Perovskite Growth Research Articles

SN2-Reaction-Driven Bonding-Heterointerface Strengthens Buried Adhesion and Orientation for Advanced Perovskite Solar Cells.

Traditionally weak buried interaction without customized chemical bonding always goes against the formation of high-quality perovskite film that highly determines the efficiency and stability of perovskite solar cells. To address this issue, herein, we propose a bimolecular nucleophilic substitution reaction (SN2) driving strategy to idealize the robust buried interface by simultaneously decorating underlying substrate and functionalizing [PbX6]4- octahedral framework with iodoacetamide and thiol molecules, respectively. Theoretical and experimental results demonstrate that a strong SN2 reaction between exposed halogen and thiol group in two molecules occurs, which not only benefits the reinforcement of buried adhesion, but also triggers target-point-oriented crystallization, synergistically upgrading the upper perovskite film quality and accelerating interfacial charge extraction-transfer behavior. Benefiting from the suppressed nonradiative recombination, as a result, an all-air-processed carbon-based all-inorganic CsPbI2Br device achieves an enhanced efficiency of 15.14%, more importantly, with significantly prolonged long-term stability under harsh conditions. This unique reaction-driven buried interface provides a new path for manipulating perovskite growth and obtaining advanced perovskite photovoltaics.

Optimizing the light-humidity stability of formamidinium halide perovskites through intermediate phase and strain stress adjustment

Recently, the FA1-xCsxPbI3 system became popular due to its high performance and respectful thermal stability. However, the impact of Cs doping in the precursor on the stability of FA1-xCsxPbI3 perovskite films and devices remains unclear. Here, we systematically investigate the effects of trace amounts of Cs+ cations (<10%) on the intermediate phase, the crystallization and orientation, lattice strain and device stability of FA1-xCsxPbI3 perovskite. The results demonstrate that 5.0% Cs+ cations substitution for FA reduces the nucleation barrier of FAPbI3 and promotes the formation of the α-phase before heat treatment. And the Cs+ cations induce the oriented growth of FA1-xCsxPbI3 perovskite, eliminating unfavorable (110) facet and preventing the formation of unstable (100) facet at the top of perovskite. Meanwhile, 5.0% Cs+ cation substitution for FA effectively alleviates lattice strains in the perovskite structure, minimizing defects or traps recombination centers. Thus, the light and humidity stability of the FA0.950Cs0.050PbI3 device are substantially increased. The PCE of FA0.950Cs0.050PbI3 device remains ∼70% of the initial value after 768 hours under humidity exposure, and as a comparison, the FAPbI3 maintains only 54.5% of the initial value. The pure FAPbI3 device only maintains ∼25% of its initial value under 14 light-dark cycles, while the FA0.950Cs0.050PbI3 device maintains ∼75.1% of its initial value after 18 light-dark cycles. This work highlights the optimal threshold for Cs+ cation substitution for FA in FA1-xCsxPbI3 perovskite, contributing to the advancement of FA1-xCsxPbI3 high-performance perovskite solar cells.

Toward Efficient and Stable Ruddlesden‐Popper Perovskite: Unraveling the Selection Rule of Binary Spacer Cations

Abstract2D Ruddlesden‐Popper (RP) perovskites have excellent environmental stability and enhanced photostability compared with their 3D counterparts. However, the introduction of organic spacer cations induces disordered crystal growth and increased exciton binding energy, limiting the photoelectric performance. Here, a binary spacer cations engineering strategy is reported that incorporates aromatic and alkylamine spacer cations, in which fluorine‐substituted hydrocarbons (4‐TFBZAI) promotes carrier transport and alkylamine (BAI) assists the ordered growth of perovskite. The resulting binary spacer perovskite (4‐TFBZA1.6BA0.4)FA4Pb5I16 shows preferred orientational growth and reduced exciton binding energy, enabling an efficient photodetector with a detectivity exceeding 1013 Jones and a response time of 583 ns. The influence of the spacer cations with varying functional groups and chain lengths is examined. The results reveal that selecting long‐chain alkylamine to mix with aromatic spacer cations shall be based on considerations of both functional groups and chain length. The aromatic spacer cation with suitable groups enhances carrier transport, while the flexible long‐chain alkylamine facilitates perovskite crystal growth. Moreover, matched chain lengths between aromatic and alkylamine spacer cations are crucial to the photoelectric performance of RP perovskites. This work will guide researchers in selecting suitable binary spacer cations and designing new types of RP perovskites.

