Perovskite Precursor Research Articles

Stabilization of Perovskite Solar Cells by a Universal Dilution Strategy: The Crystallization Control of Blade-Coating.

Solvent engineering is one of the most effective strategies to control perovskite film quality, which directly affects the performance of perovskite solar cells (PSCs). Here, we introduce volatile acetonitrile (ACN) into the traditional solvent system (i.e., N,N-dimethylformamide and N-methyl-2-pyrrolidone) to dilute the perovskite precursors from 1.43 M to lower concentration (0.6-0.8 M). The dilution strategy can effectively improve the stability of the precursor solution and maintain similar film quality and device performance as those with high solution concentration (1.43 M). Notably, the devices with low-concentration precursors (0.6-0.8 M) show efficiency of 20.85% and improved long-term (>1000 h) storage stability compared to the device with high precursor concentration by blade-coating. Meanwhile, the material cost can be reduced by more than 50% when diluting to 0.6-0.8 M. These results demonstrate a universal dilution method which can provide guidance for the research and development of low-cost and high stability PSCs.

Synergistic Effect of Ionic Liquid and Embedded QDs on 2D Ferroelectric Perovskite Films with Narrow Phase Distribution for Self-Powered and Broad-Band Photodetectors.

2D layered metal halide perovskites (MHPs) are a potential material for fabricating self-powered photodetectors (PDs). Nevertheless, 2D MHPs produced via solution techniques frequently exhibit multiple quantum wells, leading to notable degradation in the device performance. Besides, the wide band gap in 2D perovskites limits their potential for broad-band photodetection. Integrating narrow-band gap materials with perovskite matrices is a viable strategy for broad-band PDs. In this study, the use of methylamine acetate (MAAc) as an additive in 2D perovskite precursors can effectively control the width of the quantum wells (QWs). The amount of MAAc greatly affects the phase purity. Subsequently, PbSe QDs were embedded into the 2D perovskite matrix with a broadened absorption spectrum and no negative effects on ferroelectric properties. PM6:Y6 was combined with the hybrid ferroelectric perovskite films to create a self-powered and broad-band PD with enhanced performance due to a ferro-pyro-phototronic effect, reaching a peak responsivity of 2.4 A W-1 at 940 nm.

Encapsulating Halide Perovskite Quantum Dots in Metal–Organic Frameworks for Efficient Photocatalytic CO2 Reduction

Halide perovskite has shown great potential in photocatalysis owing to its diversity, suitable energy band alignment, rapid charge transfer, and excellent optical properties. However, poor stability, especially under humid conditions, hinders their practical application in photocatalysis. In this work, we report the encapsulation of inorganic–organic hybrid perovskite QDs into MIL-101(Cr) through an in situ growth strategy to prepare a series of MAPbBr3@MIL-101(Cr) (MA = CH3NH3+) composites. The perovskite precursors, i.e., MABr and PbBr2, were successively introduced into the pores of MOF, where the perovskite quantum dots were self-assembled in the confined environment. In photocatalytic CO2 reduction, 11%MAPbBr3@MIL-101(Cr) composite displayed the best performance among the composites with a total CO and CH4 yield of 875 μmol g−1 in 9 h, which was 8 times higher than that of the pure MAPbBr3. Such high gas production efficiency could be maintained for 78 h at least without structural and morphologic decomposition. The remarkable stability and catalytic activity of composites are mainly due to the synergistic effect and improved electron transfer between MAPbBr3 and MIL-101(Cr). Moreover, these composites revealed a novel mechanism, showing switched CH4 selectivity with the controlling of the perovskite location and contents. Those with perovskites encapsulated in the mesopores of MIL-101(Cr) were more preferential for CO production, while those with perovskites encapsulated in both meso- and micropores could produce CH4 dominantly.

Additive engineering for efficient wide-bandgap perovskite solar cells with low open-circuit voltage losses.

