Perovskite Film Formation Research Articles

Gradient Thermal Annealing Assisted Perovskite Film Crystallization Regulation for Efficient and Stable Photovoltaic-Photodetection Bifunctional Device.

Perovskite crystallization regulation is essential to obtain excellent film optoelectronic properties and device performances. However, rapid crystallization during annealing always results in poor perovskite film and easy formation of trap, thereby greatly restricting device performance due to severe non-radiative recombination. Here, an easy and reproducible gradient thermal annealing (GTA) approach is used to regulate the perovskite crystallization. Through a low-temperature initial annealing of GTA, the solvent evaporation is slowed down, thus extending nucleation time and providing a buffer for the rapid crystallization of perovskite grains in the subsequent high-temperature stage. As a result, completely converted and highly crystalline perovskite is obtained with 1.6 times larger grain size, reduced trap density and suppressed non-radiative recombination of photo-generated carriers. The film crystallinity is also enhanced with more advantageous (100) and (111) lattice facets which are favorable for carrier transport. Consequently, the perovskite photodetectors exhibit a large linear dynamic range of 174dB and an excellent response even under ultra-weak light of 303 pW. Meanwhile, perovskite solar cells achieved increased PCE and maintained 85% of original efficiency after heating at 65°C for nearly 1000 h under unencapsulated conditions. To the knowledge, this represents the best performance reported for a perovskite photovoltaic-photodetection bifunctional device.

Cost-Effective Acetonitrile-Based Precursor Solution Mitigates Heterogeneous Nucleation for Efficient and Stable Perovskite Solar Cells.

Solution-processing is the primary method for fabricating high-efficiency perovskite solar cells (PSCs), where solvent choice critically influences film formation and quality. Although additives can optimize film formation dynamics by balancing nucleation and growth of perovskite, they can also induce heterogeneous nucleation due to competitive coordination and varying crystallization kinetics, leading to compositional heterogeneity and structural disorders. Herein, a perovskite precursor solution is developed using acetonitrile (ACN) as a weak coordination host solvent instead of the traditional N,N-dimethylformamide (DMF). The ACN-based perovskite precursor solution reduces heterogeneous nucleation typically caused by the competitive coordination effect of DMF, and cuts costs by half compared to DMF-based precursor solutions. This approach promotes a single crystallization pathway via a dimethyl sulfoxide-solvated intermediate phase to α-FAPbI3, which extends the anti-solvent operation window, and enhances the crystallinity of perovskite films, and reduces defect states. The power conversion efficiencies (PCE) of 23.62% and 20.13% is achieved for the PSC and minimodule, respectively. The PSC retains over 97% of its initial efficiency after 800h of continuous illumination under maximum power point tracking (MPPT). These findings provide valuable insights into solvent interactions in perovskite film formation and offer a cost-effective strategy for improving the device's performance and stability.

Studying the effect of ambient temperature variations on perovskite precursor film formation using different antisolvents

This study investigates the sensitivity of two antisolvents to ambient temperature fluctuations during the fabrication of triple-cation perovskite thin films. Chlorobenzene (CB) and ethyl acetate (EA) were employed as antisolvents in the preparation of perovskite solar cells (PSCs) under identical ambient temperature variation conditions. The experimental results reveal that the quality of the perovskite films does not exhibit a consistent trend in response to ambient temperature changes depending on the antisolvent used. When CB was used as the antisolvent, the highest-performing device, produced at an ambient temperature of 18 °C, achieved a power conversion efficiency (PCE) of 19.9 %. In contrast, when EA was employed as the antisolvent, the highest-performing device was fabricated at 25 °C, reaching a PCE of 20.5 %. Furthermore, when the ambient temperature exceeded 30 °C, all films prepared with either antisolvent exhibited significant cracking, indicating that elevated temperatures adversely affect perovskite film formation. To further investigate the mechanism through which ambient temperature affects the film-forming process, antisolvents at varying temperatures were used during perovskite film preparation to simulate transient temperature increases during formation. This study reveals that the impact of ambient temperature variations on perovskite film formation does not exhibit a uniform trend but is significantly influenced by the choice of antisolvent. Moreover, this work offers valuable insights for optimizing the fabrication of high-quality perovskite thin films.

