Synergistic defect passivation and strain compensation toward efficient and stable perovskite solar cells

Rational interface engineering is essential for minimizing interfacial nonradiative recombination losses and enhancing device performance.Herein,we report the use of bidentate diphenoxybenzene(DPOB)isomers as surface modifiers for perovskite films.The DPOB molecules,which contain two oxygen(O)atoms,chemically bond with undercoordinated Pb^(2+) on the surface of perovskite films,resulting in compression of the perovskite lattice.This chemical interaction,along with physical regulations,leads to the formation of high-quality perovskite films with compressive strain and fewer defects.This compressive strain-induced band bending promotes hole extraction and transport,while inhibiting charge recombination at the interfaces.Furthermore,the addition of DPOB will reduce the zero-dimensional(OD) Cs_4PbBr_6 phase and produce the two-dimensional(2D) CsPb_(2)Br_5 phase,which is also conducive to the improvement of device performance.Ultimately,the resulting perovskite films,which are strain-released and defect-passivated,exhibit exceptional device efficiency,reaching 10.87% for carbon-based CsPbBr_(3) device,14.86% for carbon-based CsPbI_(2)Br device,22,02% for FA_(0.97)Cs_(0.03)PbI_(3) device,respectively.Moreover,the unencapsulated CsPbBr_(3) PSC exhibits excellent stability under persistent exposure to humidity(80%) and heat(80℃) for over 50 days.

Role of self-assembled molecules’anchoring groups for surface defect passivation and dipole modulation in inverted perovskite solar cells

Inverted perovskite solar cells have gained prominence in industrial advancement due to their easy fabrication,low hysteresis effects,and high stability.Despite these advantages,their efficiency is currently limited by excessive defects and poor carrier transport at the perovskite-electrode interface,particularly at the buried interface between the perovskite and transparent conductive oxide(TCO).Recent efforts in the perovskite community have focused on designing novel self-assembled molecules(SAMs)to improve the quality of the buried interface.However,a notable gap remains in understanding the regulation of atomic-scale interfacial properties of SAMs between the perovskite and TCO interfaces.This understanding is crucial,particularly in terms of identifying chemically active anchoring groups.In this study,we used the star SAM([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)as the base structure to investigate the defect passivation effects of eight common anchoring groups at the perovskite-TCO interface.Our findings indicate that the phosphonic and boric acid groups exhibit notable advantages.These groups fulfill three key criteria:they provide the greatest potential for defect passivation,exhibit stable adsorption with defects,and exert significant regulatory effects on interface dipoles.Ionized anchoring groups exhibit enhanced passivation capabilities for defect energy levels due to their superior Lewis base properties,which effectively neutralize local charges near defects.Among various defect types,iodine vacancies are the easiest to passivate,whereas iodine-substituted lead defects are the most challenging to passivate.Our study provides comprehensive theoretical insights and inspiration for the design of anchoring groups in SAMs,contributing to the ongoing development of more efficient inverted perovskite solar cells.

Enhancing the Performance of Perovskite Light-Emitting Diodes via Synergistic Effect of Defect Passivation and Dielectric Screening

Metal halide perovskites,particularly the quasi-two-dimensional perovskite subclass,have exhibited considerable potential for next-generation electroluminescent materials for lighting and display.Nevertheless,the presence of defects within these perovskites has a substantial influence on the emission efficiency and durability of the devices.In this study,we revealed a synergistic passivation mechanism on perovskite films by using a dual-functional compound of potassium bromide.The dual functional potassium bromide on the one hand can passivate the defects of halide vacancies with bromine anions and,on the other hand,can screen the charged defects at the grain boundaries with potassium cations.This approach effectively reduces the probability of carriers quenching resulting from charged defects capture and consequently enhances the radiative recombination efficiency of perovskite thin films,leading to a significant enhancement of photoluminescence quantum yield to near-unity values(95%).Meanwhile,the potassium bromide treatment promoted the growth of homogeneous and smooth film,facilitating the charge carrier injection in the devices.Consequently,the perovskite light-emitting diodes based on this strategy achieve a maximum external quantum efficiency of~21%and maximum luminance of~60,000 cd m^(-2).This work provides a deeper insight into the passivation mechanism of ionic compound additives in perovskite with the solution method.

