Free Perovskite Solar Cells Research Articles

Perspective on machine learning based investigated materials to realize Stable-Efficient-Toxin free (S-E-T) perovskite solar cells

The progress of third generation hybrid organic–inorganic metal-halide Perovskite Solar cells, widely-opened new doors for the researchers globally. The benefits of Perovskite Solar cells (PSC) such as high light absorption coefficient, easy preparation and low cost makes it the best in purpose at marketing level, but challenges on improving stability of the Perovskite solar cell makes it the secondary option compared to the conventional solar cells. Theimproved rate of change of power conversion efficiency (PCE) from 3.8 % (year 2009) to 22.1% (year 2016) to above 25% in 2022, made perovskitesolar cells the prominent choice for switching from conventional solar cells to new generation solar cells. In this paper, we condense the studies of ML investigated PSC’s over the past decade, for realizingmaterials that produceStable-Efficient- Toxin free (S-E-T) PSC. Some of the most applicable combinations of PSC’s are discussed that can be fabricated to verify the end-results with ML investigations.

Fullerene modification of WO3 electron transport layer toward high‐efficiency MA‐free perovskite solar cells with eliminated light‐soaking effect

AbstractIn perovskite solar cells (PSCs), the light‐soaking effect, which means device performance changes obviously under continuous light illumination, is potentially harmful to loaded devices as well as accurately assessing their efficiency. Herein, chemically stable tungsten trioxide (WO3) with high electron mobility is used as electron transport material in methylamine (MA)‐free PSCs. However, the light‐soaking effect is observed apparently in our devices. A fullerene derivative, C60 pyrrolidine Tris‐acid (CPTA), is introduced to modify the interface between WO3 and perovskite (PVK) layers, which can bond with WO3 and PVK simultaneously, leading to the passivation of the defect and the suppression of trap‐assisted nonradiative recombination. What is more, the introduction of CPTA can enhance the built‐in electric field between WO3 and PVK layers, thereby facilitating the electron extraction and inhibiting the carrier accumulation at the interface. Consequently, the light‐soaking effect of WO3‐based PSCs has been eliminated, and the power conversion efficiency has been boosted from 17.4% for control device to 20.5% for WO3/CPTA‐based PSC with enhanced stability. This study gives guidance for the design of interfacial molecules to eliminate the light‐soaking effect.

Numerical investigation of toxic free perovskite solar cells for achieving high efficiency

Increasing efficiency, simple and inexpensive fabrication process and flexibility nature of organic metal halide perovskite (PVK) based solar cell has fascinated the researchers around the globe. However, Lead, a poisonous substance in PVK solar cell causes various issues which directly or indirectly impact the environment as well as the health of living things. It prevents the commercialization of PVK based solar cell. To overcome this, a number of lead-free perovskite solar cell has been designed and fabricated. But the conversion efficiency is still not up to par because of intrinsic losses. In order to improve the efficiency, a thorough theoretical investigation is required that can reveal the cause behind these losses. In this study a special PVK material named methylammonium tin iodide (MASnI3) is used in simulation platform to design a highly efficient organic lead-free solar cell. This study focuses on the optimization of active layer thickness, working temperature, capacitance-voltage (C-V), and impedance and defect density, as they plays major roles in determining the performance of toxic free organic PVK solar cell. The study confirms an high efficiency (η) of 24.22% at the optimized condition. Such high efficiency with an optimized structure can open a door for the commercialization of lead free PVK based solar cell.

Bulk Incorporation with 4‐Methylphenethylammonium Chloride for Efficient and Stable Methylammonium‐Free Perovskite and Perovskite‐Silicon Tandem Solar Cells

AbstractMethylammonium (MA)‐free perovskite solar cells have the potential for better thermal stability than their MA‐containing counterparts. However, the efficiency of MA‐free perovskite solar cells lags behind due to inferior bulk quality. In this work, 4‐methylphenethylammonium chloride (4M‐PEACl) is added into a MA‐free perovskite precursor, which results in greatly enhanced bulk quality. The perovskite crystal grains are significantly enlarged, and defects are suppressed by a factor of four upon the incorporation of an optimal concentration of 4M‐PEACl. Quasi‐2D perovskites are formed and passivate defects at the grain boundaries of the perovskite crystals. Furthermore, the perovskite surface chemistry is modified, resulting in surface energies more favorable for hole extraction. This facile approach leads to a steady state efficiency of 23.7% (24.2% in reverse scan, 23.0% in forward scan) for MA‐free perovskite solar cells. The devices also show excellent light stability, retaining more than 93% of the initial efficiency after 1000 h of constant illumination in a nitrogen environment. In addition, a four‐terminal mechanically stacked perovskite‐silicon tandem solar cell with champion efficiency of 30.3% is obtained using this MA‐free composition. The encapsulated tandem devices show excellent operational stability, retaining more than 98% of the initial performance after 42 day/night cycles in an ambient atmosphere.

