Perovskite Precursor Research Articles

Optical enhancement in perovskite thin films using moth-eye anti-reflection film

Perovskite solar cells represent an emerging photovoltaic technology. With the latest record efficiencies exceeding 25% coupled with low fabrication cost and tunable transparency, perovskite solar cells demonstrate promising applications as solar windows. For these applications, the perovskite solar cells need to be semi-transparent to allow incident light to pass through the windows while generating electricity. However, semi-transparency compromises light absorption in the solar cells. In this work, optical enhancement in perovskite thin films using moth-eye anti-reflection (AR) film is investigated. Perovskite thin films with different thicknesses are used and the thickness is controlled by varying the spin speeds during the deposition of the perovskite precursor. The optical effects in the perovskite films without and with moth-eye AR film are studied. From the findings, the reflection loss is reduced by maximum of ∼4%, which contributes to a higher light absorption in the perovskite layer, due to the AR effect of the moth-eye structure. These results imply that the moth-eye film can be a promising and facile alternative for developing a highly efficient and semi-transparent perovskite solar cell with a thin absorber layer.

Crystallization Enhancement and Ionic Defect Passivation in Wide‐Bandgap Perovskite for Efficient and Stable All‐Perovskite Tandem Solar Cells

AbstractBy integrating wide‐bandgap (WBG) and narrow‐bandgap perovskites, monolithic all‐perovskite tandem solar cells have garnered significant attention as a prospective strategy for surpassing the efficiency limits of single‐junction cells. However, the WBG subcells, which significantly impact the performance and operational stability of all‐perovskite tandem solar cells, face notable challenges associated with pronounced nonradiative recombination losses and limited film photostability. Here, an efficient method is reported by adding potassium hypophosphite into the perovskite precursor solution to simultaneously regulate crystallization and passivate ionic defects in WBG perovskites. This approach results in high‐quality perovskite films and significantly improves the performance and photostability of WBG perovskite solar cells. The single‐junction devices with a 1.79 eV bandgap achieve a champion power conversion efficiency (PCE) of 20.06% with an open‐circuit voltage of 1.32 V. The devices retain ≈96% of their initial PCE following 913 h of continuous AM 1.5 G illumination. With these WBG perovskite subcells, monolithic all‐perovskite tandem solar cells are fabricated with an efficiency of 26.08%.

Mechanism of defect passivation achieved by chemical interaction in inverted perovskite solar cells

A variety of defects exist in the solution-processed polycrystalline perovskites, resulting in photovoltaic output losses and degradation. Chemical interaction is a promising way to realize the passivation of defects. Herein, cetyl pyridinium bromide (CPB) containing both pyridine units and long-chain alkyl groups was introduced in the perovskite precursor solution as a passivation agent. Experimental results show that pyridine unit in CPB formed coordination with uncoordinated Pb2+, which also interact with N–H in MAPbI3. Meanwhile, long-chain alkyl groups in CPB had interaction with MAI and PbI2 in MAPbI3. Thus, trace amount of CPB in the precursor solution improved the optoelectronic properties of perovskite films and suppressed non-radiative carrier recombination in perovskite solar cell (PSC). CPB-modified perovskite films exhibit a lower trap-state density and stronger carrier migration capability. It enables the significant enhancement of PCE values of the p-i-n structured PSC from 18.27 % to 20.53 %, accompanied by the improved stability. Our work exhibits more possibility between passivating additive and PSC performance.

Effective of l-tyrosine hydrochloride on the photovoltaic performance of tin-based perovskite solar cells by suppressing tin (II) oxidation

Additive engineering has been widely concerned to improve the photovoltaic performance of tin-based perovskite solar cells (PSCs). Here, the tin-based perovskite precursor solution is modified with L-Tyrosine hydrochloride (LTHCl). The results demonstrate that the defect state density of tin-based perovskite films is reduced by improving their morphology and crystallinity. The electrical properties of tin-based perovskite film are enhanced by suppressing the Sn2+ oxidation. As a result, the open-circuit voltage of tin-based PSCs is increased from 0.53 V to 0.59 V. The best power conversion efficiency of the tin-based PSC with LTHCl is up to 8.63 %, which is higher than that of the pristine device (7.65 %). Meanwhile, the tin-based PSC with LTHCl retains 84 % of its initial efficiency after over 1140 h in a nitrogen glove box.

