Vacancy Defects Research Articles

A computational study of the structure of anion vacancy defects in the bulk and on the surfaces of ceria

Ceria is an important technological material that finds wide application as an oxygen storage component in heterogeneous oxidation catalysis. In these applications the removal of lattice oxygen results in two reduced Ce3+ centres whose location relative to the vacancy site has a profound influence on the vacancy formation energy. Here we present DFT calculations on the bulk and surface oxygen defect formation highlighting the distribution of structures that are thermally accessible in such a situation. We also demonstrate that the Ce3+ locations influence the barrier to oxygen anion migration.

Ultra‐Stable and Bright Pure‐Red Perovskite Nanocrystals for Backlit Displays

AbstractMetal halide perovskite nanocrystals (NCs) have emerged as an alternative to conventional phosphors for wide color gamut displays. However, the issues of poor stability and low emission efficiency of pure‐red CsPbBrxI3‐x NCs set an obstacle to their practical application. Herein, the synergistic effect of Mn doping and mesoporous SiO2 sealing is reported through in situ formation of Mn‐doped NCs into mesoporous SiO2 nanospheres (MnNCs@SiO2) to structurally and spatially stabilize the perovskite NCs for bright and stable pure‐red emitter. The large bonding energy of Mn‐halogen effectively suppresses the halide vacancy defects, prompting the highest photoluminescence quantum yield (PLQY) up to 84% (634 nm) among the pure‐red composite analogs. More importantly, the nanocrystal structure stability is fundamentally improved by the enhanced formation energy with Mn doping, together with the spatial isolation by SiO2 nanospheres. The MnNCs@SiO2 films exhibit impressive stabilities against high‐temperature heating, thermal cycle test, UV irradiation, water, and acid/alkali erosion, representing one of the most stable pure‐red perovskite emitters. By integrating fabricated all‐perovskite CsPbX3 single color conversion film into the liquid crystal display (LCD) modules, a wide color gamut of 128% of NTSC is achieved, enabling an excellent color rendition for high‐saturation object colors toward practical applications.

Adsorption and sensing performances of vacancy defects and Cu-embedded GaN/MoTe2 heterostructure for harmful gases: A DFT study

By utilizing density functional theory (DFT), we explore the adsorption and sensing performance of NO, NO2, SO2 and CO on intrinsic GaN/MoTe2 heterostructure, vacancy-defective GaN/MoTe2 heterostructures and Cu-embedded GaN/MoTe2 heterostructures, respectively. The results indicate that the VGa-GaN/MoTe2 heterostructure exhibits higher adsorption energy (yielding more negative values) for all four gases, demonstrating superior adsorption performance compared to the intrinsic system. Similarly, the Cu-GaN/MoTe2 heterostructure also improves the adsorption performance for nitrogen oxides. Meanwhile, the Cu-MoTe2/GaN heterostructure also significantly outperforms the intrinsic systems in terms of adsorption performance for the four harmful gases. Particularly, the Cu-MoTe2/GaN heterostructure has an adsorption energy of −2.22 eV for NO2 and a charge transfer amount of up to 0.72 e, indicating a strong chemical interaction between the adsorption system and gas molecules. Therefore, Cu-MoTe2/GaN is a potential ideal gas adsorption material. This work offers a theoretical foundation for transition metal-doped semiconductor heterostructures for future research.

Role of Vacancy Defects and Nitrogen Dopants for the Reduction of Oxygen on Graphene.

Disentangling the roles of nitrogen dopants and vacancy defects (VG) in metal-free carbon catalysts for the oxygen reduction reaction (ORR) ideally requires studying both the dopants and defects separately. Here, we systematically introduced nitrogen dopants and VGs via plasma treatment into the basal plane of monolayer graphene as a model carbon catalyst to investigate their specific roles in ORR catalysis. An increased defect density including dopants is positively associated with boosted ORR activity. Nitrogen dopants are responsible for an improved current via a 2e- pathway generating hydroperoxide, while VGs result in enhanced kinetics and water production. We therefore infer that VGs in graphene are responsible for the improved ORR kinetics, while nitrogen dopants majorly influence the selectivity of ORR reaction products. The nitrogen dopants without VGs lead to a higher overpotential compared with the pristine graphene. Instead of the attribution of the ORR active site to only nitrogen species in carbon materials, the improved ORR activity in nitrogen-doped carbon materials should be attributed to the active sites constituted of VGs, oxygen dopants, and nitrogen dopants. Through this work, we provide important insights into the intertwined roles of nitrogen and VGs as well as oxygen dopants in nitrogen-doped metal-free catalysts for a more efficient ORR.