Hole transport layer-free carbon-based perovskite solar cells with high-efficiency up to 17.49% in air: From-bottom-to-top perovskite interface modification

Low-cost hole transport layer (HTL)-free carbon-based perovskite solar cells (C-PSCs) have drawn considerable interest owing to their simple manufacturing process and excellent stability. However, the insufficient interfacial charge transport severely limits the efficiency of HTL-free C-PSCs. In this paper, a from-bottom-to-top dual interfacial modification (DIM) strategy is developed by adopting FAX (X = I, Br) to modify perovskite interfaces and thus to intensify charge transport at SnO2/perovskite and perovskite/carbon interfaces. The underlying FABr is employed to regulate the composition at the bottom region of the perovskite films by the reaction of FABr and its upper PbI2 & MAI, yielding a favorable band alignment at SnO2/perovskite. The FAI is used to fill the gaps at upper perovskite/carbon interface to boost the two-layer contact via the penetration of FAI across carbon electrode, and subsequent reaction with the residual PbI2. Such dual-modified perovskite films exhibit improved crystallinity and thus reduced trap state density. On account of the above merits, the dual-modified HTL-free C-PSCs with an architecture of ITO/SnO2/perovskite/carbon present a power conversion efficiency up to 17.49 % in air. Moreover, the C-PSCs exhibit superior ambient stability maintaining 96 % of its initial performance under storage in ambient air condition up to 60 days due to carbon electrode being filled by the penetrated FAI against the moisture erosion.

Eco-friendly methyl-ammonium tin-based planar p–n homojunction Perovskite solar cells: Design and performance estimation

In this study, the design and performance estimation of tin (Sn)-based planar [Formula: see text]–[Formula: see text] homojunction perovskite solar cell (PSC) have been carried out. Here, the effect of maintaining the intrinsic active layer thickness and replacing the intrinsic active perovskite [Formula: see text]-layer of a standard [Formula: see text]-[Formula: see text]-[Formula: see text] structure of lead (Pb)-free PSCs with a [Formula: see text]–[Formula: see text] homojunction is fully investigated. When the active layer is divided into a [Formula: see text]–[Formula: see text] junction layer, it increases the photo-generated electrons and holes efficiency due to the built-in electric field of the junction. Furthermore, in order to get a better insight, the effects of various technological and device dimensional parameters on the performance of the reported PSC have been studied. It has been reported that the thickness of the p-side with methyl-ammonium tin triiodide (MASnI[Formula: see text] layer must be greater than the n-side of the MASnI3 layer. Meanwhile, its acceptors concentration should be slightly lower than the donors’ concentration on the n-side of MASnI3 layer to achieve maximum power conversion efficiency (PCE). Using the optimized parameters, our design demonstrates an open-circuit voltage ([Formula: see text] of 0.89 V, short-circuit current density ([Formula: see text] of 32.36 mA/cm2, fill factor (FF) of 74.40%, and PCE of 21.46%. This advocates the huge potential and great opportunities for deploying these Pb-free PSCs for eco-friendly photovoltaic applications.

Investigation of photovoltaic performance of lead-free CsSnI3-based perovskite solar cell with different hole transport layers: First Principle Calculations and SCAPS-1D Analysis