Tailoring Crystallization Dynamics of CsPbI3 for Scalable Production of Efficient Inorganic Perovskite Solar Cells

AbstractAll‐inorganic perovskite cesium lead triiodide (CsPbI3) with inorganic nature, low‐temperature synthesis, and a suitable bandgap is desirable for high‐performance photovoltaics. However, the scalable production of CsPbI3 photovoltaics is still challenging due to a large nucleation energy barrier and slow phase transition during unassisted natural crystallization. Here, the crystallization dynamics of CsPbI3 thin films is tailored via lead acetate (PbAc2) substitution in the perovskite precursor ink, allowing the scalable fabrication of efficient all‐inorganic perovskite solar cells and minimodules. Introducing PbAc2 enlarges CsPbI3 colloid size in the precursor and reduces the nucleation energy barrier. Additionally, reactions between acetate and dimethylammonium in the wet film accelerate the removal of dimethylammonium additives and generate solvent vapors for self‐regulate internal solvent annealing, resulting in densely packed, uniform, and pinhole‐free CsPbI3 perovskite films over large areas. This strategy demonstrates inverted CsPbI3 solar cells with 20.17% efficiency and good operational stability (retaining 95.5% of initial efficiency after continuous operation for 1800 h) and 15.1%‐efficient CsPbI3 minimodules with an active area of 26.8 cm2.

Surface modification of paper substrates by a printed UV curing varnish layer and a transferred transparent PEDOT:PSS electrode for paper-based perovskite light-emitting devices in ambient air

Paper, a low-cost and eco-friendly substrate, can be used to prepare flexible electronic devices by resorting to surface modification technology. In this study, we investigated the surface modification of paper substrates, including those that were uncoated or coated with traditional mineral coatings, to analyze the enhancements to surface flatness and water resistance using a UV curing varnish layer. Furthermore, we explored the formation of perovskite films on the surface-modified paper substrates utilizing a PEO-doped perovskite precursor solution in ambient air, and the surface morphology, crystallinity, photoluminescence properties, and absorption properties of the prepared perovskite films were discussed accordingly. Considering the nontransparent feature of paper-based substrates, the inverted perovskite light-emitting device was finally assembled by transfer printing a transparent PEDOT:PSS layer as a top electrode. The conductive and optical properties of the electrode layer were thus analyzed as well. It is found that the surface modification of paper substrates via printing the UV curing varnish can illustrate significant improvements, such as pore-filling on the surface, a more than 10-fold reduction in roughness, and downward penetration. Moreover, prepared perovskite films on the surface-modified coated paper exhibit superior enhancements, including photoluminescence, higher crystallinity, and surface roughness and porosity. Devices fabricated on the surface-modified substrates are less susceptible to short-circuiting. The electroluminescence on the surface-modified coated paper substrate is 2.16 times higher than the prepared device on the surface-modified base paper substrate and even 3.23 times higher than on the PET substrate. Therefore, it is quite feasible to fabricate a perovskite light-emitting device on the modified surface of a paper substrate by using a printed UV curing varnish layer, which is expected to be a promising coating to polish the paper surface in the preparation of electroluminescent devices.

Anion-π interactions suppress phase impurities in FAPbI3 solar cells.

Achieving both high efficiency and long-term stability is the key to the commercialization of perovskite solar cells (PSCs)1,2. However, the diversity of perovskite (ABX3) compositions and phases makes it challenging to fabricate high-quality films3-5. Perovskite formation relies on the reaction between AX and BX2, whereas most conventional methods for film-growth regulation are based solely on the interaction with the BX2 component. Herein, we demonstrate an alternative approach to modulate reaction kinetics by anion-π interaction between AX and hexafluorobenzene (HFB). Notably, these two approaches are independent but work together to establish 'dual-site regulation', which achieves a delicate control over the reaction between AX and BX2 without unwanted intermediates. The resultant formamidinium lead halides (FAPbI3) films exhibit fewer defects, redshifted absorption and high phase purity without detectable nanoscale δ phase. Consequently, we achieved PSCs with power conversion efficiency (PCE) up to 26.07% for a 0.08-cm2 device (25.8% certified) and 24.63% for a 1-cm2 device. The device also kept 94% of its initial PCE after maximum power point (MPP) tracking for 1,258 h under full-spectrum AM 1.5 G sunlight at 50 ± 5 °C. This method expands the range of chemical interactions that occur in perovskite precursors by exploring anion-π interactions and highlights the importance of the AX component as a new and effective working site to improved photovoltaic devices with high quality and phase purity.

Symmetrical dicyano-based imidazole molecule-assisted crystallization and defects passivation for high-performance perovskite solar cells

Benefiting from the simple and low-cost fabrication of the one-step anti-solvent spin-coating process, the perovskite solar cells (PSCs) have a boost development. However, a great number of defects are generated during solution-fabrication process, retarding the development of PSCs seriously. In this study, the utilization of 4,5-dicyanoimidazole (DCI) as an additive for perovskite precursor solution was investigated. The presence of the double –CN groups in DCI facilitated the formation of Lewis acid-base coordination with unsaturated Pb2+ ions, as well as interaction with I- anions by the –NH- moiety, resulting in the enhanced perovskite film crystallinity, the reduced grain boundaries, and a significant reduction in the defects density of the perovskite film. The decreased trap-assisted recombination and voltage open circuit (VOC) losses in the PSC resulted in the improved photovoltaic performance of device treated by DCI molecule, the PCE increased from 19.59 % to 21.87 % significantly. Moreover, the unencapsulated device with DCI additive exhibited a remarkable 87.8 % retention of its initial PCE after exposure under 10–20 % relative humidity for 60 days, demonstrating an excellent stability than control device.

