Enhancing performance of low-temperature processed CsPbI2Br all-inorganic perovskite solar cells using polyethylene oxide-modified TiO_(2)

CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state density and serious charge recombination between low-temperature processed TiO_(2)film and inorganic perovskite layer interface seriously restrict the performance of all-inorganic PSCs.Here a thin polyethylene oxide(PEO)layer is employed to modify TiO_(2)film to passivate traps and promote carrier collection.The impacts of PEO layer on microstructure and photoelectric characteristics of TiO_(2)film and related devices are systematically studied.Characterization results suggest that PEO modification can reduce the surface roughness of TiO_(2)film,decrease its average surface potential,and passivate trap states.At optimal conditions,the champion efficiency of CsPbI_(2)Br PSCs with PEO-modified TiO_(2)(PEO-PSCs)has been improved to 11.24%from 9.03%of reference PSCs.Moreover,the hysteresis behavior and charge recombination have been suppressed in PEO-PSCs.

Efficient and stable planar all-inorganic perovskite solar cells based on high-quality CsPbBr3 films with controllable morphology

All-inorganic cesium lead bromide(CsPbBr3)perovskite is attracting growing interest as functional materials in photovoltaics and other optoelectronic devices due to its superb stability.However,the fabrication of high-quality CsPbBr3 films still remains a big challenge by solution-process because of the low solubility of the cesium precursor in common solvents.Herein,we report a facile solution-processed approach to prepare high-quality CsPbBr3 perovskite films via a two-step spin-coating method,in which the Cs Br methanol/H2 O mixed solvent solution is spin-coated onto the lead bromide films,followed by an isopropanol-assisted post-treatment to regulate the crystallization process and to control the film morphology.In this fashion,dense and uniform CsPbBr3 films are obtained consisting of large crystalline domains with sizes up to microns and low defect density.The effectiveness of the resulting CsPbBr3 films is further examined in perovskite solar cells(PSCs)with a simplified planar architecture of fluorine–doped tin oxide/compact Ti O2/CsPbBr3/carbon,which deliver a maximum power conversion efficiency of 8.11%together with excellent thermal and humidity stability.The present work offers a simple and effective strategy in fabrication of high-quality CsPbBr3 films for efficient and stable PSCs as well as other optoelectronic devices.

Tri-functionalized TiOxCl4-2x accessory layer to boost efficiency of hole-free, all-inorganic perovskite solar cells

Tin dioxide(SnO2) is generally regarded as a promising electron-transporting layer(ETL) for state-of-theart perovskite solar cells(PSCs), however, the ubiquitous oxygen-vacancy-related defects at SnO2 surface and the large energy difference between conduction band of SnO2 and perovskite layer undoubtedly cause severe charge carrier recombination, resulting in sluggish charge extraction efficiency and non-negligible open-circuit voltage(Voc) loss. Herein, a chlorine-containing TiOxCl4-2x accessory layer is fabricated by immersing SnO2 layer into the TiCl4 aqueous solution to passivate the surface oxygen-vacancy-related defects of SnO2 layer and to set an intermediate energy level at ETL/perovskite interface in all-inorganic cesium lead tri-bromine(CsPbBr3) PSCs. Furthermore, the TiOxCl4-2x layer also improves the infiltration of SnO2 layer surface toward perovskite precursor for high-quality perovskite film. Finally, the hole-free, allinorganic CsPbBr3PSC with a structure of FTO/SnO2/TiOxCl4-2x/Cs0.91Rb0.09PbBr3/carbon achieves a champion efficiency of 10.44% with a Vocas high as 1.629 V in comparison to 8.31% for control device. Moreover, the optimized solar cell presents good stability in 80% humidity in air.