Effect of strain on the photoelectric properties of molybdenum ditelluride under vacancy defects: a DFT investigation.

This study explores the impact of deformation on the electrical and optical characteristics of monolayer cadmium telluride (MoTe2) with vacancies, using the foundational principles of density functional theory. It was discovered that both strain and imperfections alter the electrical characteristics of monolayer MoTe2. Under VTe-MoTe2, a direct-to-indirect band-gap transition occurs. In DTe-MoTe2, the band-gap value reduces dramatically, the conduction band changes downward, and the carrier concentration rises. The DVTe-induced band gap state is closer to the Fermi energy level than the VTe-induced band gap state. In this paper, DTe-MoTe2 is chosen for tensile deformation. The results show that the band-gap value tends to decrease by increasing tensile deformation. When the stretching value reaches 10%, the lower bound of the conduction band and the top of the valence band overlap, and the system is converted from a semiconductor to a metal. Considering the density of states, the missing state MoTe2 is mainly contributed by the participation of Te-s, Te-p, and Mo-d orbitals. In terms of optical qualities, the absorption and reflection peaks are red-shifted and blue-shifted, respectively. It is hoped that these effects on the optoelectronic properties will be widely applied. In this study, we utilize the generalized gradient approximation plane-wave pseudopotential method, incorporating Perdew-Burke Ernzerhof (PBE) generalized functions and following the fundamental principles of the density functional theory framework. A 3 × 3 × 1 supercell was constructed as an undoped model based on a MoTe2 monolayer, which consists of 9 Mo atoms and 18 Te atoms. The vacuum flat plate was set to 15Å along the z-direction to avoid interactions between the monolayers. For electronic structure calculations, the energy cutoff was set to 450eV. Each model's computational process and structural optimization were carried out using the Monkhorst-Pack specialized K-point sampling approach. Crystal optimization computations used a 3 × 3 × 1 Monkhorst-Pack K-point grid for molybdenum ditelluride monolayers and a 9 × 9 × 1K-point grid for electronic system analysis, analyzing state density and optical characteristics, respectively. For the structural optimization, the convergence requirements for maximum force, maximum atom displacement, maximum stress, and energy change were defined at 0.03eV/Å, 0.001Å, 0.05 Gpa, and 1.0 × 10-5eV/atom, respectively.

Effect of laser-assisted irradiation on plasma electrolytic oxidation of titanium alloys: Arc spot evolution characteristics and photoelectric synergistic mechanisms

Laser irradiation can be employed as an auxiliary energy field to optimize functional plasma electrolytic oxidation (PEO) coatings. Herein, the mechanism of the effect of laser-assisted irradiation on the morphology and composition of ceramic coatings prepared by PEO of titanium alloys in electrolytes with sodium tetraborate-based is discussed from the perspective of plasma arc spot evolution and photoelectric synergistic effect. X-ray diffraction (XRD), transmission electron microscopy (TEM), Mott-Schottky (M-S), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to analyze the coating characteristics. The results showed that laser-assisted irradiation promoted the oxidation of the coatings, accelerated the conversion of the anatase phase to the rutile phase, reduced the oxygen vacancy defects and formed the "ant nest" porous microstructure. Monitoring of the voltage, electric field, and plasma discharge arc spot indicated that laser-assisted irradiation restricted the electric field diffusion on the anode surface, reduced the termination voltage, and significantly increased the intensity (maximum discharge percentage increased from 14.238 % to 20.358 %) and uniformity of distribution of the plasma discharge. Instantaneous photoresponse curves and electrochemical impedance spectroscopy confirmed that the PEO coatings exhibited fast and sustained photoelectric response under simultaneous laser irradiation, progressively enhanced with increasing laser irradiation energy. The photogenerated electrons excited by the semiconductor TiO2 coating under the simultaneous irradiation of laser can be used as the initial carriers of the electron avalanche, which induces the generation of a plasma on the surface of the anode and thus enhances the plasma discharge behavior, which is the fundamental reason for the optimization of the coating characteristics.

Natural Antioxidant Vitamin C Improves Photovoltaic Performance of Tin-Lead Mixed Perovskite Solar Cells.