High-performance wide-bandgap (WBG) perovskite solar cells are used as top cells in perovskite/silicon or perovskite/perovskite tandem solar cells, which possess the potential to overcome the Shockley-Queisser limitation of single-junction perovskite solar cells (PSCs). However, WBG perovskites still suffer from severe nonradiative recombination and large open-circuit voltage (Voc) losses, which restrict the improvement of PSC performance. Herein, we introduce 3,3'-diethyl-oxacarbo-cyanine iodide (DiOC2(3)) and multifunctional groups (C=N, C=C, C-O-C, C-N) into perovskite precursor solutions to simultaneously passivate deep level defects and reduce recombination centers. The multifunctional groups in DiOC2(3) coordinate with free Pb2+ at symmetric sites, passivating Pb vacancy defects, effectively suppressing nonradiative recombination, and maintaining considerable stability. The results reveal that the power conversion efficiency (PCE) of the 1.68eV WBG perovskite solar cell with an inverted structure increases from 18.51% to 21.50%, and the Voc loss is only 0.487V. The unpackaged device maintains 95% of its initial PCE after 500h, in an N2 environment at 25°C.

γ‐Valerolactone Enabling Spontaneously Inhibited Iodide Oxidation for High‐Quality Perovskite Single Crystal Fabrication

AbstractThe iodide precursor oxidation has persistently plagued solution grown iodine‐based perovskite single crystals (IPSCs) that inevitably introduce undesirable triiodide ion (I3−) defects and severely hindering crystal quality, despite IPSCs having garnered remarkable progress in multifarious photoelectronic applications. In this work, the spontaneously inhibited iodide oxidation is discovered in an eco‐friendly solvent, γ‐Valerolactone (GVL), and demonstrates a universal solution approach for fabricating high‐quality IPSCs. Compared to the routine γ‐Butyrolactone (GBL) system, GVL provides a lowered growth temperature and a significantly broadened inverse temperature operation window, thereby improving the theoretical utilization rate of perovskite precursors up to 88.6%. More importantly, due to its higher open‐ring hydrolysis energy, GVL can spontaneously inhibit the iodide precursors oxidation without any additional reductant and therefore effectively prevent the forming I3− defects. Typically, the as‐fabricated MAPbI3 single crystal possesses an extremely low trap density of 3.57 × 108 cm−3 and a high carrier mobility‐lifetime (µτ) product of 2.74 × 10−3 cm2 V−1, which enables its photodetection capabilities to be on a par with the state‐of‐art MAPbI3 single crystal photodetectors. This work paves an efficacious and green pathway for high‐quality IPSC fabrication toward advanced optoelectronic utilizations.

Columnar Macrocyclic Molecule Tailored Grain Cage to Stabilize Inorganic Perovskite Solar Cells with Suppressed Halide Segregation

AbstractSolidifying the soft lattice of all‐inorganic mixed‐halide perovskites is of great importance to restrain the notorious halide segregation under persistent light illumination. Herein, a multifunctional columnar macrocyclic molecule additive, namely cucurbituril into perovskite precursor to enhance the crystallization and reduce the defect density in the final perovskite film is introduced. Based on the theoretical calculation and simulation, the cucurbituril molecule with a strong double‐ended negatively‐charged cavity surrounded by terminated oxygen atoms not only coordinates with dangling Pb2+ ions to form host‐guest complexation but also induces an electric dipole field at perovskite grain boundary to effectively repel the iodide ion migration from the inside grain to the defective boundary, significantly suppressing the halide segregation and improving the device performance. As a result, the carbon‐based, all‐inorganic CsPbI2Br solar cell achieves an enhanced efficiency of 15.59% with great tolerance to environmental stresses. These findings provide new insights into the development of a novel passivation strategy with macrocyclic molecules for making high‐efficiency and stable perovskite solar cells.

Suppressed Defects by Functional Thermally Cross-Linked Fullerene for High-Efficiency Tin-Lead Perovskite Solar Cells.

Mixed tin-lead (Sn-Pb) perovskites have attracted the attention of the community due to their narrow bandgap, ideal for photovoltaic applications, especially tandem solar cells. However, the oxidation and rapid crystallization of Sn2+ and the interfacial traps hinder their development. Here, cross-linkable [6,6]-phenyl-C61-butyric styryl dendron ester (C-PCBSD) is introduced during the quenching step of perovskite thin film processing to suppress the generation of surface defects at the electron transport layer interface and improve the bulk crystallinity. The C-PCBSD has strong coordination ability with Sn2+ and Pb2+ perovskite precursors, which retards the crystallization process, suppresses the oxidation of Sn2+, and improves the perovskite bulk and surface crystallinity, yielding films with reduced nonradiative recombination and enhanced interface charge extraction. Besides, the C-PCBSD network deposited on the perovskite surface displays superior hydrophobicity and oxygen resistance. Consequently, the devices with C-PCBSD obtain PCEs of up to 23.4% and retained 97% of initial efficiency after 2000h of storage in a N2 atmosphere.