Organic additives in all-inorganic perovskite solar cells and modules:from moisture endurance to enhanced efficiency and operational stability

Power conversion efficiency(PCE) of perovskite solar cells(PSC) has been skyrocketed to certified 25.5% owing to their improved and tunable optoelectronic properties. Although, various strategies have been adopted to date regarding PCE and stability enhancement within PSC technology, certain instability factors(moisture, heat, light) are hindering their commercial placement. Recently, all-inorganic PSCs got hype in the photovoltaic research community after they attained PCE > 20% and due to their significant endurance against heat and light mishmashes, but there only left moisture sensitivity as the only roadblock for their industrial integration. Here, we review the recent progress of additive inclusion into allinorganic(CsPbX_(3)) PSCs to stabilize their intrinsic structure and to withstand the performance limiting factors. We start with the detailed description of chemical instability of different perovskite compositions, phase segregation, and how organic molecules and dyes help to repair the structural defects to improve the overall PCE and stability of PSCs. Moisture endurance as a result of chemical passivation through organic additives, low-dimensional inorganic PSCs to enhance device stability and scalable fabrication of CsPbX_(3) PSCs are also reviewed. The challenges of module degradation and design implications with proposed strategies and outlook are interpreted in the ending phrases of this review.

Cross-layer all-interface defect passivation with pre-buried additive toward efficient all-inorganic perovskite solar cells

The buried interface in the perovskite solar cell(PSC)has been regarded as a breakthrough to boost the power conversion efficiency and stability.However,a comprehensive manipulation of the buried interface in terms of the transport layer,buried interlayer,and perovskite layer has been largely overlooked.Herein,we propose the use of a volatile heterocyclic compound called 2-thiopheneacetic acid(TPA)as a pre-buried additive in the buried interface to achieve cross-layer all-interface defect passivation through an in situ bottom-up infiltration diffusion strategy.TPA not only suppresses the serious interfacial nonradiative recombination losses by precisely healing the interfacial and underlying defects but also effectively enhances the quality of perovskite film and releases the residual strain of perovskite film.Owing to this versatility,TPA-tailored CsPbBr3 PSCs deliver a record efficiency of 11.23% with enhanced long-term stability.This breakthrough in manipulating the buried interface using TPA opens new avenues for further improving the performance and reliability of PSC.

Antimony doped CsPbI_(2)Br for high-stability all-inorganic perovskite solar cells

All-inorganic perovskites,adopting cesium(Cs+)cation to completely replace the organic component of A-sites of hybrid organic–inorganic halide perovskites,have attracted much attention owing to the excellent thermal stability.However,all-inorganic iodine-based perovskites generally exhibit poor phase stability in ambient conditions.Herein,we propose an efficient strategy to introduce antimony(Sb^(3+))into the crystalline lattices of CsPbI_(2)Br perovskite,which can effectively regulate the growth of perovskite crystals to obtain a more stable perovskite phase.Due to the much smaller ionic radius and lower electronegativity of trivalent Sb^(3+)than those of Pb^(2+),the Sb^(3+)doping can decrease surface defects and suppress charge recombination,resulting in longer carrier lifetime and negligible hysteresis.As a result,the all-inorganic perovskite solar cells(PSCs)based on 0.25%Sb^(3+)doped CsPbI_(2)Br light absorber and screen-printable nanocarbon counter electrode achieved a power conversion efficiency of 11.06%,which is 16%higher than that of the control devices without Sb^(3+)doping.Moreover,the Sb^(3+)doped all-inorganic PSCs also exhibited greatly improved endurance against heat and moisture.Due to the use of low-cost and easy-to-process nanocarbon counter electrodes,the manufacturing process of the all-inorganic PSCs is very convenient and highly repeatable,and the manufacturing cost can be greatly reduced.This work offers a promising approach to constructing high-stability all-inorganic PSCs by introducing appropriate lattice doping.

Precursor engineering enables high-performance all-inorganic CsPbIBr_(2) perovskite solar cells with a record efficiency approaching 13%

All-inorganic CsPbIBr_(2) perovskite has attracted widespread attention in photovoltaic and other optoelectronic devices because of its superior thermal stability.However,the deposition of high-quality solutionprocessed CsPbIBr_(2) perovskite films with large thicknesses remains challenging.Here,we develop a triple-component precursor(TCP) by employing lead bromide,lead iodide,and cesium bromide,to replace the most commonly used double-component precursor(DCP) consisting of lead bromide and cesium iodide.Remarkably,the TCP system significantly increases the solution concentration to 1.3 M,leading to a larger film thickness(~390 nm) and enhanced light absorption.The resultant CsPbIBr_(2) films were evaluated in planar n-i-p structured solar cells,which exhibit a considerably higher optimal photocurrent density of 11.50 mA cm^(-2) in comparison to that of DCP-based devices(10.69 mA cm^(-2)).By adopting an organic surface passivator,the maximum device efficiency using TCP is further boosted to a record efficiency of 12.8% for CsPbIBr_(2) perovskite solar cells.