The oxidation of Sn2+ can occur even after the completion of the perovskite crystallization in a low oxygen environment. Concerning this, the natural antioxidant vitamin C (VC) is introduced to the surface of Sn-Pb mixed perovskite using a postprocessing method to achieve the purpose of inhibiting Sn2+ oxidation and enhancing perovskite solar cells performance. The results indicate that the VC could effectively inhibit Sn2+ oxidation and heal the vacancy defects of the annealed perovskite film. Meanwhile, the introduction of VC significantly improves the morphology and crystalline quality of the perovskite films. After optimization, the highest power conversion efficiency of the VC-treated Sn-Pb mixed device increased to 20.44%. Moreover, the VC-treated unencapsulated device shows excellent long-term stability, retaining 75.3% of its initial efficiency after 800 h of aging in a N2 atmosphere, which is much higher than the 20.1% of the control device.

H+ implantation induced defects distribution in 4H-SiC single crystal film fabricated by Crystal-Ion-Slicing and its effects on electrical behavior: A multiple characterization study

The composite substrate of SiC single crystal films fabricated by Crystal-Ion-Slicing (CIS) is acknowledged as an excellent material platform for the realization of electronic devices with specific functions. In CIS technology, the transferred monocrystalline films can retain good monocrystalline quality close to the virgin monocrystalline quality, but the lattice damage caused by ion implantation and crystal cleavage is still not negligible. The distribution of H+ implantation induced defects is studied in this paper, according to which the transferred film can be divided into lattice distortion region, moderately damaged region and application region. The lattice distortion region has serious lattice defects and stacking faults, while the moderately damaged layer is dominated by high lattice stress and high density point defects. For application region, in addition to the defect morphology, its influence on the electrical behavior is also investigated, which indicate the defects are mainly vacancy defects introduced by the H+ penetration, which act as carrier traps and recombination centers in electronic behavior. The research work is helpful to further understand the microstructure and defect distribution of the films of various materials fabricated by the common technology CIS, and can provide a theoretical basis for further defect layer removal and defect repair.

Microscopic damage in eutectic SnPb alloy: First-principles calculations and experiments

This study aims to comprehensively elucidate the microscopic origins of damage in eutectic SnPb alloy through atomic-scale investigations, a crucial endeavor for enhancing the alloy’s properties and furthering the development of Pb-free solders. First-principles calculations based on density functional theory (DFT) were employed to examine the mechanical constants and defect formation energies of the Pb phase, the β-Sn phase, and potential Sn/Pb eutectic phases in the SnPb alloy. The Voigt-Reuss-Hill approximation was utilized to derive the mechanical parameters of the elastically stable structure in SnPb alloy, facilitating the prediction of its mechanical properties. The defect formation energy calculations revealed a higher difficulty in forming vacancy defects in the β-Sn phase compared to the Pb phase. This discrepancy can be attributed to the stronger interactions between Sn atoms, resulting in the formation of more stable Sn-Sn bonds, thereby impeding vacancy generation in the β-Sn phase. Furthermore, the Pb phase exhibited a tendency for Sn atoms to occupy octahedral interstitial sites, whereas in the β-Sn phase, Pb atoms tended to displace neighboring Sn atoms along the [110] orientation into adjacent interstitial sites and occupy their lattice positions. Experimental observations complemented these calculation findings, demonstrating significant Sn element presence, up to 27.22 at%, in the Pb-rich phase, with notable microvoid damage primarily concentrated within this region. This observation aligns with the conclusions drawn from first-principles calculations and unveils the microscopic origins of damage in eutectic SnPb alloys.

Eu-doped ZnO coatings prepared by spray pyrolysis for photocatalytic applications

The ZnO-Eu2O3 coatings immobilized on stainless steel foil were synthesized by a spray pyrolysis method using an inorganic salt, Zn(CH3COO)2·2H2O, and Eu2O3 nanopowder with different Zn/Eu ratios. The coatings were investigated by SEM, XRD, XPS, DRS, and photoluminescence analysis, and their photoactivity was studied in the degradation of two pollutants, lindane and methyl orange. The ZnO-Eu2O3 coatings were more photoactive than coatings containing only ZnO. Among the ZnO-Eu2O3 coatings, the photocatalyst with 2 wt% Eu2O3 showed the highest photoactivity for both pollutants. The incorporation of Eu3+ ions into the ZnO crystal lattice causes the appearance of oxygen vacancy defects and better charge separation in the ZnO-Eu2O3 coating. When the Eu2O3 concentration exceeds 2 wt%, the photoactivity decreases as additional centers for electron-hole pair recombination are created. It is shown that the main factor influencing the photoactivity of Eu-doped ZnO composite coatings is the amount of Eu3+ incorporated into the ZnO lattice.