Efficient bifacial semi-transparent perovskite solar cells via a dimethylformamide-free solvent and bandgap engineering strategy

Semi-transparent perovskite solar cells (ST-PSCs) featuring high performance and light transmittance are highly desirable for building integrated photovoltaic (BIPV) applications. However, it is challenging to balance the device efficiency and transmittance due to the trade-off between light-harvesting capability and transparency of the perovskite active layer. Herein, we demonstrate a simple solvent- and bandgap-engineering strategy to effectively enhance film transparency of (FAPbI3)0.85(MAPbBr3)0.15 perovskite while simultaneously preserving its decent light-harvesting capability. N-methyl-2-pyrrolidone (NMP) as the solvent of the perovskite precursor effectively confines the growth of perovskite grains, leading to reduced light-scattering and enhanced average visible transparency (AVT) of the perovskite layer (over 28 %). Meanwhile, the NMP solvent promotes the growth of highly crystalline perovskite films with excellent light-harvesting capability, largely benefiting from stable intermediate adducts due to its intrinsic nature as a coordinative Lewis base. Further bandgap engineering of the perovskite light adsorber (1.6 eV) leads to the design of highly efficient bifacial ST-PSCs, achieving a power conversion efficiency of 15.58 % when illuminated from the conductive glass side and 9.67 % from the top electrode side, both under 1 sun illumination. The best-performing devices also show great promise for indoor applications with an efficiency of 25 % under 1000 lux indoor light illumination.

Small molecule induced interfacial defect healing to construct inverted perovskite solar cells with high fill factor and stability

Chemical defects at the surface and grain boundaries of perovskite crystals cause deterioration of conversion efficiency and stability of perovskite solar cells (PSCs). In this study, a multifunctional additive, 5-fluoro-2-pyrimidine carbonitrile (FPDCN) molecule, is added into the perovskite precursor solution in order to passivate the uncoordinated Pb2+ by the cyanogen (–CN) group and pyrimidine N in FPDCN. Interestingly, fluorine (F) atoms interact with FA+ to form hydrogen bonds, which could regulate the perovskite crystallization process for the formation of high-quality perovskite crystals. Besides, the F atoms in FPDCN increase the water contact angle of perovskite films. As a result, the carrier extraction and transport in the perovskite film are significantly enhanced, and the non-radiative recombination is suppressed. The corresponding devices achieve a champion photovoltaic conversion efficiency (PCE) of 20.7 % and a fill factor (FF) of over 83 %. The device based on FPDCN shows long-term stability under a high-humidity atmospheric environment by maintaining 85 % of the initial efficiency after aging of 700 h in the glove box. This study provides a simple and convenient method to prepare stable and efficient PSCs by optimizing the perovskite precursor solution.

Efficient Perovskite Light‐Emitting Diodes Processed with Green Solvents Enabling a Wide Antisolvent Time Window

AbstractGreen solvent processing of perovskite light‐emitting diodes (PeLEDs) is a necessity for their future commercialization. However, the almost insoluble nature of perovskites in most green solvents strongly impedes the progress of green solvent‐processed PeLEDs. Here, a novel green solvent triethylene glycol (TEG) is used as the processing solvent for perovskites. TEG has better solubility for perovskite precursors than most reported green solvents. Moreover, it is found that the low vapor pressure of TEG solvent and stable precursor solution render a much wider time window for the so‐called antisolvent treatment than that of perovskite precursor solution in commonly dimethyl sulfoxide. High‐quality perovskite film can be readily synthesized with the antisolvent treatment at a time window of 70–100 s, and the resultant green PeLEDs demonstrate nearly identical light‐emitting efficiencies. Together with further interface modification, the optimized green PeLEDs processed with TEG exhibit an external quantum efficiency of 20.4% and a maximal luminance over 38000 cd m−2. It is the first successful attempt to fabricate high‐efficiency PeLEDs utilizing green solvent and is enlightening for the development of high‐performance PeLEDs prepared with eco‐friendly solvents.

