Hole Transport Layer Material Research Articles

Pyrene‐Based Dopant‐Free Hole‐Transport Polymers with Fluorine‐Induced Favorable Molecular Stacking Enable Efficient Perovskite Solar Cells

AbstractA new class of polymeric hole‐transport materials (HTMs) are explored by inserting a two‐dimensionally conjugated fluoro‐substituted pyrene into thiophene and selenophene polymeric chains. The broad conjugated plane of pyrene and “Lewis soft” selenium atoms not only enhance the π–π stacking of HTM molecules greatly but also render a strong interaction with the perovskite surface, leading to an efficient charge transport/transfer in both the HTM layer and the perovskite/HTM interface. Note that fluorine substitution adjacent to pyrene boosts the stacking of HTMs towards a more favorable face‐on orientation, further facilitating the efficient charge transport. As a result, perovskite solar cells (PSCs) employing PE10 as dopant‐free HTM afford an excellent efficiency of 22.3 % and the dramatically enhanced device longevity, qualifying it among the best PSCs based on dopant‐free HTMs.

Pyrene-Based Dopant-Free Hole-Transport Polymers with Fluorine-Induced Favorable Molecular Stacking Enable Efficient Perovskite Solar Cells.

A new class of polymeric hole‐transport materials (HTMs) are explored by inserting a two‐dimensionally conjugated fluoro‐substituted pyrene into thiophene and selenophene polymeric chains. The broad conjugated plane of pyrene and “Lewis soft” selenium atoms not only enhance the π–π stacking of HTM molecules greatly but also render a strong interaction with the perovskite surface, leading to an efficient charge transport/transfer in both the HTM layer and the perovskite/HTM interface. Note that fluorine substitution adjacent to pyrene boosts the stacking of HTMs towards a more favorable face‐on orientation, further facilitating the efficient charge transport. As a result, perovskite solar cells (PSCs) employing PE10 as dopant‐free HTM afford an excellent efficiency of 22.3 % and the dramatically enhanced device longevity, qualifying it among the best PSCs based on dopant‐free HTMs.

Design and numerical investigations of eco-friendly, non-toxic (Au/CuSCN/CH3NH3SnI3/CdTe/ZnO/ITO) perovskite solar cell and module

A comprehensive study for design of higher energy conversion capacity of XSnI3 (X-CH3NH3) based perovskite solar cell has been carried out using solar cell capacitance simulator SCAPS-1D and the irradiation and temperature dependence of solar panel based on proposed ITO/ZnO/CdTe/CH3NH3SnI3/CuSCN/Au configuration has been explored by PVsyst photovoltaic software Package. The insight and suitability of ‘ZnO’ as electron transport layer material (ETLM), CH3NH3SnI3 as perovskite absorber, CuSCN as hole transport layer material (HTLM) and CdTe as active buffer layer has been elaborated for efficient device performance. The structural design of the composition for a unit area was optimized by variation in thickness of absorber layer, temperature and defect densities at interfaces. The response of the device in perspective of carrier generation and recombination, defects and defect densities was thoroughly explored. The energy conversion efficiency (ECE) presented in this work for optimized parameters is observed to be 21.24% with Voc = 0.8149 V, Jsc = 34.0535 mA/cm2 and FF = 76.57%. Investigations reveal that optimized thickness of perovskite absorber layer (∼4.72 µm) indicate the maximum extent for Jsc, FF and percentage efficiency due to creation of additional electron-hole pairs at standard applied conditions. The simulated electrical parameters obtained from SCAPS-1D were used as an input in PVsyst software package for solar module consisting of 60 cells and dimensions (2.2 × 1.1) m. The panel performance in context of output power, incident irradiation and temperature has been calculated and the simulation results for a specific geographical location are reported.