Screening and comparison of 18 transition metal atoms doped to modulate the electrocatalytic synthesis of ammonia with multi-S vacancies MoS2: A study of density functional theory

Electrocatalytic nitrogen reduction reaction (NRR) represents a promising approach for the sustainable production of ammonia (NH3). However, current electrocatalysts exhibit limitations in terms of active sites, high reaction potential, and poor reaction selectivity. Consequently, there is a pressing need for the development of NRR electrocatalysts with high activity and selectivity under mild conditions. Among them, defect engineering and transition metal doping are two effective methods to improve the electronic structure of catalysts. In this paper, density functional theory was used to study the activity of electrocatalytic NRR on Molybdenum disulfide (MoS2) surfaces with 1–4 S vacancy numbers (VSx–MoS2, x = 1–4) and transition metal (TM)-doped VS3–MoS2 (TM@VS3–MoS2). Both VSx–MoS2 showed better structural stability, with S vacancy defects altering the electronic structure of the surface. As more Mo atoms were exposed on the surface of the structure, the adsorption of N2 gradually enhanced and the reaction was more inclined to undergo NRR. Further investigation of 18 TM-doped VS3–MoS2 revealed that the doping of Sc, Ti, V, Y, Zr and Nb atoms effectively inhibits the hydrogen precipitation reaction and reduced the energy of NH3 desorption, which contributed to the continuation of the reaction. Therefore, the improvement of MoS2 electrocatalytic NRR performance can be achieved by constructing S vacancies and TM doping to provide a better basis and reference for experimental exploration.

Enhanced photocatalytic H2O2 production through synergistic double-vacancy engineering in Z-scheme TiO2-x/g-C3N4-x heterojunction

The photocatalytic synthesis of hydrogen peroxide (H2O2) is an environmentally benign and sustainable approach. In this study, we have synthesized a TiO2-x/g-C3N4-x(A-TxCNx) photocatalyst with a Z-scheme heterojunction by introducing oxygen and nitrogen double vacancies through a one-step reduction process. The optimized A-TxCNx catalyst exhibited a superior H2O2 yield of 1131.59 μmol L–1h−1 under visible light, which is 5.85 times greater than that of the A-TCN catalyst. This enhancement is ascribed to the synergistic effects of the oxygen vacancies (Ov) and nitrogen vacancies (Nv) defects, which amplify light absorption, facilitate electron-hole pair separation, and augment the number of active sites on the catalyst surface. Density functional theory (DFT) calculations and energy band analysis were employed to elucidate the photocatalytic mechanism of A-TxCNx, revealing that H2O2 synthesis predominantly occurs through two consecutive reactions, enabled by the catalyst’s unique electronic structure and defect configuration. This study not only validates the exceptional photocatalytic performance of A-TxCNx but also provides valuable insights for the design and optimization of future photocatalysts aimed at sustainable H2O2 production.

Highly Crystalline Multivariate Prussian Blue Analogs via Equilibrium Chelation Strategy for Stable and Fast Charging Sodium-Ion Batteries.

Prussian blue analogs (PBAs) have been widely recognized as superior cathode materials for sodium-ion batteries (SIBs) owing to numerous merits. However, originating from the rapid crystal growth, PBAs still suffer from considerable vacancy defects and interstitial water, making the preparation of long-cycle-life PBAs the greatest challenge for its practical application. Herein, a novel equilibrium chelation strategy is first proposed to synthesize a high crystallinity (94.7%) PBAs, which is realized by modulating the chelating potency of strong chelating agents via "acid effect" to achieve a moderate chelating effect, forcefully breaking through the bottleneck of poor cyclic stability for PBAs cathodes. Impressively, the as-prepared highly crystalline PBAs represent an unprecedented level of electrochemical performance including ultra-long lifespan (10000 cycles with 86.32% capacity maintenance at 6Ag-1), excellent rate capability (82.0mAhg-1 at 6Ag-1). Meanwhile, by pairing with commercial hard carbon, the as-prepared PBAs-based SIBs exhibit high energy density (350Whkg-1) and excellent capacity retention (82.4% after 1500 cycles), highlighting its promising potential for large-scale energy storage applications.