Perovskite solar cells (PSCs) are getting maximum consideration among the research community because of the abrupt rise in their power conservation efficiency (PCE) to 25.5 % within a short span of time. However, the toxicity of the more dominating lead (Pb) based perovskites has been a major obstacle in the path of its commercialization. In this study, we have performed a systematic investigation of the photovoltaic (PV) properties of Pb- free PSCs, consisting of an excellent thermally stable Cesium Tin Iodide (CsSnI3) as an absorber layer. We have explored the impact of three common hole transport layers (HTLs) namely poly(3-hexylthiophene-2,5-diyl) (P3HT), poly(3,4-ethylenedioxythiophene) (PEDOT: PSS) and (2,2′,7,7′-Tetrakis [N, N-di(4-methoxyphenyl) amino]-9,9′-spirobifluorene) (Spiro-OMeTAD) on the performance metrics of the PSCs. The impact of thickness variation, doping density, and defect density of the absorber layer on the PV parameters namely the short circuit current density (Jsc), open circuit voltage (Voc), PCE and Fill Factor (FF) is also examined. Our proposed device comprising of a planer p-n heterojunction structure with p-type CsSnI3 as absorber layer (FTO/n-TiO2/p-CsSnI3/p-HTL) is simulated using SCAPS-1D. WIEN2K software is used to calculate the electrical and optical characteristics of the absorber layer. We found that the P3HT-based device (FTO/n-TiO2/p-CsSnI3/p-P3HT) shows the highest PCE of 26.40 % with FF of 78.21 %, Voc of 0.972 V, and Jsc of 34.70 mA/cm2. The outcomes and interpretation of this paper show that the possibility of achieving a high PCE perovskite device can be attained utilizing safe, and non-toxic materials like CsSnI3.

Hole-Transport Layer-Free Tin-Based Perovskite Solar Cells: Improving Their Performance from a Simulation Perspective

Perovskite solar cells are in rapid development, however, PCE (photovoltaic conversion efficiency) of HTL-free (Hole Transport Layer free) perovskite solar cells is reported to be low. In this work, we propose a tin-based perovskite solar cell with an ETL (Electron Transport Layer) structure of a novel electron transport layer material. We simulated the device with SCAPS-1D (Solar Cells Capacitance Simulator) and found that all of the absorber layer thickness, band gap, doping concentration, defect density, device working temperature, ETL layer thickness, and doping concentration have different degrees of influence on the device performance. After optimization, (Open Circuit Voltage) is 1.07 V, (Short-circuit Current Density) is 24.25 FF (Filling Factor) is 87.87%, and PCE arrives up to 22.72%. There is a significant performance improvement compared to pre-simulation (initially, is 0.97 V, is 24.21 FF is 69.12%, and PCE is 16.22%). It is shown that when the thickness of the absorber layer is larger than the diffusion length, it leads to harmful photogenerated carrier complexes and increases the diffusion length before reaching the electrode, which affects the carrier transport migration. Defect density bears the brunt of the performance impact, the greater it is the worse the performance, so it should be controlled to a small range. When the operating temperature higher than 300 K, the device performance tends to deteriorate and it is recommended to keep the operating temperature around 300 K. The ETL layer doping concentration and thickness have little influence on performance. Finally, we also analytically simulate and compare several traditional ETL PSCs, and the matching of LUMO (Lowest Unoccupied Molecular Orbital) and absorber energy levels of different ETL materials was found to be different, and the higher the matching is, the more favorable the electron transport and the higher the PCE. This work provides new strategy to design PSCs.

Efficient hole extraction with Eu3+-doped CsPbBr3 QD interface modification for HTL-free CH3NH3PbI3:Na perovskite solar cells

Hole transport layer free perovskite solar cells (HTL-Free PSCs) have attracted extensive attention due to their advantages of simple structure and low cost. However, due to the serious energy level mismatch caused by the direct contact between the perovskite layer and the opposite electrode, the space for improving the efficiency of HTL-Free PSCs is greatly limited. We use Eu3+ doped CsPbBr3 quantum dots (QD) to modify the interface between MAPbI3:Na layer and C electrode, and study its effect on the surface defect passivation, interface energy level arrangement and carrier transport behavior in the device. It was found that compared with the interfacial modification of CsPbBr3 QD alone, the interfacial modification of CsPbBr3:Eu QD could effectively solve the problem of energy level mismatch in HTL-Free PSCs, resulting in a remarkable improvement of conversion efficiency from 9.01 % to 12.95 %. Furthermore, electron beam induced current (EBIC) was used to prove that CsPbBr3:Eu QD interface modification significantly improved the hole collection ability. This provides an experimental basis and theoretical guidance for the optimization of the efficiency of other types of transport layer free photovoltaic devices.