Influence of layer thickness, defect density, doping concentration, interface defects, work function, working temperature and reflecting coating on lead-free perovskite solar cell

Perovskite-based solar cells have made an impact in the photovoltaic industry by surpassing some of the established solar cell technologies, with power conversion efficiency (PCE) exceeding 23% already. Among them methylammonium lead tri iodide (MAPbI3) based perovskite solar cell (PSC) have been greatly focused upon. However, the toxic nature of lead (Pb) is a major area of concern in its wide spread applications. Nontoxic germanium (Ge) has emerged as an alternate to Pb in PSC due to its similar photovoltaic properties. In this work, numerical modelling of Ge based perovskite solar cell structure (FTO/TiO2/CH3NH3GeI3/Spiro-OMeTAD/Au) is performed using SCAPS software. A systematic approach is followed to investigate the effect of material thickness, doping concentration, work function, temperature, reflection and interface defect densities on the performance of PSC. Initially, all the cell parameters are optimized by keeping defect density constant. Once, the optimized structure is achieved the defect density is varied to investigate its effect on the cell performance. Finally, all the cell parameters are optimized at each defect density. Based on optimized simulation results, PCE of 17.74% is achieved with 15.77 mA/cm2 short-circuit current (JSC), 1.26 V open circuit voltage (VOC) and 88.64% fill factor (FF). Moreover, in the optimized cell structure Spiro-OMeTAD and gold (Au) are replaced with different copper (Cu) based hole transport layer (HTL) and anode materials respectively to study its effect on the cell performance. The best result is obtained with copper antimony sulfide (CuSbS2) and Copper Aluminate (CuAIO2) exhibiting PCE of 21.42% and 23.56% respectively.

Amorphous-conjugated polymer-additive approach to prepare quality Spiro-OMeTAD-based hole transporting material for efficient Sb2S3 solar cells

2,2′,7,7′-Tetrakis-(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene (Spiro-OMeTAD) is a common hole transport material (HTM) for efficient solar cells. However, the conventional Spiro-OMeTAD-based HTM contains the bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI) additive that often introduces pinholes into the HTM layer to deteriorate device performance. Here, we use amorphous polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) as an additive into the Spiro-OMeTAD-based HTM for efficient Sb2S3 solar cells. It is showed that MEH-PPV remarkably improves the quality of the HTM layer, suppresses the charge recombination and enhances the charge collection efficiency in the Sb2S3 solar cells. With the MEH-PPV additive, the power conversion efficiency of the solar cells is boosted up to 6.02% from the original 5.51% without the additive.

Linear cross-linkers enabling photothermally cured hole transport layer for high-performance quantum dots light-emitting diodes with ultralow efficiency roll-off

In quantum-dot light-emitting diodes (QLEDs), poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt(4,4′-(N-(4-butylphenyl))] (TFB) has been one of the most widely used hole-transport layer (HTL) materials. However, for solution-processed especially ink-jet printed QLEDs, TFB normally suffers from low glass-transition temperature and inter-layer erosions hindering to achieve both high device efficiency and stability. In the present work, three novel linear bis-benzophenone cross-linkers (BPO4, BPO6 and BPO8) were carefully designed and synthesized for constructing compact HTL with ∼ 100 % solvent resistance. Under a mild photothermal curing condition of 120 °C and 365 nm UV with a power of 16 mW cm−2, the introduction of these cross-linkers into TFB film, even at a low weight concentration of 3.33 %, not only resulted in the HTL with reduced free film volumes and hence compact three-dimensional networks in QLEDs, but also enhanced the hole transport ability, so that better charge balance in QDs layer and improved overall QLED performance could be achieved. In the BPO series which have varying alky lengths, the BPO6 with a medium central alkyl length showed the best thin film state, and thus enabled to improve the QLED device performance with the highest EQE of 16.77 % (20.22 lm W−1, 22.72 cd A-1), which is 20% higher than that of pristine TFB based device. From the peak EQE to the EQE at 20000 cd m−2, an ultra-low deviation of 1.73 % was observed in the TFB:BPO6 based red QLEDs. The T50 lifetime of TFB:BPO6 based QLEDs is almost twice of that of the pristine TFB based device. Our strategy demonstrates that developing linear cross-linkers for polymer HTL can facilitate forming compact and dense HTL, achieving simultaneous improvements in QLEDs device efficiency and stability.

