiber orientation, and temperature evolution in AM-CM parts. By optimizing processing conditions, it facilitates a controlled and predictable microstructure.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Hydroxypyridinone-based stabilization of Np(IV) enabling efficient U/Np/Pu separations in the Adapted PUREX process

The classical process to recover uranium (U) and plutonium (Pu) from used nuclear fuel using tributyl phosphate (TBP), namely the Plutonium Uranium Redox EXtraction (PUREX) process, is complicated by the persistent presence of neptunium (Np) and thus requires extra purification steps. The concept of Adapted PUREX seeks to achieve Np recovery by adjusting the valence of the metal more effectively, thereby controlling its behavior more precisely. This study introduces the use of an aqueous hydroxypyridinone chelator, 3,4,3-LI(1,2-HOPO) (abbreviated as HOPO), to dictate the behavior of Np for recovery and meanwhile simplify cumbersome reprocessing steps. The interactions between Np and HOPO were probed mechanistically by way of absorption spectrophotometry, in conjunction with cyclic voltammetry. UV–Vis-NIR spectra illustrated the reduction of NpO 2 2+ to Np 4+ , with a fast reaction rate. Cyclic voltammetry revealed quasi-reversible processes between the oxidized and reduced forms of the ligand and its Np complexes. The corresponding heterogeneous rate constants (k 0 ) were estimated from the peak-to-peak separation potentials (ΔE p ), at ~ 4 – 35 μm/s for both HOPO and NpHOPO, with scan rates of 0.01 – 0.4 V/s. Meanwhile, the electromotive force (E MF ) as well as the change of Gibbs free energy (ΔG) were assessed from the half-wave potential (E 1/2 ), demonstrating the completeness of NpO 2 2+ reduction to Np 4+ by HOPO. The cumulative formation constant of the resulting NpHOPO complex (logβ 101 ) was determined by metal competition titration to be 42.0 ± 0.6, corroborating the extraordinarily high affinity of HOPO to tetravalent metal ions. Here, the prowess of valence control by HOPO and the high stability of the formed complex resulted in enhanced separations of Np from U and of Pu from U, with a maximum separation factor of ~7000 for both, nearly 90- and 10300-fold higher, respectively, than the values obtained using conventional PUREX formulae.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2022

Delineating the Roles of Mn, Al, and Co by Comparing Three Layered Oxide Cathodes with the Same Nickel Content of 70% for Lithium-Ion Batteries

High-nickel layered oxides continue to prevail in the energy storage market as the frontmost cathode candidates for next-generation lithium-ion batteries. Demand and development of LiNi 1–x–y Mn x Co y O 2 (NMC) and LiNi 1–x–y Co x Al y O 2 (NCA) cathodes are rampantly increasing, particularly for the electric vehicle (EV) industry. However, the continued presence of cobalt in NMC and NCA cathodes raises global concerns due to geopolitical and ethical issues attributed to Co sourcing. We herein introduce a novel cobalt-free, high-nickel cathode LiNi 0.7 Mn 0.25 Al 0.05 O 2 (NMA70) and benchmark it against Co-containing LiNi 0.7 Mn 0.15 Co 0.15 O 2 (NMC70) as well as Co- and Al-free LiNi 0.7 Mn 0.3 O 2 (NM70) cathodes with equivalent 70% Ni contents that are all synthesized in-house. NMA70 displays a high initial C/10 capacity of 210 mA h g –1 , matching that of NMC70 in half cells with a cutoff voltage of 4.5 V. NMA70 also exhibits an impressive high-voltage full cell cycling performance with a cutoff voltage of 4.4 V with a nearly identical capacity retention of 83% compared to that of 82% for NMC70 after 300 cycles. Postmortem X-ray photoelectron spectroscopy (XPS), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and electron energy loss spectroscopy (EELS) analyses indicate a thinner cathode–electrolyte interface (CEI) developed in NMA70 compared to that in NM70 and unveil a more robust solid-electrolyte interface (SEI) passivation on the graphite anode among all samples. The benefits of Al doping are additionally highlighted with enhanced high-voltage CEI and thermal stabilities in NMA70. Furthermore, this work assesses the roles of Mn, Al, and Co to demonstrate both the practicality and feasibility of synthesizing cobalt-free, high-nickel cathodes that are promising alternatives to current NMC- and NCA-based cathodes.