Reinforcing Coverage of Self-assembled Monomolecular Layers for Inverted Perovskite Solar Cells with Efficiency of 25.70 .

Self-assembled monolayers (SAM) as hole transport layers have been widely used in high-efficiency inverted perovskite solar cells (PSCs) exceeded 26 %. However, the poor coverage and non-uniform distribution on the substrate of SAM further restrict the improvement of device performance. Herein, we utilize the mixed SAM strategy via the MeO-2PACz along with perfluorotripropylamine (FC-3283) to improve the SAM coverage, aiming to accelerate the carrier transport, promote the perovskite growth, regulate the surface energy levels and suppress the nonradiative recombination. The champion device with the mixed-SAM achieves an efficiency of 25.70 % (certified efficiency of 25.6 %) with long-term stability (maintained the initial efficiency of 90 % after 1000 h and 180 h under ISOS-L-1 and ISOS-L-2).

Reinforcing Coverage of Self‐assembled Monomolecular Layers for Inverted Perovskite Solar Cells with Efficiency of 25.70%

Self‐assembled monolayers (SAM) as hole transport layers have been widely used in high‐efficiency inverted perovskite solar cells (PSCs) exceeded 26%. However, the poor coverage and non‐uniform distribution on the substrate of SAM further restrict the improvement of device performance. Herein, we utilize the mixed SAM strategy via the MeO‐2PACz along with perfluorotripropylamine (FC‐3283) to improve the SAM coverage, aiming to accelerate the carrier transport, promote the perovskite growth, regulate the surface energy levels and suppress the nonradiative recombination. The champion device with the mixed‐SAM achieves an efficiency of 25.70% (certified efficiency of 25.6%) with long‐term stability (maintained the initial efficiency of 90% after 1000 h and 180 h under ISOS‐L‐1 and ISOS‐L‐2).

Program-Modulated Kinetics of Perovskite-Film Growth by Molecular "Thruster" for High-Efficiency and Stable Perovskite Solar Cells.

The rapid reaction between lead iodide (PbI2) and formamidinium iodide (FAI) complicates the fabrication of high-quality formamidinium lead iodide (FAPbI3) films. Conventional methods, such as using nonvolatile small molecular additives to slow the reaction, often result in buried interfacial voids and molecule diffusion, compromising the devices' operational stability. In this study, we introduced a molecular "thruster"-a hypervalent iodine (III) compound with three carbonyl groups and a C--I+ bond-that possesses coordination and dissociation abilities, enabling programed modulation of perovskite-film growth kinetics. Initially, the three carbonyl groups coordinate with PbI2 to slow the reaction between FAI and PbI2, preventing δ-phase formation. As temperature rises, the C--I+ bond dissociates, promoting perovskite growth and the dissociated product iodobenzene will promote solvent volatilization, thus avoiding buried interfacial voids. Another product, a carbene compound with eight lone pair electrons sufficiently passivate the undercoordinated Pb2+ defects and anchors at grain boundaries without diffusion. Consequently, the resultant FAPbI3 film displays high-quality with enhanced phase purity, compact morphology, and reduced defects. Evidently, 0.062- and 1.004-cm2 pero-SCs achieve power conversion efficiencies (PCEs) of up to 26.06 % (25.79 % certified) and 24.65 %, respectively. This approach also controls perovskite-film growth on plastic substrates, resulting in flexible pero-SCs with an impressive PCE of 25.12 %.