High‐Performance Perovskite Solar Cells via Simulation Interactive Technology

CsPbBr3 film possesses high stability and easy manufacturing characteristics, rendering it attractive for applications in perovskite solar cells (PSCs). However, optical loss and energy level matching of different material layers are still the major factors, limiting the performance of PSCs. Herein, the finite element method (FEM) and density functional theory (DFT) calculations composed of simulation interaction technology are used to study the effects of different electron transport layer and hole transport layer materials on the optical performance of different PSC configurations. The effect of the charge transport layer (CTL) material and CsPbBr3 on the energy level matching and charge transport of the device is explained. The FEM simulation results show that inorganic CTL materials produce less parasitic absorption than the organic materials. The DFT calculation results give the microscopic design rules of the CTL material. In addition, PSCs with a light‐trapping structure are designed, which effectively suppressed surface reflection. Finally, through the screening of CTL materials and the design of advanced light‐trapping structures, the photocurrent of PSCs is increased by 69.8% (from 5.30 to 9.00 mA cm−2). This work provides a novel model for the screening of CTL materials for inorganic PSCs.

A New PEDOT Derivative for Efficient Organic Solar Cell with a Fill Factor of 0.80

AbstractAlthough PEDOT:PSS is the most prominently used conducting polymer as hole transporting layer (HTL) material in organic solar cells (OSCs), the strong acidity of PEDOT:PSS has been proved to cause corrosion on electrodes, which is largely responsible for device instability. At present, the development of a non‐corrosive and stable PEDOT with comparable performance to PEDOT:PSS remains a great challenge in the field. Herein, a solid n‐PEDOT:POM powder with neutral pH is synthesized by utilizing polyoxometalate (POM) as an oxidizing reagent, which exhibits excellent water solubility, high chemical stability, and superior hole collection ability. Impressively, an amazing fill factor of 0.80 along with a photovoltaic efficiency of 17.62% is obtained in the OSC by using n‐PEDOT:POM as the HTL, suggesting an exceptional hole collection ability for n‐PEDOT:POM. In addition, the neutral pH of PEDOT:PSS effectively improves the long‐term stability of OSCs. X‐ray photoelectron spectroscopy results reveal that, compared to the electrode/PEDOT:PSS interface, the permeation of dissociative indium from the electrode to n‐PEDOT:POM can be greatly retarded, which proves the non‐corrosive effect of n‐PEDOT:POM and its improvement of device stability. The successful preparation of a non‐corrosive and stable PEDOT derivative without sacrificing its hole collection ability provides the most fruitful new insight into developing high‐performance HTL materials.

Room temperature deposited silver oxide films by dc magnetron sputtering with high sputtering power: effect of deposition time on microstructure, electrical and optical properties

A series of non-stoichiometric p-type silver oxide (AgxO) films are room temperature deposited on glass substrates at different deposition time (td) by dc magnetron sputtering with high sputtering power. The evolution in component and the change in electrical and optical properties of the films with td are studied by XRD, SEM, EDS, visible-infrared spectroscopy and Hall data. The p-type conduction of cubic AgO and Ag2O phases is also proposed in mechanism. The evolution in component from AgO to almost Ag2O and the change in microstructure with td are caused by the thermal decomposition of AgO phase induced by high sputtering power. The film’s absorption edge firstly redshifts from 2.8 to 2.3 eV with increase of td from 2 min to 15 min, and then is suddenly reduced to 1.25 eV of cubic phase Ag2O at 20 min td. The phases AgO and Ag2O both have p-type conduction characteristics, mainly due to the Ag vacancies and O vacancies, respectively. The free carrier concentration and the resistivity of the films are both increased and reduced with increase of td. The AgxO film with 15 min td is the highest in p-type conduction ability due to the highest free carrier concentration and mobility, and thus is capable of being the candidate of hole-transporting layer materials of perovskite solar cells.

The Hole Transport Layer Material Optimization for an Efficient Lead-Free Double Perovskite Cs2AgBiBr6 Based Solar Cell by Numerical Simulation

The Hole Transport Layer Material Optimization for an Efficient Lead-Free Double Perovskite Cs2AgBiBr6 Based Solar Cell by Numerical Simulation

Supervised Machine Learning-Aided SCAPS-Based Quantitative Analysis for the Discovery of Optimum Bromine Doping in Methylammonium Tin-Based Perovskite (MASnI3-xBrx).