Synchrotron Radiation-Based In Situ GIWAXS for Metal Halide Perovskite Solution Spin-Coating Fabrication.

Solution-processable perovskite-based devices are potentially very interesting because of their relatively cheap fabrication cost but outstanding optoelectronic performance. However, the solution spin-coating process involves complicated processes, including perovskite solution droplets, nucleation of perovskite, and formation of intermediate perovskite films, resulting in complicated crystallization pathways for perovskite films under annealing. Understanding and therefore controlling the fabrication process of perovskites is difficult. Recently, synchrotron radiation-based in situ grazing-incidence wide-angle X-ray scattering (GIWAXS) techniques, which possess the advantages of high collimation, high resolution, and high brightness, have enabled to bridge complicated perovskite structure information with device performance by revealing the real-time crystallization pathways of perovskites during the spin-coating process. Herein, the developments of synchrotron radiation-based in situ GIWAXS are discussed in the study of the crystallization process of perovskites, especially revealing the important crystallization mechanisms of state-of-the-art perovskite optoelectronic devices with high performance. At the end, several potential applications and challenges associated with in situ GIWAXS techniques for perovskite-based devices are highlighted.

MXene-Embedded PEDOT:PSS Hole-Transport Material for Lead-Free Perovskite Solar Cells.

Improving the energy alignment between charge-transport layers and the perovskite is crucial for further enhancing the photovoltaic performance of tin-based perovskite solar cells (PSCs). Herein, the role of Ti3C2T x MXene in a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transport layer (HTL) on the photovoltaic properties of PSCs is investigated as a function of its concentration. An improved perovskite film formation with reduced pinhole density and a more uniform contact potential difference is noted when MXene is embedded in the PEDOT:PSS HTL. The work function of the HTL is increased according to photoelectronic measurements, leading to a favorable energy alignment with the HOMO of PEA0.2FA0.8SnI3 perovskite. PSCs fabricated using a MXene-embedded PEDOT:PSS HTL delivered a power conversion efficiency (PCE) of 8.35% compared to 7.35% from the pristine counterpart, while retaining ∼90% of its initial PCE after 450 h of storage in a N2 atmosphere.

F for Fantastic: Fostering Stability and Efficiency in Perovskite Solar Cells via Comb-Like Perfluoroalkyl-g-Polyethylenimine Additive.

Additive engineering has emerged as a promising strategy to address the inherent instability challenges of perovskite solar cells (PSCs) in the pursuit of commercial viability. However, achieving multifunctionality using a singular additive remains a considerable challenge. In this study, a novel comb-like multifunctional perfluoroalkyl-g-polyethylenimmonium iodide (FPEI·HI) as additives to the PbI2 precursor solution to facilitate the formation of high-quality and water-resistant perovskite films is presented. FPEI·HI establishes robust interactions with both formamidinium iodide (FAI) and PbI2, mediated by hydrogen bonding and Lewis acid-base interactions. These interactions play a pivotal role in simultaneously passivating negative and positive charged defects within the perovskite structure. Furthermore, the inclusion of perfluoroalkyl chains serves as resilience against moisture intrusion. As a consequence of these effects, a notably high device efficiency of 24.29% is achieved, demonstrating comprehensive improvement in various photovoltaic parameters compared to the control device (22.51%). Notably, unencapsulated devices exhibit remarkable stability in high-humidity environments, retaining 90% of their initial efficiency even after 2500h of storage. This work underscores the efficacy of FPEI·HI as a critical enabler for enhancing the stability and efficiency of perovskite solar cells, marking a significant stride toward their commercialization.

NiOx Passivation in Perovskite Solar Cells: From Surface Reactivity to Device Performance.