Unraveling abnormal buried interface anion defect passivation mechanisms depending on cation-induced steric hindrance for efficient and stable perovskite solar cells

Although ionic liquids(ILs)have been widely employed to heal the defects in perovskite solar cells(PSCs),the corresponding defect passivation mechanisms are not thoroughly understood up to now.Herein,we first reveal an abnormal buried interface anion defect passivation mechanism depending on cationinduced steric hindrance.The IL molecules containing the same anion([BF4]^(-))and different sizes of imidazolium cations induced by substituent size are used to manipulate buried interface.It was revealed what passivated interfacial defects is mainly anions instead of cations.Theoretical and experimental results demonstrate that the large-sized cations can weaken the ionic bond strength between anions and cations,and facilitate the interaction between anions and SnO2as well as perovskites,which is conducive to interfacial defect passivation and ameliorating interfacial contact.It can be concluded that interfacial chemical interaction strength and defect passivation effect are positively correlated with the size of cations.The discovery breaks conventional thinking that large-sized modification molecules would weaken their chemical interaction with perovskite.Compared with the control device(21.54%),the device based on 1,3-Bis(1-adamantyl)-imidazolium tetrafluoroborate(BAIMBF4)with maximum size cations achieves a significantly enhanced efficiency of 23.61%along with much increased moisture,thermal and light stabilities.

Defect passivation by nontoxic biomaterial yields 21% efficiency perovskite solar cells

Defect passivation is one of the most important strategies to boost both the efficiency and stability of perovskite solar cells(PSCs).Here,nontoxic and sustainable forest-based biomaterial,betulin,is first introduced into perovskites.The experiments and calculations reveal that betulin can effectively passivate the uncoordinated lead ions in perovskites via sharing the lone pair electrons of hydroxyl group,promoting charge transport.As a result,the power conversion efficiencies of the p-i-n planar PSCs remarkably increase from 19.14%to 21.15%,with the improvement of other parameters.The hydrogen bonds of betulin lock methylamine and halogen ions along the grain boundaries and on the film surface and thus suppress ion migration,further stabilizing perovskite crystal structures.These positive effects enable the PSCs to maintain 90%of the initial efficiency after 30 days in ambient air with 60%±5%relative humidity,75%after 300 h aging at 85℃,and 55%after 250 h light soaking,respectively.This work opens a new pathway for using nontoxic and low-cost biomaterials from forest to make highly efficient and stable PSCs.

Simultaneously enhanced moisture tolerance and defect passivation of perovskite solar cells with cross-linked grain encapsulation

The grain surfaces(film surface and grain boundary)of polycrystalline perovskite films are vulnerable sites in solar cells since they pose a high defect density and initiate the degradation of perovskite absorber.Achieving simultaneously defect passivation and grain protection from moisture is crucial for the viability of perovskite solar cells.Here,an in situ cross-linked grain encapsulation(CLGE)strategy that improves both device stability and defect passivation is reported.Cross-linkable semiconducting small molecules are mixed into the antisolvent to uniformly form a compact and conducting cross-linked layer over the grain surfaces.This cross-linked coating layer not only passivates trap states and facilitates hole extraction,but also enhances the device stability by preventing moisture diffusion.Using the CLGE strategy,a high power conversion efficiency(PCE)of 22.7%is obtained in 1.55-eV bandgap planar perovskite solar cells.The unencapsulated devices with CLGE exhibit significantly enhanced device stability again moisture and maintain>90%of their initial PCE after shelf storage under ambient condition for over10,000 h.

Simultaneous passivation of bulk and interface defects through synergistic effect of anion and cation toward efficient and stable planar perovskite solar cells

Bulk and interface carrier nonradiative recombination losses impede the further improvement of power conversion efficiency(PCE)and stability of perovskite solar cells(PSCs).It is highly necessary to develop multifunctional strategy to minimize surface and interface nonradiative recombination losses.Herein,we report a bulk and interface defect passivation strategy via the synergistic effect of anions and cations,where multifunctional potassium sulphate(K_(2)SO_(4))is incorporated at SnO_(2)/perovskite interface.We find that K^(+)ions in K_(2)SO_(4)diffuse into perovskite layer and suppress the formation of bulk defects in perovskite films,and the SO_(4)^(2-)ions remain located at interface via the strong chemical interaction with SnO_(2)layer and perovskite layer,respectively.Through this synergistic modification strategy,effective defect passivation and improved energy band alignment are achieved simultaneously.These beneficial effects are translated into an efficiency increase from 19.45%to 21.18%with a low voltage deficit of0.53 V mainly as a result of boosted open-circuit voltage(V_(oc))after K_(2)SO_(4)modification.In addition,the K_(2)SO_(4)modification contributes to ameliorated stability.The present work provides a route to minimize bulk and interface nonradiative recombination losses for the simultaneous realization of PCE and stability enhancement by rational anion and cation synergistic engineering.