In this investigation, supervised machine learning (ML) was utilized to accurately predict the optimum bromine doping concentration in single-junction MASnI3-xBrx devices. Data-driven optimizations were carried out on 42 000 unique devices built utilizing a solar cell capacitance simulator (SCAPS). The devices were investigated through variations of bromine doping %, bandgap, electron affinity, series resistance, back-contact metal, and acceptor concentration─parameters that were specifically chosen because of their tunable nature and ability to be modified through facile experimental fabrication techniques of the device. Five different algorithms were utilized to explore feature engineering. The first step before bromine doping within the device included validation studies of a pure tin-based system, MASnI3: a power conversion efficiency (PCE) of 6.71% was achieved, having close congruence with experimental data. ML analyses for optimal bromine doping resulted in the discovery of two devices with bromine concentrations of 22.43% (Br22) and 25.63% (Br25), with the latter being a more fine-tuned value obtained through extra rigorous analysis. To understand the total and relative impact of each feature on power conversion efficiency (PCE), Br22 and Br25 were analyzed with a state-of-the-art algorithm, namely, the SHapley Additive exPlanations (SHAP) algorithm. Focusing on the two discovered devices, further device optimizations were carried out utilizing SCAPS. Modulations of absorber thickness, bulk and interfacial defect density, and choice of electron transport layer (ETL) and hole transport layer (HTL) materials were tried. Device stability was analyzed through carrier lifetime studies. Following these optimization steps, Br22 and Br25 demonstrated final high PCE values of 20.72 and 17.37%, respectively. The ML-assisted quantitative analysis of the current work provides significant confidence for optimal bromine-doped tin-based devices to be considered as viable and competitive nontoxic alternatives to traditional technologies.

Facile solution-processed molybdenum oxide as hole transporting material for efficient organic solar cell

The large energy barrier in hole extraction still remains a great challenge in developing hole transporting layer (HTL) materials for organic solar cells (OSCs). Thus, solution-processed HTL materials with excellent hole collection ability and good compatibility with large-area processing technique are strongly desired for OSCs. Herein, we developed a cost-effective and solution-processed MoO3 HTL for efficient OSCs. By adding a small amount of glucose as reducing reagent into the ammonium molybdate precursor solution, a deeply n-doped MoO3, namely G:Mo, was prepared through the sol–gel method. Compared to pristine MoO3, the conductivity of G:Mo was enhanced by two orders of magnitude, which greatly improved the hole collection ability of the HTL. OSCs with G:Mo can exhibit comparable PCE to the PEDOT:PSS device. Using PBDB-TF:BTP-eC9 as the active layer, a PCE of 17.1% is obtained for the device, which is the highest PCE value for OSC using a solution-processed MoO3 HTL. More importantly, G:Mo is well compatible with the blade-coating processing. The OSC using a blade-coated G:Mo showed almost no PCE loss as compared to the device with spin-coated G:Mo HTL. The results from this work indicate that G:Mo is a promising HTL material for the practical production of OSCs.

Performance Enhancement of Environmental Friendly Ge‐Based Perovskite Solar Cell with Zn3P2 and SnS2 as Charge Transport Layer Materials

Perovskite solar cell (PSC) may become the foundation of the photovoltaic industry in the future as it possesses unique photovoltaic properties that are not found in other solar cells. The primary impediment to the commercialization of lead‐based PSC devices is their toxicity and stability. In this scenario, the photovoltaic parameters of a nonpolluting methyl ammonium germanium halide (CH3NH3GeI3) PSC device are investigated using numerical modelling. Herein, different hole transport layer materials (HTPLMs) and electron transport layer materials (ETPLMs) are compared for the structure of germanium perovskite photovoltaic cells, and a suitable novel design FTO/SnS2/CH3NH3GeI3/Zn3P2/Au is chosen. Evaluating factors like thickness, defect density of the CH3NH3GeI3, Zn3P2, and Zn3P2 layer, interface defect density of HTPLM/perovskite and ETPLM/perovskite, and the consequence of series and shunt resistance are all evaluated, and the optimal value is calculated. The results show that perovskite photovoltaic cells based on the Germanium structure have a power conversion efficiency (PCE) of 25.98%, open‐circuit voltage = 1.26 V, current density = 23.781 mA cm−2, and a fill factor of 86.70%. Furthermore, the temperature study analysis shows that the device's PCE decreases to 23.72% at 390 K.