Interface engineering of high performance all-inorganic perovskite solar cells via low-temperature processed TiO2 nanopillar arrays

All-inorganic perovskite solar cells suffer from low performance due to unsatisfactory carrier transport and light harvesting efficiency.Semiconductor nanopillar arrays can reduce light reflection loss and suppress exciton recombination dynamics in optoelectronic devices.In all-inorganic perovskite solar cells,few studies employing TiO_(2)nanopillar arrays(TiO_(2)NaPAs)have been reported to improve the device performance.Herein,well-arranged TiO_(2)NaPAs are chosen to enhance the interfacial contact between perovskite and electron transporting layers for improving the carrier transport.Notably,TiO_(2)NaPAs can be directly fabricated on rigid/flexible substrates at roughly room temperature by unique glancing angle deposition,which is more available than high-temperature hydrothermal/solvothermal methods.By embedding TiO_(2)NaPAs into chemical processable CsPbI2Br layers,continuous and intimate films are readily formed,guaranteeing large physical contact for facilitating more effective electron injection and charge separation.The vertically grown TiO_(2)NaPAs also provide a straightforward electron transporting path to electrodes.In addition,TiO_(2)NaPAs can guide the incident light and enhance the light-harvesting ability of CsPbI2Br films.As a result,the solar cell with TiO_(2)NaPAs displays a power conversion efficiency of 11.35%higher than planar control of 10.04%,and exhibits better long-term thermal stability.This strategy provides an opportunity by constructing direct interfacial regulation towards the performance improvement of inorganic perovskite solar cells.

Surface passivation and hole extraction:Bifunctional interfacial engineering toward high-performance all-inorganic CsPbIBr2 perovskite solar cells with efficiency exceeding 12%

All-inorganic CsPbIBr2perovskite solar cells(PSCs)have attracted considerable research attention in recent years due to their excellent thermal stability.However,their power conversion efficiencies(PCEs)are relatively low and still far below the theoretical limit.Here,we report the use of an organic dye molecule(namely VG1-C8)as a bifunctional interlayer between perovskite and the hole-transport layer in CsPbIBr2PSCs.Combined experimental and theoretical calculation results disclose that the multiple Lewis base sites in VG1-C8 can effectively passivate the trap states on the perovskite films.Meanwhile,theπ-conjugated dye molecule significantly accelerates the hole extraction from the perovskite absorber as evidenced by the photoluminescence analysis.Consequently,the VG1-C8 treatment simultaneously boosts the photovoltage and photocurrent density values from 1.26 V and 10.80 mA cm^(-2) to 1.31 V and 12.44 m A cm^(-2),respectively.This leads to a significant enhancement of PCE from 9.20%to12.10%under one sun irradiation(AM 1.5G).To our knowledge,this is the record efficiency reported so far for CsPbIBr_(2) PSCs.Thus,the present work demonstrates an effective interfacial passivation strategy for the development of highly efficient PSCs.

Slow halide exchange in CsPbIBr_(2) films for high-efficiency,carbon-based,all-inorganic perovskite solar cells

Halide exchange offers a versatile way to modify the properties of halide perovskites,but it is particularly challenging to slow the reaction rate to restrain defect growth in the products.Herein,we propose a slow halide exchange strategy to simultaneously fine-tune the optical and microstructural characteristics of CsPbIBr_(2) films by physically pairing CsPbIBr_(2) and CH_(3)NH_(3)PbI_(3) films.Once a proper heating treatment is applied,halide exchange of Br^(-)and I^(-)ions between the films is activated,and the reaction rate can be well-controlled by the heating recipe,in which a high temperature can accelerate the exchange reaction,while a low temperature slows or stops it.By using an optimal halide exchange temperature(110℃)and time(2 h),the parent CsPbIBr_(2) film was transformed into high-quality CsPbI_(1+x)Br_(2-x) film,featuring an extended absorption onset from 590 to 625 nm,coarsened grains,improved crystallinity,reduced surface roughness,suppressed halide phase segregation,and identical stability to the pristine film.Accordingly,the efficiency of a carbon-based,all-inorganic perovskite solar cell(PSC)was boosted to 10.94%,which was much higher than that of the pristine CsPbIBr_(2) film(8.21%).The CsPbI_(1+x)Br_(2-x) PSC also possessed excellent tolerance against heat and moisture stresses.