Recent advances in lead-free based perovskite solar cells on optoelectronic properties, stability and economic feasibility

The present review article represents the scope of different lead (Pb)-free hybrid halide Perovskite solar cells (PSC) for photovoltaic (PV) applications. Research on lead-free material is emerging mainly to identify the alternatives of lead in the Perovskite solar cells. Several homovalent (Sn2+, Ge2+, Cu2+) and heterovalent (Sb3+, Bi3+, Ti4+) materials have good physical properties to replace the lead content in the absorbing material compound. However the power conversion efficiency (PCE, %) is not higher as compared to lead based material. This review article focuses on the characteristics, material properties, stability and performance of the different Pb-free materials as absorbing layer in the Perovskite solar cells.

Facile NaF Treatment Achieves 20% Efficient ETL-Free Perovskite Solar Cells.

Electron transporting layer (ETL)-free perovskite solar cells (PSCs) exhibit promising progress in photovoltaic devices due to the elimination of the complex and energy-/time-consuming preparation route of ETLs. However, the performance of ETL-free devices still lags behind conventional devices because of mismatched energy levels and undesired interfacial charge recombination. In this study, we introduce sodium fluoride (NaF) as an interface layer in ETL-free PSCs to align the energy level between the perovskite and the FTO electrode. KPFM measurements clearly show that the NaF layer covers the surface of rough underlying FTO very well. This interface modification reduces the work function of FTO by forming an interfacial dipole layer, leading to band bending at the FTO/perovskite interface, which facilitates an effective electron carrier collection. Besides, the part of Na+ ions is found to be able to migrate into the absorber layer, facilitating enlarged grains and spontaneous passivation of the perovskite layer. As a result, the efficiency of the NaF-treated cell reaches 20%, comparable to those of state-of-the-art ETL-based cells. Moreover, this strategy effectively enhances the operational stability of devices by preserving 94% of the initial efficiency after storage for 500 h under continuous light soaking at 55 °C. Overall, these improvements in photovoltaic properties are clear indicators of enhanced interface passivation by NaF-based interface engineering.

Lead free efficient perovskite solar cell device Optimization and defect study using Mg doped CuCrO2 as HTL and WO3 as ETL

An n-i-p architecture perovskite solar cell (PSC) has been suggested and modelled employing Pb free CH3NH3SnI3 absorber layer. A relative investigation for WO3 (ETL) and Mg-CuCrO2 (HTL) with different thickness, carrier concentration, interfacial layer (IL) defect tolerance factor, impact of temperature on device performance have been portrayed by SCAPS-1D simulator. A lower thickness of ETL and HTL is quite effective to produce better efficiency. The proposed FTO/WO3/CH3NH3SnI3/Mg-CuCrO2/Au device shows the maximum Voc, Jsc, FF and PCE of 1.02 V, 37.95 mA/cm2, 71.38 %, 27.53 %, respectively. The carrier concentrations NA and ND were optimized at 1x1014cm-3 and 1x1016cm-3. After those ideals, the projected PSC device’s photovoltaic presentation was considerably reduced. The interfacial layer 1 (IL1) and interfacial layer 2 (IL2) exhibited the defect tolerance level of 1x1011cm-2 and 1x1016cm-2, respectively. It was found that Au as a back-contact could produce the highest PCE among other back contact metals. The ambient temperature proved to be ideal one to generate the highest PCE since elevated temperatures lead to reduce Voc and PCE thereby. The suggested ETL and HTL have been proved to be alternative inorganic charge transporting materials which could regulate the device performance as well as stability into the environmental atmosphere.

Role of built-in potential over ETL/perovskite interface on the performance of HTL-free perovskite solar cells

Lead-free, Sn-based perovskite solar cells (PvSCs) have piqued the interest of researchers and their commercialization. Hole transport layer (HTL)-free PvSCs are low-cost and easy to fabricate. The built-in potential of a photovoltaic (PV) device plays an essential role in the separation of light-generated charge carriers. In this simulation work, we have investigated the built-in potential at the interface of electron transport layer (ETL) and Formamidinium tin iodide (FASnI3) with the help of Mott-Schottky plot for various types of ETLs. We have measured how the built-in potential was affected by thickness, doping density, and defect density of FASnI3 perovskite absorber layer and found that the built-in potential of ETL/FASnI3 interface had a significant impact on the device performance parameters. The built-in potential greatly affects the Shockley-Read-Hall (SRH) recombination mechanism. In this simulation, the material parameters of each layer have been optimized and obtained an optimized PCE of more than 16% for all devices. It is anticipated that the results of this study have great potential to understand the role of built-in potential in n-p junction PV devices and consequently device optimization of not only for HTL-free FASnI3-based PvSCs but also for other single n-p junction PvSCs. However, the fabrication of HTL-free FASnI3-based PvSCs is still a challenging task due to the oxidation of Sn2+ to Sn4+.