Nonstoichiometric nickel oxide (NiOx) is one of the very few metal oxides successfully used as hole extraction layer in p-i-n type perovskite solar cells (PSCs). Its favorable optoelectronic properties and facile large-scale preparation methods are potentially relevant for future commercialization of PSCs, though currently low operational stability of PSCs is reported when a NiOx hole extraction layer is used in direct contact with the perovskite absorber. Poorly understood degradation reactions at this interface are seen as cause for the inferior stability, and a variety of interface passivation approaches have been shown to be effective in improving the overall solar cell performance. To gain a better understanding of the processes happening at this interface, we systematically passivated specific defects on NiOx with three different categories of organic/inorganic compounds. The effects on NiOx and the perovskite (MAPbI3) deposited on top were investigated using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Here, we find that the perovskite's structural stability and film formation can be significantly affected by the passivation treatment of the NiOx surface. In combination with density functional theory (DFT) calculations, a likely origin of NiOx-perovskite degradation interactions is proposed. The surface passivated NiOx layers were incorporated into MAPbI3-based PSCs, and the influence on device performance and operational stability was investigated by current-voltage (J-V) characterization, impedance spectroscopy (IS), and open circuit voltage decay (OCVD) measurements. Interestingly, we find that a superior structural stability due to interface passivation must not relate to high operational stability. The discrepancy comes from the formation of excess ions at the interface, which negatively impacts all solar cell parameters.

Controlled solid‐state Phase Transition of Formamidinium Dominated Perovskite Layers Fabricated Through Magnetron Sputtering for Photovoltaics

AbstractPerovskite solar cells (PSCs) based on formamidinium lead iodide (FAPbI3) have demonstrated the highest power conversion efficiencies. Typically fabricated through solution‐processing, FAPbI3 films necessitate intricate crystallization control to avoid the formation of a more stable non‐perovskite phase. Magnetron sputtering, an effective solvent‐free technique, has gained attention for producing large‐area perovskite films. Here, a novel approach to create high‐quality FAPbI3‐based perovskite thin films by employing magnetron sputtering is presented. Specifically, a mechanosynthesized blend of (FA1‐xMAx)Pb(I1‐xBrx)3 (MA = methylammonium) is used as a single‐source target for sputtering, and a post‐annealing transforms various phases in the initial deposited film into coherent FAPbI3‐based films with an ultra‐long and controlled crystallization process. Despite minimal residual MABr after post‐annealing, its presence is crucial in the formation of perovskite film, as evidenced by a distinct solid‐state phase transformation process is presented. A comprehensive investigation of the films' structural, compositional, and optical properties, with respect to varying MABr doping ratios, reveals details of perovskite phase development and the pivotal influence of MABr. PSCs fabricated with the optimized films display a substantial increase in the power conversion efficiency, reaching 20.1%. These results underscore the potential of combining magnetron sputtering and post‐annealing in the scalable production of high‐efficiency PSCs.

All-solution preparation of perovskite light-emitting diodes in ambient air through film-forming regulation of light-emitting layers based on dual-additive doping and oxygen plasma treatment

Organic-inorganic hybrid perovskites are promising for optoelectronics owing to their high color purity, tunable bandgaps, and low nonradiative recombination rates. However, challenges such as rough surfaces and poor film-forming properties constrain the optoelectronic performance of light-emitting devices. Herein, the PEDOT:PSS film treated by oxygen plasma serves as the hole transport layer, while the formation of perovskite films is optimized by dual-additive doping of PEO and TPBi in ambient air. The results show that the PEDOT:PSS films with PSSH-rich after oxygen plasma treatment provide more nucleation sites, favoring the formation of the perovskite film. Meanwhile, the dual-additive prompts to form a dense and uniform film as well. The intrinsic mechanisms involve PEO as a binder to fill grain gaps and improve water-oxygen stability in the perovskite film, while TPBi acts as a passivator to stimulate uniform nucleation and dense crystallization, improving the grain coverage of the light-emitting layer. Under atmospheric conditions, all-solution processed perovskite devices reach a maximum luminance of 810.4 cd m−2 and a maximum current efficiency of 0.437 cd A−1. This work highlights the significance of using oxygen plasma treatment and additives to improve the performance of perovskite films and achieve superior PeLEDs.