Synchronous defect passivation of all-inorganic perovskite solar cells enabled by fullerene interlayer

All-inorganic CsPbI_(3-x)Br_(x)perovskite solar cells(PSCs)are advantageous in terms of high thermal stability,while its efficiency lags behind those of organic-inorganic hybrid perovskite counterparts.Defect passivations have been extensively applied for enhancing efficiency of all-inorganic PSCs,which are mainly based on univocal defect passivation of perovskite layer.Herein,we incorporated a bis-dimethylamino-functionalized fullerene derivative(abbreviated as PCBDMAM)as an interlayer between ZnO electron transport layer(ETL)and all-inorganic CsPbI_(2.25)Br_(0.75)perovskite layer,accomplishing synchronous defect passivations of both layers and consequently dramatic enhancements of efficiency and thermal stability of PSC devices.Upon spin-coating PCBDMAM onto ZnO ETL,the surface defects of ZnO especially oxygen vacancies can be effectively passivated due to the formation of Zn−N ionic bonds.In addition,PCBDMAM incorporation affords effective passivation of Pb_(I)and I_(Pb)antisite defects within the atop perovskite layer as well via coordination bonding with Pb^(2+).As a result,the regular-structure planar CsPbI_(2.25)Br_(0.75)PSC device delivers a champion power conversion efficiency(PCE)of 17.04%,which surpasses that of the control device(15.44%).Moreover,the PCBDMAM-incorporated PSC device maintains~80%of its initial PCE after 600 h heating at 85°C hot plate in N2 atmosphere,whereas PCE of the control device degrades rapidly to~62%after 460 h heating under identical conditions.Hence,PCBDMAM incorporation benefited dramatic improvement of the thermal stability of PSC device.

Inkjet-Printing Controlled Phase Evolution Boosts the Efficiency of Hole Transport Material Free and Carbon-Based CsPbBr_(3) Perovskite Solar Cells Exceeding 9%

Hole transport material free carbon-based all-inorganic CsPbBr_(3)perovskite solar cells(PSCs)are promising for commercialization due to its low-cost,high open-circuit voltage(V_(oc))and superior stability.Due to the different solubility of PbBr_(2)and CsBr in conventional solvents,CsPbBr_(3)films are mainly obtained by multi-step spin-coating through the phase evolution from PbBr_(2)to CsPb_(2)Br_(5)and then to CsPbBr_(3).The scalable fabrication of high-quality CsPbBr_(3)films has been rarely studied.Herein,an inkjet-printing method is developed to prepare high-quality CsPbBr_(3)films.The formation of long-range crystalline CsPb_(2)Br_(5)phase can effectively improve phase purity and promote regular crystal stacking of CsPbBr_(3).Consequently,the inkjet-printed CsPbBr_(3)C-PSCs realized PCEs up to 9.09%,8.59%and 7.81%with active areas of 0.09,0.25,and 1 cm^(2),respectively,demonstrating the upscaling potential of our fabrication method and devices.This high performance is mainly ascribed to the high purity,strong crystal orientation,reduced surface roughness and lower trap states density of the as-printed CsPbBr_(3)films.This work provides insights into the relationship between the phase evolution mechanisms and crystal growth dynamics of cesium lead bromide halide films.

Interfacial Voids Trigger Carbon-Based, All-Inorganic Cs Pb IBr2 Perovskite Solar Cells with Photovoltage Exceeding 1.33 V

A novel interface design is proposed for carbon-based,all-inorganic CsPbIBr2 perovskite solar cells(PSCs)by introducing interfacial voids between TiO2 electron transport layer and CsPbIBr2 absorber.Compared with the general interfacial engineering strategies,this design exempts any extra modification layer in final PSC.More importantly,the interfacial voids produced by thermal decomposition of 2-phenylethylammonium iodide trigger three beneficial e ects.First,they promote the light scattering in CsPbIBr2 film and thereby boost absorption ability of the resulting CsPbIBr2 PSCs.Second,they suppress recombination of charge carriers and thus reduce dark saturation current density(J0)of the PSCs.Third,interfacial voids enlarge built-in potential(Vbi)of the PSCs,awarding increased driving force for dissociating photo-generated charge carriers.Consequently,the PSC yields the optimized e ciency of 10.20%coupled with an open-circuit voltage(Voc)of 1.338 V.The Voc achieved herein represents the best value among CsPbIBr2 PSCs reported earlier.Meanwhile,the non-encapsulated PSCs exhibit an excellent stability against light,thermal,and humidity stresses,since it remains^97%or^94%of its initial e ciency after being heated at 85℃for 12 h or stored in ambient atmosphere with relative humidity of 30–40%for 60 days,respectively.