Optimization of Hole Transport Layer Materials for a Lead‐Free Perovskite Solar Cell Based on Formamidinium Tin Iodide

Recently, lead‐based perovskite solar cells have been mainly studied; however, these cells suffer from two main problems: the toxicity of lead and the instability of the devices, which limit their commercialization. Herein, a theoretical investigation of a lead‐free perovskite solar cell based on formamidinium tin iodide (HC(NH2)2SnI3) with the general architecture: glass/FTO/WS2/HC(NH2)2SnI3/HTL/Au is reported. All calculations are performed with the SCAPS‐1D solar cell simulator. Two inorganic (CuSCN and Cu2O) and two organic (P3HT and D‐PBTTT‐14) hole transport layer (HTL) materials are tested in this model. The effect of the external operating temperature and different metal work functions of the back contact of the cell on the overall performance of the devices is also studied. Simulations showed that, with the introduction of CuSCN, Cu2O, and P3HT as HTLs, the device can attain a remarkable efficiency of ≈21%. All the modeled devices showed remarkable performance of above 20% at higher temperatures of 380–420 K but degraded slightly when this range is exceeded. Relatively cheaper Pt, Ni, and Pd metals perform better, thus, can replace gold. These simulation results can provide avenues and directions for future advancement of the performance of lead‐free perovskite solar cells.

Simulation studies on the electron transport layer based perovskite solar cell to achieve high photovoltaic efficiency

Perovskite solar cells have attracted the attention of the researchers in the last couple of years as a potential photovoltaic device. However, the use of expensive hole transport materials (HTM) in these devices often restricts their commercial adaptability. Thus exploring cost-effective, efficient HTL and ETL materials remain an important challenge to the researchers. In this work, simulation studies are carried out considering cupric oxide (CuO), a relatively inexpensive material as hole transport materials for planar heterojunction perovskite solar cells. The photo-voltaic performance of CuO based hole transport layer (HTL) has been estimated in combination with several electron transport materials (ETM) that include TiO2,SnO2,ZnO, CdS, ZnSe,PCBM and Cd1-xZnxS. Studies predict that among these materials, the Cd1-xZnxS electron transport layer (ETL) could be the most promising to result high photo-voltaic efficiency in combination to CuO based HTL. Also, the thickness and optical band gap of perovskite absorber are optimized in order to achieve maximum photo-voltaic efficiency. The cell efficiency of FTO / Cd1-xZnxS/CH3NH3PbI3/CuO/carbon structure is predicted 25.24% under optimized operational conditions with Voc, Jsc and Fill Factor of 1.1eV,26.32mA/cm2 and 87.14% respectively.

Optimization of Lead Base Perovskite Solar Cell with ZnO and CuI as Electron Transport Material and Hole Transport Material Using SCAPS-1D

Perovskite solar cells (PSCs) research is substantially drawing attention because of the fast improvement in their power conversion efficiency (PCE), cheapness, possibility to tune the bandgap, low recombination rate, high open circuit voltage, excellent ambipolar charge carrier transport and strong and broad optical absorption. In this research, Zinc oxide as electron transport material (ETM) and copper iodide as hole transport material (HTM) have been optimized using SCAPS-1D simulation software. The thickness, bandgap, of ZnO (ETM) and CuI (HTM) was investigated. Results shows that the thickness and bandgap were found to strongly influence the PCE of perovskite solar cell. ZnO/CuI was found to be a better replacement to TiO2/Cu2O for stability and low degradation rate. It was observed that the maximum efficiency is 22.04%, Voc of 0.84V, JSC of 32.83mA/cm2 and FF of 79.79% was obtained when the thickness of ETM and HTM layer of (CH3NH3PbI3) PSCs which was found to be optimum at 0.2μm for the final optimization.

Improved Hole Extraction Selectivity of Polymer Solar Cells by Combining PEDOT:PSS with WO3

As the device performance and stability of polymer solar cells strongly depend on the interfacial charge extraction layers, the hole transport layer (HTL) properties are crucial. Furthermore, unfavorable interactions with the electrode or the photoactive layer should be screened and prevented. Organic solar cells of conventional architecture by varying the HTL material and layer stack systematically between PEDOT:PSS and a sol–gel‐derived tungsten oxide (WO3) are investigated. The impact of various HTLs in the solar cells is investigated by optical and electrical characterization. Interestingly, a triple‐layer WO3/PEDOT:PSS/WO3 configuration results in the best device performance specifically compared with the use of pristine WO3 and pristine PEDOT:PSS hole extraction layers. The triple layer also shows an increased reproducibility in the lifetime, which, combined with the improvement in the efficiency, can be the keys for expectable revenue.