High-temperature hydrogen sensor based on MOFs-derived Mn-doped In2O3 hollow nanotubes

Developing high-temperature hydrogen (H2) sensors with fast response speed is urgently demanded in harsh application environments, especially for chemical industries and the aerospace field. Herein, we have reported a facile strategy to synthesize Mn-doped In2O3 hollow nanotubes (Mn-In2O3) by solvothermal and annealing route using In-MOFs as precursors. The experimental results indicate that the obtained products possess hollow nanotube structures with plenty of holes and Mn doping greatly boosts the gas-sensing performance of In2O3-based sensors towards H2. In particular, the responses of 3 mol% Mn-In2O3 are 2.57 and 2.3 towards 50 ppm H2 at 360 °C and 400 °C, respectively, which are much higher than those of bare In2O3 hollow nanotubes. Besides, the sensor based on 3 mol% Mn-In2O3 exhibits a low limit of detection (25 ppb), excellent selectivity, rapid response/recovery speed (∼4 and ∼15 s@20 ppm), and excellent stability at high temperature (360 °C). Such enhancement of H2-sensing properties can be put down to the hollow structure derived from In-MOFs and abundant oxygen vacancy defects produced by Mn doping. The Mn-In2O3 hollow nanotubes could be regarded as promising materials for selectively detecting H2 in a wide range of concentrations.

In-grown and irradiation-induced Al and N vacancies in 100 keV H+ implanted AlN single crystals

We report positron annihilation results on in-grown and proton-irradiation-induced vacancy defects in AlN single crystals grown by physical vapor transport. The samples were irradiated with 100 keV H+ ions to varying fluences in the range of 5 × 1014 − 2 × 1018 ions cm–2. Doppler broadening of annihilation radiation was recorded in as-grown and irradiated samples with a slow positron beam with varying implantation energy. Doppler results combined with first principles theoretical calculations show that the 100 keV H+ irradiation introduces isolated VAl on the ion track and VN-rich vacancy clusters at the end of the ion range. The results suggest that the excess amount of detected VN originates from a high concentration of in-grown VN. So far, these defects have been considered to be unidentified negative ion-like defects in AlN.

Oxygen vacancy-engineered P-doped MoO3/Ce2Mo4O15 bimetallic heterojunction nanosheet array for enhanced oxygen evolution reaction

Surface oxygen vacancies in defective metals have the capacity to enhance oxygen evolution reaction (OER) activity but easily suffer from instability and deactivation in continuous electrocatalysts. Heterojunction engineering is important for achieving effective catalysis, but its simultaneous engineering remains a challenge. Therefore, it is necessary to develop an effective heterojunction catalyst to improve the electrocatalytic stability of defective metallic oxygen vacancies. In this work, we report a Ce, Mo bimetallic defective heterojunction P-MoO3/Ce2Mo4O15@NF-1 via a facile one-step hydrothermal method and annealing in a tube furnace. Bimetallic oxide heterojunctions offer several advantages over conventional single-metal heterojunctions, including stable structure, more active sites, faster rates of electron transfer, and less pollution of the environment. Meanwhile, P-doped catalyst could enhance the metallicity significantly. In addition, the prepared catalyst P-MoO3/Ce2Mo4O15@NF-1 showed extraordinary catalytic activity for OER in alkaline media. The overpotential and Tafel slope of the catalyst at a current density of 50 mA cm-2 were 270 mV and 87.27 mV dec‑1, respectively. It maintains an impressive balance between electrocatalytic activity and stability. This research explores the co-effects of Ce and Mo bimetallic oxide in defective electrocatalysts and also provides ideas for designing OER catalysts with defective metal heterojunctions.

Modified SnO2 Electron Transport Layer by One‐Step Doping with Histidine in Perovskite Solar Cells

Tin dioxide (SnO2), one of the best electron transport layer materials for perovskite solar cells (PSCs), has high electrical conductivity and low photocatalytic activity. However, the defects in its inside and surface result in nonradiative recombination at the SnO2/perovskite interface. Complex and time‐consuming passivation methods are not conducive to the commercialization of PSCs, and simple passivation strategies should be used to improve the photovoltaic performance of the devices. Herein, a facile and efficient method is proposed to simultaneously passivate the inside and surface defects by adding histidine (HIS) to SnO2 colloidal solution. This one‐step doping strategy also modulates carrier dynamics at the SnO2/perovskite interface. HIS reduces suspended hydroxyl groups, oxygen vacancies, and uncoordinated Sn4+ defects on the surface of SnO2, as well as uncoordinated Pb2+ and halogen vacancy defects at the buried interface of perovskite. Surprisingly, HIS can prevent perovskite from decomposition to form PbI2, which further decomposes to photoactive metallic Pb0 and I, causing ion migration in PSC. As a result, the PSC efficiency has significantly improved 23.11% after HIS doping. The efficiency of unencapsulated device with HIS is 94% of the primary efficiency after storage in relative humidity = 70 ± 5% for 1000 h.