Nano Ag-enhanced photoelectric conversion efficiency in all-inorganic,hole-transporting-layer-free CsPbIBr_(2) perovskite solar cells

All-inorganic,hole-transporting-layer-free CsPbIBr_(2)perovskite solar cells have great potential for development,but their device performance needs to be further improved.Recently,metal nanostructures have been successfully applied in the field of solar cells to improve their performance.Nano Ag-enhanced power conversion efficiency(PCE)in one CsPbIBr_(2)perovskite solar cell utilizing localized surface plasmons of Ag nanoparticles(NPs)on the surface has been researched experimentally and by simulation in this paper.The localized surface plasmon resonance of Ag NPs has a near-field enhancement effect,which is expected to improve the light absorption of CsPbIBr_(2)perovskite photovoltaic devices.In addition,Ag NPs have a forward-scattering effect on the incident light,which can also improve the performance of CsPbIBr_(2)-based perovskite photovoltaic devices.By directly assembling Ag NPs(with a size of about 150 nm)on the surface of fluorine-doped tin oxide it is found when the particle surface coverage is 10%,the CsPbIBr_(2)perovskite photovoltaic device achieves a best PCE of 2.7%,which is 9.76%higher than that of the control group.Without changing any existing structure in the ready-made solar cell,this facile and efficient method has huge applications.To the best of our knowledge,this paper is the first report on nano Ag-enhanced photoelectric conversion efficiency in this kind of CsPbIBr_(2)perovskite solar cell.

Solar Cells Based on All-Inorganic Halide Perovskites:Progress and Prospects

The emergence of perovskite solar cells(PSCs)based on all-inorganic metal halide(IMH)has generated enormous interest in the photovoltaic research community,and the power conversion efficiency(PCE)has exceeded13%.Despite its outstanding performance in thermal stability,PSCs based on IMH still face problems such as the lack of a suitable band gap and the inability to generate large areas.In this review,we will summarize the latest progress of PSCs based on IMH.

High performance wide bandgap perovskite solar cell with low V_(OC) deficit less than 0.4 V

Wide bandgap perovskite solar cells(PSCs)have attracted significant attention because they can be applied to the top cells of tandem solar cells.However,high open-circuit voltage(V_(OC))deficit(>0.4 V)result from poor crystallization and high non-radiative recombination losses become a serious limitation in the pursuit of high performance.Here,the relevance between different Pbl_(2)proportions and performance parameters are revealed through analysis of surface morphology,residual stress,and photostability.The increase of Pbl_(2)proportion promotes crystal growth and reduces the work function of the perovskite film surface and promotes the energy level alignment with the carrier transport layer,which decreased the V_(OC)deficit.However,residual PbI_(2)exacerbated the stress level of perovskite film,and the resulting lattice disorder deteriorated the photostability of the device.Ultimately,after the synergistic passivation of residual PbI_(2)and PEAI,the V_(OC)achieves 1.266 V and V_(OC)deficit is less than 0.4 V,the record value in wide bandgap PSCs.

Reveal the large open-circuit voltage deficit of all-inorganic CsPbIBr_(2) perovskite solar cells

Due to excellent thermal stability and optoelectronic properties, all-inorganic perovskite is one of the promising candidates to solve the thermal decomposition problem of conventional organic–inorganic hybrid perovskite solar cells(PSCs),but the larger voltage loss(V_(loss)) cannot be ignored, especially CsPbIBr_(2), which limits the improvement of efficiency. To reduce V_(loss), one promising solution is the modification of the energy level alignment between the perovskite layer and adjacent charge transport layer(CTL), which can facilitate charge extraction and reduce carrier recombination rate at the perovskite/CTL interface. Therefore, the key issues of minimum V_(loss) and high efficiency of CsPbIBr_(2)-based PSCs were studied in terms of the perovskite layer thickness, the effects of band offset of the CTL/perovskite layer, the doping concentration of the CTL, and the electrode work function in this study based on device simulations. The open-circuit voltage(V_(oc)) is increased from 1.37 V to 1.52 V by replacing SnO_(2) with ZnO as the electron transport layer(ETL) due to more matching conduction band with the CsPbIBr;layer.