Stabilizing Solution–Substrate Interaction of Perovskite Ink on PEDOT:PSS for Scalable Blade Coated Narrow Bandgap Perovskite Solar Modules by Gas Quenching

The development of scalable 1.25 eV mixed Pb–Sn perovskite solar modules by blade coating lags behind Pb‐based perovskites due to limited understanding of solution–substrate interaction of the perovskite ink on PEDOT:PSS and subsequent gas quenching. To address this challenge, the wet film deposition and quenching process to better understand narrow bandgap perovskite film formation on PEDOT:PSS are studied. It is found that the wetting of Pb–Sn perovskite ink on PEDOT:PSS is highly unstable over relevant coating time scales, causing the contact angles to decrease rapidly from 42° to 16° within seconds. This instability leads to localized irregularities in the wet film, resulting in uneven solvent extraction and inhomogeneous nuclei density. As a result, rough perovskite films with voids at the buried interface are obtained. To overcome this problem, a quasistatic wetting process by reducing the blade coating speed is developed, thereby stabilizing the wetting behavior of Pb–Sn perovskite precursor ink on PEDOT:PSS. This optimized process facilitates the deposition of high‐quality, void‐free Pb–Sn perovskite films with uniform thickness over 8 cm of coating length using moderate (1.4 bar) N2 quenching. 20% efficient narrow bandgap perovskite solar cells and minimodules with 15.8% active area efficiency on 15.9 cm2 are achieved.

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 Pb2+ 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 (0D) Cs4PbBr6 phase and produce the two-dimensional (2D) CsPb2Br5 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 CsPbBr3 device, 14.86% for carbon-based CsPbI2Br device, 22.02% for FA0.97Cs0.03PbI3 device, respectively. Moreover, the unencapsulated CsPbBr3 PSC exhibits excellent stability under persistent exposure to humidity (80%) and heat (80 °C) for over 50 days.

Designed Additive to Regulated Crystallization for High Performance Perovskite Solar Cell

AbstractIt is a crucial role for enhancing the power conversion efficiency (PCE) of perovskite solar cells (PSCs) to prepare high‐quality perovskite films, which can be achieved by delaying the crystallization of perovskite film. Hence, we designed difluoroacetic anhydride (DFA) as an additive to regulating crystallization process thus reducing defect formation during perovskite film formation. It was found DFA reacts with DMSO by forming two molecules, difluoroacetate thioether ester (DTE) and difluoroacetic acid (DA). The strong bonding DTE⋅PbI2 and DA⋅PbI2 retard perovskite crystallization process for high‐quality film formation, which was monitored through in situ UV/Vis and PL tests. By using DFA additives, we prepared perovskite films with high‐quality and low defects. Finally, a champion PCE of 25.28 % was achieved with excellent environmental stability, which retained 95.75 % of the initial PCE after 1152 h at 25 °C under 25 % RH.

Designed Additive to Regulated Crystallization for High Performance Perovskite Solar Cell.

It is a crucial role for enhancing the power conversion efficiency (PCE) of perovskite solar cells (PSCs) to prepare high-quality perovskite films, which can be achieved by delaying the crystallization of perovskite film. Hence, we designed difluoroacetic anhydride (DFA) as an additive to regulating crystallization process thus reducing defect formation during perovskite film formation. It was found DFA reacts with DMSO by forming two molecules, difluoroacetate thioether ester (DTE) and difluoroacetic acid (DA). The strong bonding DTE⋅PbI2 and DA⋅PbI2 retard perovskite crystallization process for high-quality film formation, which was monitored through in situ UV/Vis and PL tests. By using DFA additives, we prepared perovskite films with high-quality and low defects. Finally, a champion PCE of 25.28 % was achieved with excellent environmental stability, which retained 95.75 % of the initial PCE after 1152 h at 25 °C under 25 % RH.

Formation and degradation mechanism of methylammonium lead iodide perovskite thin film fabricated by electrospray technique

Electrospray deposition technique has been reported previously for fabricating effective and stable perovskite thin film, leading to efficient perovskite solar cells. In this work, a comprehensive investigation of the formation mechanism of methylammonium lead iodide perovskite (CH3NH3PbI3) film by electrospray technique is demonstrated and compared to the formation mechanism through the conventional spin coating technique. In the electrospray process, charged MAI nanoparticles are gradually introduced onto the PbI2 film, intercalating within the PbI2 structure to produce the perovskite film. In contrast, the spin-coating method involves supplying the MAI solution in bulk, leading to perovskite crystal formation through the dissolution of the PbI2 layer by the MAI solution, followed by recrystallization into perovskite oriented in the [110] direction, 30° inclined to the substrate. The impact of charge and the electric field on the formation of perovskite film using the electrospray is explored.Furthermore, the intrinsic stability of perovskite films is monitored in real-time in a highly humid environment (≥80 % relative humidity (RH)) using in-situ Grazing Incidence Wide Angle X-ray Scattering (GIWAXS), and a degradation mechanism is proposed to enhance the durability of the perovskite-based devices. The study further delves into the comparison of the stability of electrosprayed and spin-coated perovskite film, and the impact of humidity level and the presence of a hole-transporting layer on the stability of the perovskite layer. Overall, this work provides a detailed understanding of the formation and humidity-induced degradation mechanism of electrosprayed perovskite films, offering insights that can extend to various applications of perovskite materials.