Synergistic effects of the physical modification and chemical passivation enabling efficient perovskite solar cells

Inverted perovskite solar cells (IPSCs) with poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) as hole transport materials exhibit superior stability and low-temperature processibility. However, the hydrophobicity of PTAA renders it difficult to prepare high-quality perovskite films due to the low wettability of perovskite precursor solutions, resulting in poor crystallization of perovskites and undesirable interface properties of PTAA/perovskites. Herein, a porous layer of Al2O3 nanoparticles functionalized using 2-thenoylacetonitrile (2-T-OACN) molecules is incorporated into the PTAA/perovskite interface. The physical adhesion of Al2O3 nanoparticles on the PTAA layer could enhance the surface wettability for perovskite precursor solutions, resulting in uniform perovskite films being realized on the PTAA layer. Meanwhile, 2-T-OACN adsorbed on the Al2O3 nanoparticles could form C=O··· Pb2+ and C≡N ···Pb2+ coordination interactions with the bottom surface of perovskites, thus passivating the defects at the PTAA/perovskite interface. Moreover, the electron-rich thiophene groups in 2-T-OACN molecules further promote interfacial charge carrier transport and thus significantly lower the interfacial recombination. Consequently, the IPSCs show a high efficiency of 23.3 %, which is largely improved compared with that of 19.4 % efficiency for control IPSCs. The synergistic strategy of the physical modification and chemical passivation provides a feasible approach for modulating the crystallization of perovskites and buried interface properties for IPSCs.

In situ reconstruction of proton conductive electrolyte from self-assembled perovskite oxide-based nanocomposite for low temperature ceramic fuel cells

In the development of low temperature solid oxide fuel cells (LT-SOFCs), also called ceramic fuel cells, the lack of highly conductive and the high manufacturing cost of dense electrolyte materials severely delay their wide development. In this work, we depart from the classic substitution approach to achieve sufficient ionic conduction (0.01 S cm−2 level at temperature ≥600 °C), a superionic conductive electrolyte material was obtained from a self-assembled hybrid oxide that was derived from the perovskite oxide precursor through alkali metal ion substitution. Moreover, the hybrid oxide was further in-situ reconstructed into a nanocomposite of oxide/carbonate-hydroxide under fuel cell condition. The nanocomposite possesses dominated proton conductivity as verified by the benefited hydration effect, versatile oxygen ionic blocking cell experiment, and concentration cell investigation. Specifically, an outstanding ionic conductivity of 0.185 S cm−1 and an excellent peak power density of 1012 mW cm−2 were demonstrated at 550 °C under an typical H2/air atmosphere. This research offers a rational design strategy to achieve low temperature, high-performance semiconductor-based functional composite electrolytes for efficient and sustainable energy conversion in SOFC technology.

Synchronized crystallization in tin-lead perovskite solar cells

Tin-lead halide perovskites with a bandgap near 1.2 electron-volt hold great promise for thin-film photovoltaics. However, the film quality of solution-processed Sn-Pb perovskites is compromised by the asynchronous crystallization behavior between Sn and Pb components, where the crystallization of Sn-based perovskites tends to occur faster than that of Pb. Here we show that the rapid crystallization of Sn is rooted in its stereochemically active lone pair, which impedes coordination between the metal ion and Lewis base ligands in the perovskite precursor. From this perspective, we introduce a noncovalent binding agent targeting the open metal site of coordinatively unsaturated Sn(II) solvates, thereby synchronizing crystallization kinetics and homogenizing Sn-Pb alloying. The resultant single-junction Sn-Pb perovskite solar cells achieve a certified power conversion efficiency of 24.13 per cent. The encapsulated device retains 90 per cent of the initial efficiency after 795 h of maximum power point operation under simulated one-sun illumination.

Crown Ethers with Different Cavity Diameters Inhibit Ion Migration and Passivate Defects toward Efficient and Stable Lead Halide Perovskite Solar Cells.

Organic-inorganic hybrid metal halide perovskite solar cells have been considered as one of the most promising next-generation photovoltaic technologies. Nevertheless, perovskite defects and Li+ ionic migration will seriously affect the power conversion efficiency and stability of the formal device. Herein, we designed two crown ether derivatives (PC12 and PC15) with different cavity diameters, which selectively bind to different metal cations. It is found that PC15 in perovskite precursor solution can actively regulate the nucleation and crystallization processes and passivate the uncoordinated Pb2+ ions, while PC12 at the interface between the perovskite layer and hole-transporting layer can effectively inhibit the migration of Li+ ions and reduce nonradiative recombination losses. Therefore, PC12 and PC15 can act as "lubricant" and defect passivators, as well as inhibitors of ion migration, when they are synergistically applied at the surface and bulk of perovskite layer. Consequently, the optimized device achieved a champion efficiency of 24.8% with significantly improved humidity, thermal, and light stability.