Enhanced Thermal and Photostability of Perovskite Solar Cells by a Multifunctional Eu (III) Trifluoromethanesulfonate Additive

AbstractPerovskite solar cells (PSCs) have witnessed a meteoric rise in device performance. However, maintaining photostability, particularly under thermal stress, remains a challenge due to defect formation in the perovskite layer. This study introduces europium (III) trifluoromethanesulfonate [Eu(OTF)3] as a multifunctional additive in two‐step processed perovskite films, significantly improving the performance and high‐temperature photostability of n‐i‐p PSCs. Density function theory (DFT) calculations reveal that the OTF− anion strongly coordinates with Pb2+, effectively inhibiting iodine vacancy defect formation. The addition of Eu(OTF)3 promotes perovskite grain growth to ≈2 µm and enhances film crystallinity. PSCs with a structure of ITO/SnO2/perovskite/PDCBT/NiOx/Au achieve a champion power conversion efficiency (PCE) of 23.8%. Under 85 ± 5 °C and 1 sun illumination at an open circuit in ambient air, the PSCs with Eu(OTF)3 retain 82% of their initial PCE after aging for 1500 h.

The Effect of Oxygen Vacancy Defects on the Structure and Electrochemical Behaviors of LiMn0.65Fe0.35PO4 Cathode

The presence of oxygen vacancy defects significantly impacts the crystal structure and electrochemical attributes of phosphate cathodes. In this investigation, LiMn0.65Fe0.35PO4 materials with varying levels of oxygen vacancy defects were synthesized via hydrogen plasma-induced reduction. It was observed that the content of oxygen vacancy defects on the crystal surface increased proportionately with the rise in hydrogen (H2) flow rate. Notably, the LMFP-3 sample, prepared with an H2 flow rate of 10 ml min−1, demonstrated superior electrochemical performance, characterized by a 159.7 mAh g−1 discharge capacity at 0.1 C and a remarkable 99.8% capacity retention at 5 C after 200 cycles. This enhancement in electrochemical performance is attributed to the improved intrinsic conductivity of the LiMn0.65Fe0.35PO4 material due to the presence of oxygen vacancy defects. However, it is important to note that an excessively high H2 flow rate can lead to the formation of Fe2P impurities, which hinder lithium ion (Li+) diffusion. Furthermore, theoretical calculations conducted using density functional theory provide a rational explanation for the observed improvement in electronic conductivity. The introduction of oxygen vacancy defects results in a significant reduction in the Band gap, which is highly beneficial for enhancing the intrinsic conductivity of the LiMn0.65Fe0.35PO4 materials.

Defect Passivation and Crystallization Regulation for Efficient and Stable Formamidinium Lead Iodide Solar Cells with Multifunctional Amidino Additive.

Amidino-based additives show great potential in high-performance perovskite solar cells (PSCs). However, the role of different functional groups in amidino-based additives have not been well elucidated. Herein, two multifunctional amidino additives 4-amidinobenzoic acid hydrochloride (ABAc) and 4-amidinobenzamide hydrochloride (ABAm) are employed to improve the film quality of formamidinium lead iodide (FAPbI3) perovskites. Compared with ABAc, the amide group imparts ABAm with larger dipole moment and thus stronger interactions with the perovskite components, i.e., the hydrogen bonds between N…H and I- anion and coordination bonds between C = O and Pb2+ cation. It strengthens the passivation effect of iodine vacancy defect and slows down the crystallization process of α-FAPbI3, resulting in the significantly reduced non-radiative recombination, long carrier lifetime of 1.7 µs, uniformly large crystalline grains, and enhances hydrophobicity. Profiting from the improved film quality, the ABAm-treated PSC achieves a high efficiency of 24.60%, and maintains 93% of the initial efficiency after storage in ambient environment for 1200 hours. This work provides new insights for rational design of multifunctional additives regarding of defect passivation and crystallization control toward highly efficient and stable PSCs.