Program‐Modulated Kinetics of Perovskite‐Film Growth by Molecular "Thruster" for High‐Efficiency and Stable Perovskite Solar Cells

The rapid reaction between lead iodide (PbI2) and formamidinium iodide (FAI) complicates the fabrication of high‐quality formamidinium lead iodide (FAPbI3) films. Conventional methods, such as using nonvolatile small molecular additives to slow the reaction, often result in buried interfacial voids and molecule diffusion, compromising the devices' operational stability. In this study, we introduced a molecular “thruster”—a hypervalent iodine (III) compound with three carbonyl groups and a C––I⁺ bond—that possesses coordination and dissociation abilities, enabling programed modulation of perovskite‐film growth kinetics. Initially, the three carbonyl groups coordinate with PbI2 to slow the reaction between FAI and PbI2, preventing δ‐phase formation. As temperature rises, the C––I⁺ bond dissociates, promoting perovskite growth and the dissociated product iodobenzene will promote solvent volatilization, thus avoiding buried interfacial voids. Another product, a carbene compound with eight lone pair electrons sufficiently passivate the undercoordinated Pb2+ defects and anchors at grain boundaries without diffusion. Consequently, the resultant FAPbI3 film displays high‐quality with enhanced phase purity, compact morphology, and reduced defects. Evidently, 0.062‐ and 1.004‐cm2 pero‐SCs achieve power conversion efficiencies (PCEs) of up to 26.06% (25.79% certified) and 24.65%, respectively. This approach also controls perovskite‐film growth on plastic substrates, resulting in flexible pero‐SCs with an impressive PCE of 25.12%.

Synergistic Doping Strategy with Novel Multi-Carbonyl Conductive Polymer Enables Stable Self-Powered Perovskite Photodetectors.

Lead halide perovskites hold immense promise for optoelectronic applications but still suffer from instability caused by defects. The defects are mainly generated from the film fabrication processes and halide ion migration during long-term storage. Here, a synergistic doping strategy is proposed to enhance the stability of perovskites. A novel multi-carbonyl conductive polymer, poly(benzodifurandione) (PBFDO), is incorporated into the precursor solution to effectively passivate the unoccupied Pb2+ defects in perovskite films and promote the continuous growth of perovskites. An organic iodide, thiophene-2-ethylammonium iodide (TEAI), is doped in the transport layer to inhibit the halide ion migration and enhance the stability of perovskites synergistically. Self-powered photodetectors are constructed with improved stability, maintaining ≈90% of their initial photocurrents after being stored for ≈87 days in a humid atmosphere with 60% relative humidity. The optimized photodetectors show a high detectivity of 8.1×1012 Jones at 680 nm wavelength, wide linear dynamic range of 121.9 dB, and fast response with a rise/fall time of 1.92/1.17µs. A reflection-mode perovskite photoplethysmography testing system is developed, achieving high heart rate testing capabilities. This work suggests the great potential of perovskite photodetectors for noninvasive medical monitoring applications.

Homogenizing Nucleation and Growth of Tin Perovskite by Polarity-Free Trithiane Coordination Molecule for Efficient and Stable Photovoltaics.

Tin (Sn)-based perovskite solar cells (TPSCs) have garnered significant attention recently, with power conversion efficiencies (PCEs) approaching 16%. Nevertheless, for Sn-based perovskites, their rapid crystallization and easy Sn2+ oxidation are always annoying for fabricating efficient and stable TPSCs. Coordination engineering has been developed for retarding the crystallization rate and Sn2+ passivation, but the homogeneous crystallization of Sn-based perovskites is still challenging due to the asymmetric and polar nature of currently used ligands. Here, a polarity-free S-containing symmetric molecule, 1,3,5-trithiane (TT), is developed to regulate the crystallization of FASnI3. Nonpolar TT with three symmetric S atoms shows equally strong coordination with Sn2+, which enhances the environment stability of the precursor and promotes the homogeneous nucleation and retarded growth of FASnI3 crystals. Consequently, TT-based TPSCs exhibit an improved PCE from 9.02% to 12.87% with robust stability. This study highlights the critical role of ligand polarity in controlling the crystallization behavior of efficient TPSCs.

Durable all-inorganic perovskite tandem photovoltaics.