Effects of hydrazine compounds as additives on the characteristics of organic-inorganic hybrid lead-tin perovskite photovoltaic device

Lead-tin perovskite solar cells (Pb-Sn PSCs) are a more environmentally friendly alternative to the mainstream lead-based PSCs, but their development has been hampered by their instability due to the strong tendency of the Sn2+ constituent to oxidize. This study examines the effects of three types of hydrazine compound—phenylhydrazine hydrochloride (PH•HCl), 4-fluorophenylhydrazine hydrochloride (FPH•HCl), and 1-[2,5-bis(trifluoromethyl)phenyl]hydrazine hydrochloride (BTFMPH•HCl)—as additives to Pb-Sn perovskite precursor solutions on the stability and performance of Pb-Sn PSC devices, taking advantages of the hydrazine functional group’s ability to suppress oxidation of Sn2+, and of the hydrophobicity provided by the phenyl structure and/or fluorine (F) contents of the selected compounds. All of the three additives significantly improved the stability of the resultant Pb-Sn PSC devices, with the additives containing more F contents (BTFMPH•HCl > FPH•HCl > PH•HCl) showing slightly greater improvements. The PH•HCl additive markedly enhanced the power conversion efficiency (PCE) while reducing the hysteresis ratio of the PSC devices thanks to its multifaceted effects including improving morphology, reducing non-radiative losses, alleviating recombination defects, and enhancing charge-carrier mobility of the Pb-Sn perovskite layer, as elucidated by a series of photo-luminescence and electrical characterizations. Both the BTFMPH•HCl and FPH•HCl additives slightly degraded the device PCE due to their poorer resultant perovskite morphology, which was attributed to their lower affinity with the perovskite as a result of their F contents. Our results provide useful insights in selecting and designing hydrazine-based additives for PSC.

Synergistic effects of MOF 545 and inorganic additives synchronously for enhanced performance of low-cost carbon-based perovskite solar cells

Perovskite solar cells (PSCs) hold significant promise for the future of renewable energy, with their commercial viability highly anticipated. However, their limited long-term stability, mainly due to degradation from moisture, humidity, elevated temperatures, and UV-A light exposure, remains a significant obstacle. This study addresses these challenges by employing a multifaceted approach involving additive engineering and surface passivation. A novel method was used to synthesize CZTS nanoparticles, which were incorporated as an additive within the perovskite precursor solution. Additionally, MOF 545 was successfully integrated into the perovskite precursor solution, and a CdS layer was deposited at the ETL/perovskite interface. XRD analysis revealed that the combined addition of MOF 545 and CZTS enhanced the perovskite's crystallinity and surface morphology, leading to an increase in grain size and a reduction in grain boundary defects. Furthermore, these additives effectively restricted Pb2+ ion migration within the perovskite absorber layer. The champion cell, incorporating all three additives, achieved a notable power conversion efficiency (PCE) of 10.32 %, representing a significant 70.58 % increase compared to the pristine PSC. The use of additive-treated cells demonstrated improved thermal stability compared to untreated cells, as confirmed through stress testing. These results highlight the potential of additive engineering to significantly enhance the performance and stability of PSCs. Further exploration and optimization of synergistic additive combinations to achieve even greater performance enhancements and long-term stability in PSCs can pave the way for their successful commercialization.

Enhanced cation interaction in perovskites for efficient tandem solar cells with silicon.

To achieve the full potential of monolithic perovskite/silicon tandem solar cells, crystal defects and film inhomogeneities in the perovskite top cell must be minimized. We discuss the use of methylenediammonium dichloride as an additive to the perovskite precursor solution, resulting in the incorporation of in situ-formed tetrahydrotriazinium (THTZ-H+) into the perovskite lattice upon film crystallization. The cyclic nature of the THTZ-H+ cation enables a strong interaction with the lead octahedra of the perovskite lattice through the formation of hydrogen bonds with iodide in multiple directions. This structure improves the device power conversion efficiency (PCE) and phase stability of 1.68 electron volts perovskites under prolonged light and heat exposure under 1-sun illumination at 85°C. Monolithic perovskite/silicon tandems incorporating THTZ-H+ in the perovskite photo absorber reached a 33.7% independently certified PCE for a device area of 1 square centimeter.