Defect passivation through electrostatic interaction for high performance flexible perovskite solar cells

The light weight,good bending resistance and low production cost make flexible perovskite solar cells(PSCs)good candidates in wearable electronics,portable charger,remote power,and flying objects.High power conversion efficiency(PCE)plays a crucial role on obtaining the high mass specific power of flexible devices.However,the performance for flexible PSCs is still having a large room to be improved.Here,we added the 2-amino-5-cyanopyridine(ACP)molecule with a polar electron density distribution in the perovskite precursor solution to improve the performance of flexible PSCs.The cyano groups with electron-withdrawing ability are expected to passivate positively charged point defects,while amines with electron donating ability are expected to passivate negatively charged point defects in perovskite films.Thanks to the effective passivation of defects at the grain boundary and surface of perovskite films,the PCE of flexible PSCs is obviously increased from 16.9%to 18.0%.These results provide a universal approach to improve performance of flexible PSCs by healing the defects in perovskite films through electrostatic interactions.

Defect passivation with potassium trifluoroborate for efficient spray-coated perovskite solar cells in air

Defects as non-radiative recombination centers hinder the further efficiency improvements of perovskite solar cells(PSCs).Additive engineering has been demonstrated to be an effective method for defect passivation in perovskite films.Here,we employed(4-methoxyphenyl)potassium trifluoroborate(C_(7)H_(7)BF_(3)KO)with and K+functional groups to passivate spray-coated(FAPbI_(3))_(x)(MAPbBr_(3))_(1-x) perovskite and eliminate hysteresis.It is shown that the F of can form hydrogen bonds with the H atom in the amino group of MA+/FA+ions of perovskite,thus reducing the generation of MA+/FA+vacancies and improving device efficiency.Meanwhile,K+and reduced MA+/FA+vacancies can inhibit ion migration,thereby eliminating hysteresis.With the aid of C_(7)H_(7)BF_(3)KO,we obtained hysteresis-free PSCs with the maximum efficiency of 19.5%by spray-coating in air.Our work demonstrates that additive engineering is promising to improve the performance of spray-coated PSCs.

High efficiency CZTSSe solar cells enabled by dual Ag-passivation approach via aqueous solution process

Ag substitution in Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)is a promising way to mitigate Cu/Zn related defects,electrostatic fluctuations and Shockley-Read-Hall(SRH)recombination centers.However,high performance ACZTSSe solar cells are generally demonstrated with more Ag amounts and strenuous fabrication processes,which are not ideal when using cheap constituent materials CZTSSe.To reduce the Ag amount(2%-3%),local Ag substitutions into CZTSSe at front(F),back(B)and dual front/back(FB)were proposed.Experimental results revealed that F-passivation effectively reduced the Cu/Zn related defects and further limits the interface/bulk recombination whereas B-passivation improved the grain growth at the back interface and further allows enhanced transport of charge carriers.By employing the dual Agpassivation approach,the final ACZTSSe device parameters were significantly improved and remarkable power conversion efficiency(PCE)of 12.43%was achieved with eco-friendly aqueous solution process.

Efficient Semi‑Transparent Wide‑Bandgap Perovskite Solar Cells Enabled by Pure‑Chloride 2D‑Perovskite Passivation

Wide-bandgap(WBG)perovskite solar cells suffer from severe non-radiative recombination and exhibit relatively large opencircuit voltage(V_(OC))deficits,limiting their photovoltaic performance.Here,we address these issues by in-situ forming a well-defined 2D perovskite(PMA)_(2)PbCl_(4)(phenmethylammonium is referred to as PMA)passivation layer on top of the WBG active layer.The 2D layer with highly pure dimensionality and halide components is realized by intentionally tailoring the side-chain substituent at the aryl ring of the post-treatment reagent.First-principle calculation and single-crystal X-ray diffraction results reveal that weak intermolecular interactions between bulky PMA cations and relatively low cation-halide hydrogen bonding strength are crucial in forming the well-defined 2D phase.The(PMA)_(2)PbCl_(4)forms improved type-I energy level alignment with the WBG perovskite,reducing the electron recombination at the perovskite/hole-transport-layer interface.Applying this strategy in fabricating semi-transparent WBG perovskite solar cells(indium tin oxide as the back electrode),the V_(OC)deficits can be reduced to 0.49 V,comparable with the reported state-of-the-art WBG perovskite solar cells using metal electrodes.Consequently,we obtain hysteresis-free 18.60%-efficient WBG perovskite solar cells with a high V_(OC)of 1.23 V.