Construction of multilevel network structured carbon nanofiber counter electrode and back interface engineering in all inorganic HTL–free perovskite solar cells

Carbon materials are potential counter electrodes for all−inorganic hole transport layer (HTL)−free perovskite solar cells (PSCs), whereas the defects of the perovskite/carbon back interface are the dominant reason for the low power conversion efficiency (PCE) of this kind of device. To resolve this problem, carbon nanofiber (CNF) was first synthesized using electrospinning technique to construct a carbon counter electrode with porous network architecture by self−supporting nature of CNF. The CsPbBr3 based all−inorganic HTL−free PSCs using the porous CNF counter electrode shows a PCE of 5.01%. To further modify the CsPbBr3/carbon back interface and energy level alignment, mesoporous CNF (m−CNF) and B doped m−CNF (m−BCNF) are synthesized, which can improve the conductivity of the carbon counter electrodes as well as decline the trap state densities and accelerate the carrier extraction and transport properties of the back interface. Accordingly, the all inorganic HTL−free PSCs using m−CNF and m−BCNF counter electrodes generate high PCE of 7.48% and 8.38%, with outstanding long−tern stability. The enhanced PCE improvements can be ascribe to strategies of construction of multilevel network and B doping which can modify the CsPbBr3/carbon back interface, optimize the energy level alignment of the device, and enhance the conductivity of the carbon counter electrode. This research is expected to provide meaningful support for development of new counter electrode materials and back interface engineering for high-performance all inorganic HTL−free PSCs.

Numerical simulation and fabrication of Pb-free perovskite solar cells (FTO/TiO2/Cs3Bi2I9/spiro-MeOTAD/Au)

Recently, lead (Pb)-free perovskite solar cells (PSCs) have received enormous attention and various Pb-free perovskite and perovskite-like materials have been employed as light absorber for photovoltaic applications. Cesium bismuth iodide (Cs3Bi2I9) is stable and less toxic perovskite-like material. Herein, we have simulated Cs3Bi2I9 based Pb-free PSCs with device architecture of FTO/TiO2/Cs3Bi2I9/spiro-MeOTAD/Au using SCAPS-1D software. The influence of thickness of electron transport layer (ETL), hole transport material (HTM) and light absorber layer (Cs3Bi2I9) were investigated. The best simulated Pb-free PSCs exhibited the highest power conversion efficiency of 11.54%. Further, we have prepared thin films of Cs3Bi2I9 and physiochemical properties were examined by X-ray diffraction (XRD) and optical band gap was determined by employing ultraviolet–visible (UV–vis) absorption spectroscopy. We have also fabricated Pb-free PSCs with device structure of FTO/TiO2/Cs3Bi2I9/spiro-MeOTAD/Au. The fabricated Pb-free PSCs device exhibited good open circuit voltage (Voc) of 780 mV with PCE of 1.66%.

Optoelectronic and Photovoltaic Properties of (NH4)3Bi2I9: A Perovskite‐like Energy Material for Pb‐free Perovskite Solar Cells

AbstractRecent few years have witnessed a tremendous surge in the design and fabrication of lead (Pb)‐free perovskite or perovskite‐like materials for the development of perovskite solar cells (PSCs). Bismuth halide perovskite materials such as (CH3NH3)3Bi2I9, Cs3Bi2I9 and FA3Bi2I9 have been utilized as highly efficient perovskite light absorbers in terms of aerobic stability. Herein, we have investigated the optoelectronic properties of the (NH4)3Bi2I9 perovskite and employed as light absorber in the construction of Pb free PSCs. Solvent engineering approach was utilized to improve the photovoltaic performance of the (NH4)3Bi2I9 perovskite based PSCs. The probable HOMO and LUMO energy level values of the (NH4)3Bi2I9 perovskite were also investigated and the band gap of the (NH4)3Bi2I9 perovskite was found to be of 2.1 eV. The developed PSCs device exhibited the power conversion efficiency (PCE) of ∼0.6%.