Phosphate-based ionic liquids for advanced interface modification in perovskite photovoltaics: Novel insights for ionic liquid molecule design

Interface modification stands out as a crucial method to enhance the performance of perovskite solar cells. This study explores the utilization of the ionic liquid 1-Methyl-3-propylimidazolium phosphate (MPIMPH), containing phosphate (PO43−) groups, as a modifier for SnO2/perovskite interfaces. Detailed investigations delve into the specific impact of IL MPIMPH on defects in tin dioxide, perovskite defects, perovskite crystallization, morphology, and overall device performance. Initially, Density Functional Theory (DFT) is employed to evaluate the defect passivation potential of different anions on tin vacancies within the SnO2 matrix, revealing the exceptional defect passivation ability of the PO43− group. Chemical interactions between ILs MPIMPH and SnO2, as well as perovskite, are confirmed, establishing a fundamental basis for interface defect passivation. ILs-based interface modification enhances interface contact, influencing the lead iodide conversion into perovskite and perovskite crystallization, ultimately leading to the formation of high-quality perovskite thin films. ILs also effectively suppress interfacial charge recombination and optimize the energy alignment of the SnO2/perovskite interface to enhance carrier extraction. Benefiting from the interface modification with ILs, the optimized device achieved an impressive device efficiency of 24.24 % with remarkable durability. This work provides an novel aspect for designing ionic liquids to enhance interface modification, contributing to upscaling and application of perovskite photovoltaics.

Development of Superior Nickel Oxide Layer for Boosted Hole‐Transport Performance in Perovskite Solar Cells

Although revolutionary power conversion efficiency progress has been realized for inverted perovskite solar cells (PSCs), the selection and optimization of the hole‐transporting materials (HTMs) are still crucial for fabricating high‐efficiency, stable, and low‐cost PSCs. Nickel oxide (NiOx) is widely used in the PSCs community for material design and modification. However, various NiOx synthesis processes lead to kinds of NiOx, and it is difficult to determine which NiOx is suitable for application in PSCs. Herein, two kinds of NiOx HTMs are synthesized using sol–gel processed and chemical‐calcination‐processed (CCP) routes for the preparation of PSCs. Based on the physical properties of two kinds of NiOx HTMs as well as the corresponding photovoltaic parameters of PSCs, it is demonstrated that superior NiOx HTMs is obtained by the CCP method with the following properties: high transmittance to ensure sufficient sunlight capture of perovskite, appropriate energy levels to promote hole extraction and transfer, high conductivity to support charge transfer, and a good wetting surface to boost perovskite spreading and film formation. Thus, in this study, the direction for the reasonable selection of HTMs is pointed out to prepare efficient PSCs.

Modulation of Nucleation and Growth Kinetics of Perovskite Nanocrystals Enables Efficient and Spectrally Stable Pure-Red Light-Emitting Diodes.

Perovskite light-emitting diodes (PeLEDs) based on CsPb(Br/I)3 nanocrystals (NCs) usually suffer from severe spectral instability under operating voltage due to the poor-quality PeNCs. Herein, zeolite was utilized to prepare high-quality CsPb(Br/I)3 NCs via promoting the homogeneous nucleation and growth and suppressing the Ostwald ripening of PeNCs. In addition, the decomposed zeolite interacted strongly with PeNCs through Pb-O bonds and hydrogen bonds, which inhibited the formation of defects and suppressed halide ion migration, leading to an improved photoluminescence quantum yield (PLQY) and enhanced stability of PeNCs. Moreover, the strong binding affinity of decomposed zeolite to PeNCs contributed to the formation of homogeneous perovskite films with high PLQY. As a result, pure-red PeLEDs with Commission International de I'Eclairage (CIE) coordinates of (0.705, 0.291) were fabricated, approaching the Rec. 2020 red primary color. The devices achieved a peak external quantum efficiency of 23.0% and outstanding spectral stability.