New Carbon Nitride C_(3)N_(3) Additive for Improving Cationic Defects of Perovskite Solar Cells

Due to the loss of organic amine cations and lead ions in the structure of the iodine-lead methylamine perovskite solar cell,there are a large number of defects within the film and the recombination loss caused by grain boundaries,which seriously hinder the further improvement of power conversion efficiency and stability.Herein,a novel carbon nitride C_(3)N_(3) incorporated into the perovskite precursor solution is a multifunctional strategy,which not only increases the light absorption strength,grain size,and hydrophobicity of the perovskite film,but also effectively passivates the bulk and interfacial defects of perovskite and verified by the first-principles density functional theory calculations.As a result,the efficiency and stability of perovskite solar cells are improved.The device with 0.075 mg mL^(-1) C_(3)N_(3) additive delivers a champion power conversion efficiency of 19.91%with suppressed hysteresis,which is significantly higher than the 18.16% of the control device.In addition,the open-circuit voltage of the modified device with the maximum addition as high as 1.137 V is 90.96% of the Shockley–Queisser limit(1.25 V).Moreover,the power conversion efficiency of the modified device without encapsulation can maintain nearly 90% of its initial value after being stored at 25℃ and 60% relative humidity for 500 h.This work provides a new idea for developing additives to improve the power conversion efficiency and stability of perovskite solar cells.

Sodium Diffuses from Glass Substrates through P1 Lines and Passivates Defects in Perovskite Solar Modules

Most thin-film photovoltaic modules are constructed on soda-lime glass(SLG)substrates containing alkali oxides,such as Na_(2)O.Na may diffuse from SLG into a module's active layers through P1 lines,an area between a module's constituent cells where the substrate-side charge transport layer(CTL)is in direct contact with SLG.Na diffusion from SLG is known to cause several important effects inⅡ-Ⅵand chalcogenide solar modules,but it has not been studied in perovskite solar modules(PSMs).In this work,we use complementary microscopy and spectroscopy techniques to show that Na diffusion occurs in the fabrication process of PSMs.Na diffuses vertically inside P1 lines and then laterally from P1 lines into the active area for up to 360 pm.We propose that this process is driven by the high temperatures the devices are exposed to during CTL and perovskite annealing.The diffused Na preferentially binds with Br,forming Br-poor,l-rich perovskite and a species rich in Na and Br(Na-Br)close to P1 lines.Na-Br passivates defect sites,reducing non-radiative recombination in the perovskite and boosting its luminescence by up to 5×.Na-Br is observed to be stable after 12 weeks of device storage,suggesting long-lasting effects of Na diffusion.Our results not only point to a potential avenue to increase PSM performance but also highlight the possibility of unabated Na diffusion throughout a module's lifetime,especially if accelerated by the electric field and elevated temperatures achievable during device operation.

Boosting efficiency and stability of 2D alternating cation perovskite solar cells via rational surface-modification: Marked passivation efficacy of anion

Two-dimensional(2D) alternating cation(ACI) perovskite surface defects,especially dominant iodine vacancies(V_Ⅰ) and undercoordinated Pb^(2+),limit the performance of perovskite solar cells(PVSCs).To address the issue,1-butyl-3-methylimidazolium trifluoro-methane-sulfonate(BMIMOTF) and its iodide counterpart(BMIMI) are utilized to modify the perovskite surface respectively.We find that BMIMI can change the perovskite surface,whereas BMIMOTF shows a nondestructive and more effective defect passivation,giving significantly reduced defect density and suppressed charge-carrier nonradiative recombination.This mainly attributes to the marked passivation efficacy of OTF-anion on V_Ⅰ and undercoordinated Pb^(2+),rather than BMIMI^(+) cation.Benefiting from the rational surface-modification of BMMIMOTF,the films exhibit an optimized energy level alignment,enhanced hydrophobicity and suppressed ion migration.Consequently,the BMIMOTF-modified devices achieve an impressive efficiency of 21.38% with a record open-circuit voltage of 1.195 V,which is among the best efficiencies reported for 2D PVSCs,and display greatly enhanced humidity and thermal stability.