25 ENERGY STORAGE↗
DOE OSTI2019

Probing Mg Migration in Spinel Oxides

Mg batteries utilizing oxide cathodes can theoretically surpass the energy density of current Li-ion technologies. The absence of functional devices so far has been ascribed to impeded Mg 2+ migration within oxides, which severely handicaps intercalation reactions at the cathode. Broadly, knowledge of divalent cation migration in solid frameworks is surprisingly deficient. In this paper, we present a combined experimental and theoretical study of Mg migration within three spinel oxides, which reveal critical features that influence it. Experimental activation energies for a Mg 2+ hop to an adjacent vacancy, as low as ~0.6 eV, are reported. These barriers are low enough to support functional electrodes based on the intercalation of M g2+ . Subsequent electrochemical experiments demonstrate that significant demagnesiation is indeed possible, but the challenges instead lie with the chemical stability of the oxidized states. Our findings enhance the understanding of cation transport in solid structures and renew the prospects of finding materials capable of high density of energy storage.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Unraveling pH-Dependent Changes in Adsorption Structure of Uranyl on Alumina (012)

Mitigating uranium transport in groundwater is imperative for ensuring access to clean water across the globe. Here, in situ resonant anomalous X-ray reflectivity is used to investigate the adsorption of uranyl on alumina (012) in acidic aqueous solutions, representing typical U VI concentrations of contaminated water near mining sites. The analyses reveal that U VI adsorbs at two distinct heights of 2.4-3.2 and 5-5.3 angstrom from the surface terminal oxygens. The former is interpreted as the mixture of inner-sphere and outer-sphere complexes that adsorb closest to the surface. The latter is interpreted as an outer-sphere complex that shares one equatorial H 2 O with the terminal surface oxygen. With increasing pH, we observe an increasing prevalence of these outer-sphere complexes, indicating the enhanced role of the hydrogen bond that stabilizes adsorbed uranyl species. Finally, the presented work provides a molecular-scale understanding of sorption of uranyl on Al-based-oxide surfaces that has implications for environmental chemistry and materials science.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Kinetic Understanding of Field-Induced Phase Transition from Tetragonal to Ferroelectric Orthorhombic Phase in Ferroelectric CeO 2 –HfO 2 –ZrO 2 Films

The ferroelectric properties and structural phase transition behaviors of fluorite-type CeO 2 −HfO 2 −ZrO 2 films were investigated. The epitaxial films on indium tin oxide (ITO) (111)/yttria-stabilized zirconia (YSZ) (111) substrates were grown through pulsed laser deposition at room temperature and subsequently heat-treated at 1000 °C under a N 2 gas flow. The crystalline phases and Curie temperatures of the films were investigated by X-ray diffraction. An increase in the Ce or Zr content in the films led to a higher crystallographic symmetry, such as orthorhombic or tetragonal. In addition, electrical characterization revealed that the orthorhombic films and some of the tetragonal films displayed ferroelectricity. This was due to the field-induced phase transition from the tetragonal to ferroelectric orthorhombic phase in the films, where the Curie temperatures were relatively low. The tetragonal metastable phase was kinetically frozen and could not change into the stable orthorhombic phase at such a low temperature. The critical electric field where the field-induced phase transition occurred was below 0.8 MV/cm, which was sufficiently small compared to the coercive field. These results evidence the kinetic driving force that causes a field-induced phase transition from the paraelectric tetragonal phase to the ferroelectric orthorhombic phase in HfO 2 -based ferroelectrics. They also enhance our understanding of the thermodynamic phase stabilities of HfO 2 -based material polymorphs.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Calcium Gradient-Doped LiNi 0.5 Mn 1.5 O 4 Cathode for Long Cycle Life Lithium-Ion Batteries

High-voltage spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) has attracted considerable attention as a cathode material for next-generation lithium-ion batteries due to its high operating voltage and intrinsically fast lithium-ion diffusion kinetics. However, the practical implementation of LNMO remains limited by its rapid capacity decay, primarily associated with bulk structural instability and parasitic interfacial reactions. To address these issues, we innovatively introduced calcium (Ca) as a dopant to enhance both the oxygen framework and surface stabilities of the LNMO crystal through gradient doping. Observations from the electronic microscopies, X-ray diffraction, and the elemental analysis confirmed that Ca is preferentially enriched at the particle surface, and a disordered crystal phase is preserved in the bulk in the gradient-doped LNMO cathodes. As cathodes in LIBs, the Ca gradient-doped (Ca gr) LNMO materials delivered formation capacities of ∼126−130 mAh/g and exhibited Coulombic efficiencies of 88−95%, which are consistently higher than those of the uniform-doped samples at the same doping level and undoped sample. Especially, the Ca gr 0.05 LNMO cathode demonstrated significantly improved rate capability with ∼113 mAh/g preserved at 10 C, while ∼92 mAh/g and ∼110 mAh/g for undoped and Ca uniform 0.05 LNMO, respectively, and excellent cycling stability, retaining ∼124.1 mAh/g (∼96.3% capacity retention) after 500 cycles. The analysis of cyclic voltammetry, differential capacity, and electrochemical impedance revealed that the excellent electrochemical performance is attributed to the structural and morphological advantages of gradient-doped LNMO cathodes with a disordered bulk structure for fast Li + diffusion and a Ca-enriched surface for minimizing the Mn dissolution.