Numerical simulation of MASnI3/CuI heterojunction based perovskite solar cell

The lead (Pb) free perovskite solar cells have gained much attention due to non-toxic nature. Owing to a smaller band gap of 1.3 eV, methylammonium tin iodide (III) (MASnI3) can be considered an alternate light absorber layer compare to the lead-based perovskites (MAPbClxI3-x). In this article, MASnI3 based perovskite solar cell has been studied using a 1-D SCAPS simulator. The solar cell structure ITO/TiO2/MASnI3/CuI is simulated in superstrate configuration which achieves a photovoltaic efficiency less than 8 %. Photovoltaic efficiency of the solar cell is further improved to 17.93 % by optimizing thickness and total defect density of the absorber layer. Moreover, the role of defects at the interfaces: TiO2/MASnI3 and MASnI3/CuI on the solar cell performance is also analyzed.

Simulation and fabrication of all-inorganic antimony halide perovskite-like material based Pb-free perovskite solar cells

Recently, numerical simulation of lead (Pb)-free perovskite solar cells (LFPSCs) has attracted scientific community and received great attention. All-inorganic cesium antimony iodide (Cs3Sb2I9) which is perovskite-like material has been widely explored as light absorbing layer in the development of LFPSCs. In present work, we have reported the numerical simulation of LFPSCs with device architecture of FTO/TiO2/Cs3Sb2I9/spiro-OMeTAD/Au. The thickness of electron-transport layer (ETL), light absorber layer, and hole-transport layer (HTL) were optimized to achieve the highest efficiency. The optimized LFPSCs exhibited excellent efficiency of 12.54% using SCAPS-1D. Further, Cs3Sb2I9 films were obtained and their physiochemical and optical properties were examined by X-ray diffraction (XRD), scanning-electron spectroscopy (SEM), and ultraviolet–visible (UV–vis) absorption spectroscopy. Furthermore, LFPSCs device (FTO/TiO2/Cs3Sb2I9/spiro-OMeTAD/Au) was fabricated under controlled humidity (∼30–40%). The fabricated LFPSCs showed good efficiency of 1.07%.

Effect of Methylammonium Iodide on the All-solution Prepared Methylammonium Bismuth Iodide Perovskite Solar Cells Performance

The methylammonium bismuth iodide (MBI), a promising lead (Pb)-free perovskite solar cells (PeSC’s) material, is suitable for photovoltaic applications due to less toxic and good stability. Herein, the effect of MAI (methylammonium iodide) on the structural, morphological, optical properties and solar cells performance of bismuth-perovskite solar cells (Bi-PeSC’s) by all-solution processed multi-step spin coating is investigated. The scanning electron microscope (SEM) morphology visually depicts that with the increase of methylammonium iodide (MAI) precursor molar ratio in bismuth (III) iodide (BiI3) x [= [MAI]/([MAI]+[BiI3])] from x=0 to x=0.8, the morphological phase changed significantly. Likewise, the x-ray diffraction (XRD) peak of BiI3 at 12.78o (003) is tremendously changed in the phase and intensity. At the same time, the solar cell performances exhibit gradual increment as increasing the content of MAI in BiI3 and the open circuit voltage (Voc) is exceeded four-times of the minimum MAI molar ratio. The maximum Voc obtained by multilayer Bi-PeSC’s is 0.34V and an efficiency shows an increment up to 0.0037% at MAI molar ratio, x=0.8. In brief, our findings suggested the improvement of Bi-perovskite absorber layer in the future.

Employing 2D‐Perovskite as an Electron Blocking Layer in Highly Efficient (18.5%) Perovskite Solar Cells with Printable Low Temperature Carbon Electrode

AbstractInterface engineering and passivating contacts are key enablers to reach the highest efficiencies in photovoltaic devices. While printed carbon–graphite back electrodes for hole‐transporting material (HTM)‐free perovskite solar cells (PSCs) are appealing for fast commercialization of PSCs due to low processing costs and extraordinary stability, this device architecture so far suffers from severe performance losses at the back electrode interface. Herein, a 2D perovskite passivation layer as an electron blocking layer (EBL) at this interface to substantially reduce interfacial recombination losses is introduced. The formation of the 2D perovskite EBL is confirmed through X‐ray diffraction, photoemission spectroscopy, and an advanced spectrally resolved photoluminescence microscopy mapping technique. Reduced losses that lead to an enhanced fill factor and VOC are quantified by electrochemical impedance spectroscopy and JSC–VOC measurements. This enables reaching one of the highest reported efficiencies of 18.5% for HTM‐free PSCs using 2D perovskite as an EBL with a significantly improved device stability.