Dramatic reduction in dark current ofβ-Ga_(2)O_(3) ultraviolet photodectors viaβ-(Al_(0.25)Ga_(0.75))_(2)O_(3) surface passivation

Solar-blind ultraviolet photodetectors with metal-semiconductor-metal structure were fabricated based onβ-(Al_(0.25)Ga_(0.75))_(2)O_(3)/β-Ga_(2)O_(3) film grown by metal-organic chemical vapor deposition.It was known that various surface states increase dark current and a large number of defects can hinder the transport of carriers,resulting in low switching ratio and low responsivity of the device.In this work,β-(Al_(0.25)Ga_(0.75))_(2)O_(3) films are used as surface passivation materials.Owning to its wide band gap,we obtain excellent light transmission and high lattice matching withβ-Ga_(2)O_(3).We explore the change and mechanism of the detection performance of theβ-Ga_(2)O_(3) detector afterβ-(Al_(0.25)Ga_(0.75))_(2)O_(3) surface passivation.It is found that under the illumination with 254 nm light at bias 5 V,theβ-(Al_(0.25)Ga_(0.75))_(2)O_(3)/β-Ga_(2)O_(3)photodetectors show dark current of just 18 pA and high current on/off ratio of 2.16×10^(5).The dark current is sharply reduced about 50 times after passivation of theβ-Ga_(2)O_(3) surface,and current on/off ratio increases by approximately 2 times.It is obvious thatβ-Ga_(2)O_(3) detectors withβ-(Al_(0.25)Ga_(0.75))_(2)O_(3) surface passivation can offer superior detector performance.

A-site assisted perovskite crystallization via ion-exchange MOFs for high efficient and stable perovskite solar cells

Here,a novel strategy is proposed targeting the volatility of A-site cations and the disordered arrangement of perovskite grains through employing Cs~+contained metal-organic frameworks In-aip(Cs)obtained by ion-exchange and crystalline transform.Interatomic forces between Cs-O atoms split the pore channels of the pristine In-aip,endowing In-aip(Cs)with multidimensional charge transport channels,In addition,the partially freed Cs~+in the interlayer compensates for the vacancy of A-site cations during the perovskite preparation process.The In-aip(Cs)modified perovskite films have a flat morphology,large grains and excellent optoelectronic properties.Benefiting from the high-quality perovskite films and faster charge extraction,the In-aip(Cs)-modified PSCs achieved a champion PCE of 23.03%,superior to the In-aip-modified(22.29%)and control device(21.13%),More importantly,the unencapsulated PSCs modified with In-aip(Cs)exhibited outstanding humidity and thermal stability.Over a period of almost 1000 h,the unencapsulated In-aip(Cs)-modified device retained 85%of its initial PCE after storing in a glove box at 85℃,and retained 87%of the primary PCE upon storage in ambient condition at 25℃under a humidity of 40%.

Manipulating Crystal Growth and Secondary Phase PbI_(2)to Enable Efficient and Stable Perovskite Solar Cells with Natural Additives

In perovskite solar cells(PSCs),the inherent defects of perovskite film and the random distribution of excess lead iodide(PbI_(2))prevent the improvement of efficiency and stability.Herein,natural cellulose is used as the raw material to design a series of cellulose derivatives for perovskite crystallization engineering.The cationic cellulose derivative C-Im-CN with cyano-imidazolium(Im-CN)cation and chloride anion prominently promotes the crystallization process,grain growth,and directional orientation of perovskite.Meanwhile,excess PbI_(2)is transferred to the surface of perovskite grains or formed plate-like crystallites in local domains.These effects result in suppressing defect formation,decreasing grain boundaries,enhancing carrier extraction,inhibiting non-radiative recombination,and dramatically prolonging carrier lifetimes.Thus,the PSCs exhibit a high power conversion efficiency of 24.71%.Moreover,C-Im-CN has multiple interaction sites and polymer skeleton,so the unencapsulated PSCs maintain above 91.3%of their initial efficiencies after 3000 h of continuous operation in a conventional air atmosphere and have good stability under high humidity conditions.The utilization of biopolymers with excellent structure-designability to manage the perovskite opens a state-of-the-art avenue for manufacturing and improving PSCs.