All-inorganic perovskites prepared by substituting the organic cations (for example, methylammonium and formamidinium) with inorganic cations (for example, Cs+) are effective concepts to enhance the long-term photostability and thermal stability of perovskite solar cells (PSCs)1,2. Hence, inorganic perovskite tandem solar cells (IPTSCs) are promising candidates for breaking the efficiency bottleneck and addressing the stability issue, too3,4. However, challenges remain in fabricating two-terminal (2T) IPTSCs due to the inferior film formation and deep trap states induced by tin cations5-7. Here a ligand evolution (LE) strategy with p-toluenesulfonyl hydrazide (PTSH) is used to regulate film formation and eliminate deep traps in inorganic narrow-bandgap (NBG) perovskites, enabling the successful development of 2T IPTSCs. Accordingly, the 1.31 eV CsPb0.4Sn0.6I3:LE device delivers a record efficiency of 17.41%. Combined with the 1.92 eV CsPbI2Br top cell, 2T IPTSCs exhibit a champion efficiency of 22.57% (certified, 21.92%). Moreover, IPTSCs are engineered to deliver remarkable durability under maximum power point (MPP) tracking, maintaining 80% of their initial efficiency at 65 °C for 1,510 h and at 85 °C for 800 h. We elucidate that LE deliberately leverages multiple roles for inorganic NBG perovskite growth and anticipate that our study provides an insightful guideline for developing high-efficiency and stable IPTSCs.

1D-phase-induced porous templates for efficient two-step-processed mixed-halide perovskite solar cells

The two-step deposition method for preparing mixed-halide perovskite films is advantageous over the common one-step antisolvent method due to its higher controllability and repeatability. However, a key challenge in the two-step process is to create a porous lead-halide template, which promotes the complete conversion into mixed-halide perovskite thin film. Herein, we propose a dimensional engineering strategy to achieve porous lead-halide templates by introducing N,N-diisopropylbenzimidazolium bis(trifluoromethanesulfonyl)imide (IPR-TFSI) in the first step of template formation. First, the IPR+ cation induces the preferential growth of 1D phase perovskites, causing more voids in lead halide. Second, the TFSI- anion passivates the uncoordinated Pb2+ defects and reduce the non-radiative recombination loss in the mixed-halide perovskite thin film. As a result, the mixed-halide perovskite solar cells with a bandgap of 1.65 eV achieve a power conversion efficiency (PCE) up to 21.38 %. Additionally, these solar cells have shown improved thermal stability, retaining over 85 % of their initial PCE after being continuously heated at 85 °C for 1000 h.

Vertically Oriented 2D Perovskite Layer with n = 1 Phase Enables Efficient and Stable Inverted Perovskite Solar Cells.

Surface passivation with 2D perovskites has been reported to be important for high-performance perovskite solar cells (PSCs). However, it is challenging to achieve a controlled growth of 2D perovskites, which typically feature random orientation and various n number. In this paper, we fabricate a 2D layer with a highly ordered orientation and pure n = 1 phase on top of the perovskite film using the organic spacer molecule 7-fluoro-1,2,3,4-tetrahydroisoquinolinehydrochloride (7-FTH). The formed 2D perovskites feature a highly ordered orientation normal to the substrate and a pure n = 1 phase, which efficiently passivates surface defects of the as-prepared perovskite films and improves the energy level alignment between the perovskite film and electron transport layer. Consequently, the modified PSCs achieve a champion power conversion efficiency (PCE) of 24.65% with improved VOC and fill factor. After being stored in an N2 glovebox for 1200 h and kept in ambient air (room temperature and relative humidity of 50-70%) for 840 h, the modified devices retain 93% and 95% of its initial PCE, respectively.

Performance Enhancement of Hole Transport Layer-Free Carbon-Based CsPbIBr2 Solar Cells through the Application of Perovskite Quantum Dots.

CsPbIBr2, with its suitable bandgap, shows great potential as the top cell in tandem solar cells. Nonetheless, its further development is hindered by a high defect density, severe carrier recombination, and poor stability. In this study, CsPbI1.5Br1.5 quantum dots were utilized as an additive in the ethyl acetate anti-solvent, while a layer of CsPbBr3 QDs was introduced between the ETL and the CsPbIBr2 light-harvester film. The combined effect of these two QDs enhanced the nucleation, crystallization, and growth of CsPbIBr2 perovskite, yielding high-quality films characterized by an enlarged crystal size, reduced grain boundaries, and smooth surfaces. And a wider absorption range and better energy band alignment were achieved owing to the nano-size effect of QDs. These improvements led to a decreased defect density and the suppression of non-radiative recombination. Additionally, the presence of long-chain organic molecules in the QD solution promoted the formation of a hydrophobic surface, significantly enhancing the long-term stability of CsPbIBr2 PSCs. Consequently, the devices achieved a PCE of 9.20% and maintained an initial efficiency of 85% after 60 days of storage in air. Thus, this strategy proves to be an effective approach for the preparation of efficient and stable CsPbIBr2 PSCs.