Enhanced charge extraction for all-inorganic perovskite solar cells by graphene oxide quantum dots modified TiO_(2)layer

All-inorganic cesium lead bromide(CsPbBr_(3))perovskite solar cells have been attracting growing interest due to superior performance stability and low cost.However,low light absorbance and large charge recombination at TiO_(2)/CsPbBr_(3)interface or within CsPbBr_(3)film still prevent further performance improvement.Herein,we report devices with high power conversion efficiency(9.16%)by introducing graphene oxide quantum dots(GOQDs)between TiO_(2)and perovskite layers.The recombination of interfacial radiation can be effectively restrained due to enhanced charge transfer capability.GOQDs with C-rich active sites can involve in crystallization and fill within the CsPbBr_(3)perovskite film as functional semiconductor additives.This work provides a promising strategy to optimize the crystallization process and boost charge extraction at the surface/interface optoelectronic properties of perovskites for high efficient and low-cost solar cells.

Significant performance enhancement of all-inorganic CsPbBr_(3)perovskite solar cells enabled by Nb-doped SnO_(2)as effective electron transport layer

All-inorganic CsPbBr_(3)-based perovskite solar cells(PSCs)have attracted great attention because of their high chemical and thermal stabilities in ambient air.However,the short-circuit current density(J_(sc))of CsPbBr_(3)-based PSCs is inadequate under solar illumination because of the wide bandgap,inefficient charge extraction and recombination loss,leading to lower power-conversion efficiencies(PCEs).It is envisaged that in addition to narrowing the bandgap by alloying,J_(sc)of the PSCs could be enhanced by effective improvement of electron transportation,suppression of charge recombination at the interface between the perovskite and electron transporting layer(ETL),and tuning of the space charge field in the device.In this work,Nb-doped SnO_(2)films as ETLs in the CsPbBr_(3)-based PSCs have been deposited at room temperature by high target utilization sputtering(Hi TUS).Through optimizing the Nb doping level alone,the J_(sc)was increased by nearly 19%,from 7.51 to 8.92 mA·cm^(-2)and the PCE was enhanced by 27%from 6.73%to 8.54%.The overall benefit by replacing the spin-coated SnO_(2)with sputtered SnO_(2)with Nb doping was up to 39%increase in J_(sc)and 62%increase in PCE.Moreover,the PCE of the optimized device showed negligible degradation over exposure to ambient environment(T~25°C,RH~45%),with 95.4%of the original PCE being maintained after storing the device for 1200 h.

Non-destructive buffer enabling near-infrared-transparent inverted inorganic perovskite solar cells toward 1400 h light-soaking stable perovskite/Cu(In,Ga)Se_(2) tandem solar cells

Near-infrared(NIR)transparent inverted all-inorganic perovskite solar cells(PSCs)are excellent top cell candidates in tandem applications.An essential challenge is the replacement of metal contacts with transparent conductive oxide(TCO)electrodes,which requires the introduction of a buffer layer to prevent sputtering damage.In this study,we show that the conventional buffers(i.e.,small organic molecules and atomic layer deposited metal oxides)used for organic-inorganic hybrid perovskites are not applicable to all-inorganic perovskites,due to non-uniform coverage of the vulnerable layers underneath,deterioration upon ion bombardment and moisture induced perovskite phase transition,A thin film of metal oxide nanoparticles by the spin-coating method serves as a non-destructive buffer layer for inorganic PSCs.All-inorganic inverted near-infrared-transparent PSCs deliver a PCE of 17.46%and an average transmittance of 73.7%between 780 and 1200 nm.In combination with an 18.56%Cu(In,Ga)Se_(2) bottom cell,we further demonstrate the first all-inorganic perovskite/CIGS 4-T tandem solar cell with a PCE of 24.75%,which exhibits excellent illumination stability by maintaining 86.7%of its initial efficiency after 1400 h.The non-destructive buffer lays the foundation for efficient and stable NIR-transparent inverted inorganic perovskite solar cells and perovskite-based tandems.