Mini-Review on Efficiency and Stability of Perovskite Solar Cells with Spiro-OMeTAD Hole Transport Layer: Recent Progress and Perspectives

Organic–inorganic metal halide perovskite solar cells (PSCs) are one of the emerging technologies in photovoltaic research. The certified maximum power conversion efficiency (PCE) of PSCs has reached as high as 25%. In particular, the development of hole transport layer (HTL) materials plays a key role in increasing PCEs. Among a vast number of HTL materials developed to date, the most common HTL material is 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (spiro-OMeTAD), because it can provide very high performance in PSCs. Besides the high PCE, the issue of long-term stability is of paramount importance. The room-temperature operational stability of PSCs with the spiro-OMeTAD HTL has been improved significantly past few years, but it is still low, compared with Si-based technology. In addition, the instability at high temperature is the Achilles heel of PSCs with the spiro-OMeTAD HTL. Although the low operational stability of PSCs, especially at high temperature, is generally associated with instability of spiro-OMeTAD, the high-temperature stability has been improved significantly by understanding the degradation mechanisms. In this mini-review, we discuss the degradation mechanisms and suggest our perspectives to overcome the degradation. Thus, this mini-review will guide the development of stable PSCs with the spiro-OMeTAD HTL and the design of new HTL materials to replace spiro-OMeTAD toward commercialization of PSCs in the future.

Analysis of Hybrid Hetero-Homo Junction Lead-Free Perovskite Solar Cells by SCAPS Simulator

In this work, we report on the effect of substituting the active intrinsic i-layer on a conventional pin structure of lead-free perovskite solar cell (PSC) by a homo p-n junction, keeping the thickness of the active layer constant. It is expected that when the active i-layer is substituted by a p-n homo junction, one can increase the collection efficiency of the photo-generated electrons and holes due to the built-in electric field of the homo junction. The impact of the technological and physical device parameters on the performance parameters of the solar cell have been worked out. It was found that p-side thickness must be wider than the n-side, while its acceptor concentration should be slightly lower than the donor concentration of the n-side to achieve maximum efficiency. In addition, different absorber types, namely, i-absorber, n-absorber and p-absorber, are compared to the proposed pn-absorber, showing a performance-boosting effect when using the latter. Moreover, the proposed structure is made without a hole transport layer (HTL) to avoid the organic issues of the HTL materials. The back metal work function, bulk trap density and ETL material are optimized for best performance of the HTL-free structure, giving Jsc = 26.48, Voc = 0.948 V, FF = 77.20 and PCE = 19.37% for AM1.5 solar spectra. Such results highlight the prospective of the proposed structure and emphasize the importance of using HTL-free solar cells without deteriorating the efficiency. The solar cell is investigated by using SCAPS simulator.

Antioxidation and Energy-Level Alignment for Improving Efficiency and Stability of Hole Transport Layer-Free and Methylammonium-Free Tin-Lead Perovskite Solar Cells.

Tin-lead (Sn-Pb) perovskites have shown great potential in applications of single-junction perovskite solar cells (PSCs) and tandem devices due to outstanding photoelectrical properties and low band gaps. Currently, Sn-Pb PSCs typically have a p-i-n structure, but choices of hole transport layer (HTL) materials are very limited and there are different concerns in each of them. Eliminating the HTL is a direct and promising strategy to address the concerns, but is rarely studied. In this work, we demonstrate HTL-free and MA-free based Sn-Pb PSCs and a synergistic integration strategy of simultaneously introducing a reducing agent and in situ surface passivation. With the integration strategy, Sn-Pb perovskite films with enhanced antioxidation, reduced trap density, prolonged carrier lifetime, and improved energy-level alignment are achieved. Consequently, final HTL-free PSCs exhibit a champion power conversion efficiency (PCE) of 17.4%, which is a new record for HTL-free and MA-free Sn-Pb PSCs. Meanwhile, the integration strategy-based HTL-free device maintains excellent stability with efficiency unchanged for the first 200 h, and finally retaining 81% of the efficiency after 480 h aging in the air. This study shows the potential of achieving desirable HTL-free and MA-free Sn-Pb PSCs and offers more opportunities for tandem solar cells and other photovoltaic devices.