Spiro-OMeTAD Anchoring perovskite for gradual homojunction in stable perovskite solar cells

The role of interface energetics-modification in interface-defect passivation and optimal interface energy-level matching is assumed to be a crucial aspect. Enhancing the performance and durability of perovskite solar cells (PSCs) can be achieved through this strategy. Here, spiro-OMeTAD [2,2′,7,7′-tetrakis (N, N-di-p-methoxyphenylamine)-9,9′-spirobifluorene] has been pipetted onto the spinning perovskite precursor film via a chlorobenzene anti-solvent strategy. It is found that spiro-OMeTAD serves as not only the filler at grain boundaries, but also the coverage on perovskite’s grain, and then forms the gradual homojunction interface from perovskite to spiro-OMeTAD hole transport layer, which can make spiro-OMeTAD anchor perovskite via the reaction between Pb2+ and C-O groups to decrease the interface barrier and obtain the optimal interface energy-level match between them for hole −migration and −collection. Moreover, these fillers or coverages can prevent moisture invading perovskite. Consequently, the counterpart PSC achieves a champion efficiency of 24.46 %, and has retained more than 88 % of the initial efficiency after 224 days of storage.

Crystallinity Control and Strain Release in Wide-Bandgap Perovskite Film via Seed-Induced Growth for Efficient Photovoltaics.

The seed method stands out as a straightforward and efficient approach for fabricating high-performance perovskite solar cells (PSCs). In this study, we propose the utilization of an antisolvent as an additive to induce crystal seeding, thereby facilitating the growth of wide-bandgap perovskite grains. Specifically, we introduce three commonly used antisolvents─ethyl acetate (EA), isopropanol (IPA), and chlorobenzene (CB)─directly into the perovskite precursor solution to generate perovskite seeds, which serve to promote subsequent nucleation. This antisolvent-crystal seeding method (ACSM) results in increased grain sizes, reduced film defects, and overall improved film quality. Consequently, the power conversion efficiencies (PCEs) of 1.647 eV PSCs with EA, IPA, and CB additives are recorded at 19.86%, 20.61%, and 20.45%, respectively, surpassing that of the reference device with a PCE of 18.83%. Furthermore, the stability of the PSCs prepared through ACSM is notably enhanced. Notably, PSCs optimized with IPA retain 75% of the original PCE after being stored in ambient air conditions (25 °C, RH ∼ 15%) for 30 days, better than the CB-added (64%) and the EA-added devices (53%), while the reference devices only retain 31% of the initial PCE. Moreover, even after continuous thermal annealing at 50 °C for 200 h, IPA-assisted devices demonstrate the best stability, followed by those with CB and EA, with the reference exhibiting the poorest stability.

Fluorinated Naphthalene Diimides as Buried Electron Transport Materials Achieve Over 23% Efficient Perovskite Solar Cells.

Naphthalene diimides (NDI) are widely serving as the skeleton to construct electron transport materials (ETMs) for optoelectronic devices. However, most of the reported NDI-based ETMs suffer from poor interfaces with the perovskite which deteriorates the carrier extraction and device stability. Here, a representative design concept for editing the peripheral groups of NDI molecules to achieve multifunctional properties is introduced. The resulting molecule 2,7-bis(2,2,3,3,4,4,4-heptafluorobutyl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone (NDI-C4F) incorporated with hydrophobic fluorine units contributes to the prevention of excessive molecular aggregation, the improvement of surface wettability and the formation of strong chemical coordination with perovskite precursors. All these features favor retarding the perovskite crystallization and achieving superior buried interfaces, which subsequently promote charge collection and improve the structural compatibility between perovskite and ETMs. The corresponding PSCs based on low-temperature processed NDI-C4F yield a record efficiency of 23.21%, which is the highest reported value for organic ETMs in n-i-p PSCs. More encouragingly, the unencapsulated devices with NDI-C4F demonstrate extraordinary stability by retaining over 90% of their initial PCEs after 2600 h in air. This work provides an alternative molecular strategy to engineer the buried interfaces and can trigger further development of organic ETMs toward reliable PSCs.