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.

Coherence Programming for Efficient Linearly Polarized Perovskite Light-Emitting Diodes.

Although quasi-two-dimensional (quasi-2D) perovskites are ideal material platforms for highly efficient linearly polarized electroluminescence owing to their anisotropic crystal structures, so far, there has been no practical implementation of these materials for the demonstration of linearly polarized perovskite light-emitting diodes (LP-PeLEDs). This scarcity is due to difficulty in orientation and phase distribution control of the quasi-2D perovskites while minimizing the defects, all of which are required to manifest aligned transition dipole moments (TDMs). To achieve this multifaceted goal, herein, we introduce a synergistic strategy to quasi-2D perovskites by incorporating both a trimethylolpropane triacrylate anchoring layer and 18-Crown-6 molecular passivator into the film fabrication process. It is found that the interfacial anchoring layer guides the oriented growth of perovskites along the (110) plane, whereas the molecular passivator reduces the number of defects and homogenizes the crystal phase. As a result, a quasi-2D perovskite film with macroscopically aligned TDM that renders high radiative recombination and the degree of linear polarization (DoLP) is constructed. This "coherence-programmed emission layer" demonstrates highly efficient LP-PeLEDs, not only achieving a maximum external quantum efficiency of ∼23.7%, a brightness of ∼36,142 cd/m2, and a DoLP of ∼38%, but also significantly improving the signal-to-interference-and-noise ratio in a multi-cell visible light communication system.

Regulating the Grain-Growth Surface for Efficient Near-Infrared Perovskite Light-Emitting Diodes.

Metal halide perovskites hold great potential for next-generation light-emitting diodes (PeLEDs). Despite significant progress, achieving high-performance PeLEDs hinges on optimizing the interface between the perovskite crystal film and the charge transport layers, especially the buried interface, which serves as the starting point for perovskite growth. Here, we develop a bottom-up perovskite film modulation strategy using formamidine acetate (FAAc) to enhance the buried interface. This multifaceted approach facilitates the vertical-oriented growth of high-quality perovskites with minimized defects. Meanwhile, the in situ deprotonation between FA+ and ZnO could eliminate the hydroxyl (-OH) defects and modulate the energy level of ZnO. The resulting FAPbI3-PeLED exhibits a champion EQE of 23.84% with enhanced operational stability and suppressed EQE roll-off. This strategy is also successfully extended to other mixed-halide PeLEDs (e.g., Cs0.17FA0.83Pb(I0.75Br0.25)3), demonstrating its versatility as an efficient and straightforward method for enhancing the PeLEDs' performance.

Effect of lanthanum doped SnO2 on the performance of mixed-cation mixed-halide perovskite layer

Perovskite solar cells (PSCs) have attracted significant attention due to their higher efficiencies and lower fabrication costs. But for the better performance of PSCs, a high-quality electron transport layer (ETL) is crucial. Various ETLs have been employed and among them Tin (IV) oxide (SnO2) has emerged as a promising candidate for electron selective layer in PSCs due to its superior optical and electrical characteristics. However, there is still improvement needed in terms of poor surface morphology and conductivities of SnO2. When SnO2 is used in conjunction with absorber layer in ambient conditions, stability, and charge carrier recombinations at SnO2/perovskite interface remains a serious challenge as well. This study presents the doping of lanthanum (La III), a rare earth element, into SnO2 ETLs to improve the quality and performance of the perovskite layer deposited on top of ETL in ambient condition. With the optimized 4% La (III) doping, SnO2 ETLs become more crystalline with lower parasitic light absorption and surface morphology improves significantly. The improvement in morphology due to doping facilitates larger crystal growth of perovskite in ambient environment. Moreover, Photoluminescence reveals that with optimized level of doping, interfacial charge recombinations are significantly mitigated ensuring smooth injection of electrons into ETL because of superior perovskite film quality. The mixed-cation mixed-halide perovskite film deposited on 4% La:SnO2 ETL show better resistance towards moisture ingress and will substantially contribute to develop long-life of planar PSCs.