Interfacial modification using the cross-linkable tannic acid for highly-efficient perovskite solar cells with excellent stability

Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being commercial.PSC device instability can be caused by a variety of reasons,including ions diffusion,surface and grain boundary defects,etc.In this work,the cross-linkable tannic acid(TA)is introduced to modify perovskite film through post-treatment method.The numerous organic functional groups(–OH and C=O)in TA can interact with the uncoordinated Pb^(2+)and I^(-)ions in perovskite,thus passivating defects and inhibiting ions diffusion.In addition,the formed TA network can absorb a small amount of the residual moisture inside the device to protect the perovskite layer.Furthermore,TA modification regulates the energy level of perovskite,and reduces interfacial charge recombination.Ultimately,following TA treatment,the device efficiency is increased significantly from 21.31%to 23.11%,with a decreased hysteresis effect.Notably,the treated device shows excellent air,thermal,and operational stability.In light of this,the readily available,inexpensive TA has the potential to operate as a multipurpose interfacial modifier to increase device efficiency while also enhancing device stability.

Multifunctional interfacial molecular bridge enabled by an aggregation-induced emission strategy for enhancing efficiency and UV stability of perovskite solar cells

The interface defects between the electron transport layer(ETL)and the perovskite layer,as well as the low ultraviolet(UV)light utilization rate of the perovskite absorption layer,pose significant challenges for the commercialization of perovskite solar cells(PSCs).To address this issue,this paper proposes an innovative multifunctional interface modulation strategy by introducing aggregation-induced emission(AIE)molecule 5-[4-[1,2,2-tri[4-(3,5-dicarboxyphenyl)phenyl]ethylene]phenyl]benzene-1,3-dicarboxylic acid(H_(8)ETTB)at the SnO_(2)ETL/perovskite interface.Firstly,the interaction of H_(8)ETTB with the SnO_(2)surface,facilitated by its carboxyl groups,is effective in passivating surface defects caused by noncoord inated Sn and O vacancies.This interaction enhances the conductivity of the SnO_(2)film and adjusts energy levels,leading to enhanced charge carrier transport.Simultaneously,H_(8)ETTB can passivate noncoord inated Pb^(2+)ions at the perovskite interface,promoting perovskite crystallization and reducing the interface energy barrier,resulting in a perovskite film with low defects and high crystalline quality.More importantly,the H_(8)ETTB molecule,can convert UV light into light absorbable by the perovskite,thereby reducing damage caused by UV light and improving the device's utilization of UV.Consequently,the champion PSC based on SnO_(2)-H_(8)ETTB achieves an impressing efficiency of 23.32%and significantly improved photostability compared with the control device after continuous exposure to intense UV radiation.In addition,the Cs_(0.05)(FA_(0.95)MA_(0.05))_(0.95)Pb(I_(0.95)Br_(0.05))_(3)based device can achieve maximum efficiency of 24.01%,demonstrating the effectiveness and universality of this strategy.Overall,this innovative interface bridging strategy effectively tackles interface defects and low UV light utilization in PSCs,presenting a promising approach for achieving highly efficient and stable PSCs.

Modulation on electrostatic potential to build a firm bridge at NiO_(x)/perovskite interface for efficient and stable perovskite solar cells

The NiO_(x)/perovskite interface in NiO_(x)-based inverted perovskite solar cells(PSCs)is one of the main issues that restrict device performance and long-term stability,as the unwanted interfacial defects and undesirable redox reactions cause severe interfacial non-radiative recombination and open-circuit voltage(Voc)loss.Herein,a series of self-assembled molecules(SAMs)are employed to bind,bridge,and stabilize the NiO_(x)/perovskite interface by regulating the electrostatic potential.Based on systematically theoretical and experimental studies,4-pyrazolecarboxylic acid(4-PCA)is proven as an efficient molecule to simultaneously passivate the NiO_(x)and perovskite surface traps,release the interfacial tensile stress as well as quench the detrimental interface redox reactions,thus effectively suppressing the interfacial non-radiative recombination and enhancing the quality of perovskite crystals.Consequently,the PSCs with 4-PCA treatment exhibited an eminently increased Voc,leading to a significant increase in power conversion efficiency from 21.28%to 23.77%.Furthermore,the unencapsulated devices maintain 92.6%and 81.3%of their initial PCEs after storing in air with a relative humidity of 20%–30%for 1000 h and heating at 65℃for 500 h in a N_(2)-filled glovebox,respectively.