Influence of MACl on the Crystallization Kinetics of Perovskite via a Two-Step Method

The addition of methylammonium chloride (MACl) significantly improves the performance and stability of perovskite fabricated by two-step processes. However, its role in crystallization dynamics has not been thoroughly studied. In this work, a comparison study is carried out using different additions of MACl to investigate the impact of the perovskite crystallization dynamics. In situ grazing incidence wide-angle X-ray scattering (GIWAXS) observations during the annealing process of perovskite revealed that the amount of MACl significantly influences the crystallinity and orientation of the perovskite. Increasing the MACl addition enhances the crystallinity of the perovskite in the wet film‘s intermediate phase and strengthens the out-of-plane orientation of the FAPbI3 perovskite α-phase (001) planes during annealing. Moreover, it was found that both excessive and insufficient amounts of MACl introduce defects into the perovskite, which are detrimental to device performance. In contrast, an optimal ratio of MACl-9 mg leads to the formation of uniform and large-grained FAPbI3 perovskite films, with the longest carrier lifetimes (163.7 ns) compared to MACl-5 mg (68.4 ns) and MACl- 13 mg (120.1 ns). As a result, the fabricated MACl-9 mg-based solar cell achieved the highest efficiency (22.63%), which is higher than those of MACl-5 mg (21.47%) and MACl-13 mg (20.07%).

Enhancing performances of inverted perovskite solar cells by modifying the buried interface with sodium copper chlorophyllin

Defects at the buried interface and poor contact between the hole transport layer (HTL) poly-triarylamines (PTAA) and the perovskite layer are key issues affecting the efficiency and long-term stability of inverted perovskite solar cells (PSCs). In this study, we introduce sodium copper chlorophyllin (SCC, a chlorophyll derivative) as a modification agent at the HTL/perovskite interface to address these issues. Attributed to hydrophilic carboxylate groups of SCC, the wettability of the PTAA film is enhanced, facilitating the formation of the high-quality perovskite film. Meanwhile, SCC can interact with uncoordinated Pb2+ to passivate defects of the perovskite film at the buried interface. As a result, the power conversion efficiency (PCE) of inverted PSCs with the SCC modification reaches to 22.37% (from 20.58%) based on MAPbI3, and to 24.06% (from 21.54%) based on FAPbI3, respectively. Moreover, the devices show excellent stability in air and under light irradiation. This work indicates that the natural chlorophyll derivative is a promising candidate for improving the buried interface of high-performance inverted PSCs.

Bulk and interface passivation through potassium iodide additives engineering enables high-performance and humidity-stable CsPbBr3 perovskite solar cells

Organic-inorganic hybrid perovskite solar cells (PSCs) have gained significant attention in the past decade due to their exceptional photovoltaic performance and unique advantages. However, the organic cation component of the hybrid perovskites results in poor humidity resistibility and thermal stability. Replacing organic cations with inorganic cations, such as Cs+, to fabricate all-inorganic CsPbX3 PSCs, is an effective way to improve their stability. Among the CsPbX3 PSCs, full-brominated CsPbBr3 PSCs have excellent moisture and thermal tolerance, with great potential for commercialization. However, these PSCs suffer from energy loss during operation, and their photoelectric conversion efficiency is lower than that of mainstream hybrid PSCs. Additive engineering is an effective method to improve the quality of perovskite films, which introduces functional additives into the perovskite precursor to induce perovskite crystallization, achieve the passivation of uncoordinated ions defects, and finely tune the energy level structures. In this study, Potassium iodide (KI) was added to the CsBr precursor solution to participate in the formation of the CsPbBr3 perovskite thin film. The partial substitution of A-site cation in the ABX3 perovskite occurred during the film formation, leading to beneficial variation of the crystal structure and photoelectronic performance in the CsPbBr3 system. The planar-architecture device based on the modified CsPbBr3 layer could reach a best efficiency of 10.06 %, together with a high open-circuit voltage (Voc) of 1.60 V. The KI-doped CsPbBr3 based PSC can retain over 90 % of the original PCE even after 30 days of aging, thanks to the diminished defect density by the KI passivation.