Supersaturation- and external force-engineered high-quality 2D CsCu2I3 single-crystalline film for heterogeneous integration in photodetectors

Heterogeneous integration of various crystalline materials in electronic and optoelectronic devices have fueled the development of two-dimensional (2D) perovskite single-crystalline (SC) film. However, it is still challenging to synthesize 2D CsCu2I3 SC film due to the uncontrolled nuclei/growth. In the work, the bottleneck for the synthesis of 2D CsCu2I3 SC film can be well tackled by the solution supersaturation and external pressure for the first time, meanwhile, the morphological transformation of CsCu2I3 from dendritic crystal to 2D film are firstly achieved through controlling nucleation driving force. The heterogeneous integration of 2D CsCu2I3 SCs film on various substrates was demonstrated, a self-powered GaN-CsCu2I3 SC film photodetector exhibits high rectification ratio of 1250 (±1 V) with improved responsivity of 460 mA W−1 and EQE of 163 %, which outperforms most reported 2D lead-free halide perovskite film photodetectors. Furthermore, theoretical computational calculation was employed to investigate their crystal structure and electronic distribution, evidencing that 2D CsCu2I3 SC film could facilitate the separation of photo-induced carriers. The study not only shows an in-depth mechanism for perovskite growth, but also advances the development of 2D copper-based perovskite film and hetero-integration, laying the groundwork for future commercial optoelectronics.

Dual-Functional group passivation to foster buried interface Cohesion for High-Performance perovskite photovoltaics

Despite receiving comparatively less attention, the bottom interface holds a vital role in both charge transfer and the stability of perovskite solar cells (PSCs). Herein, a novel approach involves the incorporation of the natural amino acid D-Methionine (D.M) into the bottom interface, aiming to enhance device performance by serving as a versatile interfacial bridge. The carboxyl group present in D.M serves to suppress surface defects such as oxygen vacancies, thereby significantly improving the optoelectronic properties of SnO2. Additionally, D.M has been found to promote the perovskite crystals growth, leading larger grains size and high-quality films, consequently lowering the defect density. As a result, PSCs demonstrate a notable improvement in open circuit voltage, fill factor and the short circuit current density, ultimately resulting to an enhanced power conversion efficiency from 22.7% to 25.39%. Moreover, the stability of D.M−modified devices is significantly enhanced, as evidenced by the retention of 95% of their initial PCE compared to 76% for the control devices.

Vapor Growth of All-Inorganic 2D Ruddlesden-Popper Lead- and Tin-Based Perovskites.

The 2D Ruddlesden-Popper (RP) perovskites Cs2PbI2Cl2 (Pb-based, n = 1) and Cs2SnI2Cl2 (Sn-based, n = 1) stand out as unique and rare instances of entirely inorganic constituents within the more expansive category of organic/inorganic 2D perovskites. These materials have recently garnered significant attention for their strong UV-light responsiveness, exceptional thermal stability, and theoretically predicted ultrahigh carrier mobility. In this study, we synthesized Pb and Sn-based n = 1 2D RP perovskite films covering millimeter-scale areas for the first time, utilizing a one-step chemical vapor deposition (CVD) method under atmospheric conditions. These films feature perovskite layers oriented horizontally relative to the substrate. Multilayered Cs3Pb2I3Cl4 (Pb-based, n = 2) and Cs3Sn2I3Cl4 (Sn-based, n = 2) films were also obtained for the first time, and their crystallographic structures were refined by combining X-ray diffraction (XRD) and density functional theory (DFT) calculations. DFT calculations and experimental optical spectroscopy support band-gap energy shifts related to the perovskite layer thickness. We demonstrate bias-free photodetectors using the Sn-based, n = 1 perovskite with reproducible photocurrent and a fast 84 ms response time. The present work not only demonstrates the growth of high-quality all-inorganic multilayered 2D perovskites via the CVD method but also suggests their potential as promising candidates for future optoelectronic applications.