25 ENERGY STORAGE↗
DOE OSTI2020

Comparison of Metal Adhesion Layers for Au Films in Thermoplasmonic Applications

If thermoplasmonic applications such as heat-assisted magnetic recording are to be commercially viable, it is necessary to optimize both thermal stability and plasmonic performance of the devices involved. In this work, a variety of different adhesion layers were investigated for their ability to reduce dewetting of sputtered 50 nm Au films on SiO 2 substrates. Traditional adhesion layer metals Ti and Cr were compared with alternative materials of Al, Ta, and W. Film dewetting was shown to increase when the adhesion material diffuses through the Au layer. An adhesion layer thickness of 0.5 nm resulted in superior thermomechanical stability for all adhesion metals, with an enhancement factor of up to 200X over 5 nm thick analogues. The metals were ranked by their effectiveness in inhibiting dewetting, starting with the most effective, in the order Ta > Ti > W > Cr > AI. Finally, the Au surface-plasmon polariton response was compared for each adhesion layer, and it was found that 0.5 nm adhesion layers produced the best response, with W being the optimal adhesion layer material for plasmonic performance.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Activation of Lattice and Adatom Oxygen by Highly Stable Ceria-Supported Cu Single Atoms

Requiring catalysts to be both active yet stable over long periods of time under variable reaction conditions including high and low temperatures is a daunting challenge due to the almost mutual exclusivity of these constraints. Using CO oxidation as a probe reaction, in this work we demonstrate that thermally stable single atom copper catalysts prepared by high temperature synthesis (atom trapping) on ceria can achieve this feat by allowing modulation of the Cu charge state through facile charge transfer between active site and support. This provides the catalysts with an ability to activate either lattice or adatom oxygen atoms, accessing additional reaction channels depending on the reaction conditions. Such adaptability allows dynamic response of catalysts enabling them to remain active under variable reaction conditions. The inherent stability of the catalyst arises from the enhanced strength of the Cu-O interactions from high temperature synthesis that exist even when Cu oxidation state varies, which retards sintering and deactivation. As we show here, one can circumvent the dilemma of designing catalysts that are simultaneously active and stable by matching the redox properties of the active site and support and establishing an environmental adaptability around the active sites.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Superconductivity and a van Hove singularity confined to the surface of a topological semimetal

The interplay between topology and superconductivity generated great interest in condensed matter physics. Here, we unveil an unconventional two-dimensional superconducting state in the Dirac nodal line semimetal ZrAs 2 which is exclusively confined to the top and bottom surfaces within the crystal's ab plane. As a remarkable consequence, we present the first clear evidence of a Berezinskii-Kosterlitz-Thouless (BKT) transition occurring solely on a material's surface-specifically, ZrAs 2 -unlike the inconsistent reports on PtBi 2 , CaAgP, and CaAg 1-x Pd x P. Furthermore, we find that these same surfaces also host a two-dimensional van Hove singularity near the Fermi energy. This leads to enhanced electronic correlations that contribute to the stabilization of superconductivity at the surface of ZrAs 2 . The'surface-confined nature of the van Hove singularity and associated superconductivity, realized for the first time, allows exploring the interplay between low-dimensional quantum topology and superconductivity in a bulk material without resorting to the superconducting proximity effect.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

Nanoscopic cross-grain cation homogenization in perovskite solar cells

Multiscale cation inhomogeneity has been a major hurdle in state-of-the-art formamidinium–caesium (FA–Cs) mixed-cation perovskites for achieving perovskite solar cells with optimal power conversion efficiencies and durability. Although the field has attempted to homogenize the overall distributions of FA–Cs in perovskite films from both plan and cross-sectional views, our understanding of grain-to-grain cation inhomogeneity and ability to tailor it—that is, spatially resolving the FA–Cs compositional difference between individual grains down to the nanoscale—are lacking. Here we reveal that as fundamental building blocks of a perovskite film, individual grains exhibit cationic compositions deviating from the prescribed ideal composition, severely limiting the interfacial optoelectronic properties and perovskite layer durability. This performance-limiting nanoscopic factor is linked to thermodynamic-driven morphological grooving, leading to a segmented surface landscape. At the grain triple junctions, grooves form nanoscale groove traps that hinder the mixing of solid-state cations across grains and thus retard inter-grain FA–Cs mixing. By rationally modulating the heterointerfacial energies, we reduced the depth of these nanoscale groove traps by a factor of three, significantly improving cation homogeneity. Perovskite solar cells with shallower nanoscale groove traps demonstrate enhanced power conversion efficiencies (25.62%) and improved stability under various standardized international protocols. In conclusion, our work highlights the significance of resolving surface nano-morphologies for homogeneous properties of perovskites.

77 NANOSCIENCE AND NANOTECHNOLOGY↗