Disperse PbI2 clusters with 4-Difluoromethyl-Benzylamine Hydrochloride to improve the efficiency and stability of perovskite solar cells

Generally, an excess of PbI2 is used in the perovskite precursor solution to increase the crystallinity of the perovskite. However, excessive PbI2 will form PbI2 clusters during the annealing process of the perovskite film, which will cause the decomposition of perovskite solar cells (PSCs) and affect the stability of the device. Here we use 4-Difluoromethyl-Benzylamine Hydrochloride (4F2M-BACl) to do interfacial doping of the perovskite film to passivate the defects on the surface of the perovskite film and disperse the PbI2 clusters through the interaction with PbI2. Under the passivation effect of 4F2M-BACl, the power conversion efficiency (PCE) of PSCs was increased from 18.51% to 21.51%, and the hysteresis indicator (HI) was lower. In addition, the hydrophobic functional group F and benzene ring of 4F2M-BACl and the dispersing effect of 4F2M-BACl on PbI2 have significantly improved the stability of the device. Unencapsulated devices with 4F2M-BACl modification were able to maintain over 85% of the initial PCE after 170 h at 80% relative humidity (RH).

Break through the Steric Hindrance of Ionic Liquids with Carbon Quantum Dots to Achieve Efficient and Stable Perovskite Solar Cells.

Overcoming the negative impact of residual ionic liquids (ILs) on perovskite films based on an in-depth understanding of chemical interactions between ionic liquids and preparing perovskite precursor solutions is a great challenge when aiming to simultaneously achieve long-term stability and high efficiency within IL-based perovskite solar cells (PSCs). Herein, 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), a type of IL, was introduced into the perovskite precursor solution, and carbon quantum dots (CQDs) were further introduced into the antisolvent to enhance the photovoltaic properties of PSCs. Both ILs and CQDs synergistically manipulate the crystallization process and passivate defects to obtain high-quality perovskite films. Besides serving as passivation sites to strengthen the collaboration between additives and perovskite materials, the cointroduction of CQDs further promotes the carrier transport process since it not only provides carrier channels at grain boundaries but also forms better energy alignment, which effectively overcomes the charge transfer loss caused by the steric hindrance of ILs. Based on such a synergistic effect of ILs and CQDs, the n-i-p MAPbI3-based PSCs achieve the highest efficiency of 20.84% with improved stability. This simple and low-cost synergistic integration method will subsequently provide direction for optimizing ILs to improve the photovoltaic performance of PSCs.

Systematic in situ Investigation of the Formation of NH3 Cracking Catalysts from Precursor Perovskites ABO3 (A=La,Ca,Sr and B=Fe,Co,Ni) and their Catalytic Performance

AbstractThis work addresses the formation of ammonia (NH3) decomposition catalysts derived from perovskites ABO3 (A=La, Ca, Sr, and B=Fe, Co, Ni) precursors via operando synchrotron X‐ray diffraction experiments. During the reaction in NH3, the perovskite precursors are decomposed and the transition metals are reduced. Depending on their reduction properties, active metallic catalysts are formed in situ on La2O3 as support. The reduction behavior of the perovskites, formation of intermediate phases during activation, and catalytic performance was studied in detail. In addition, microstructure properties such as crystallite sizes and particle morphology were analyzed. Co‐/Ni‐based perovskites decomposed completely during activation to Co0/Ni0 supported on La2O3 while Fe‐based perovskites were fully stable but inactive in catalysis. This difference is due to varying electronic properties of the transition metals, e. g., decreasing electronegativity from Ni to Fe. With decreasing reducibility, the intermediate phases during activation formed more distinct. La3+ was partially substituted by Ca2+/Sr2+ in LaCoO3 to test for advantageous effects in NH3 decomposition. The best performance was observed using the precatalyst La0.8Sr0.2CoO3 with a conversion of 86 % (100 % NH3, 15000 mL g−1 h−1) at 550 °C.

Crystallization Retardation and Synergistic Trap Passivation in Perovskite Solar Cells Incorporated with Magnesium-Decorated Graphene Quantum Dots.

One of the encouraging strategies for enhancing the efficiency of perovskite solar cells (PSCs) is to reduce defects, trap states of pinholes, and charge recombination rate in the light absorber layer of perovskite, which can be addressed by increasing the perovskite grain size. The utilization of Mg-decorated graphene quantum dots (MGQD) or graphene quantum dots (GQDs) into a perovskite precursor solution for further crystal modification is introduced in this study. Studies on the crystalline structure and morphology of MGQD generated from GQDs demonstrate that MGQD has a greater crystal size than GQD. Therefore, higher light absorption in the whole UV-vis spectrum and a larger grain size for the perovskite/MGQD layer compared to the perovskite/GQD sample are achieved. Moreover, more photoluminescence peak quenching of perovskite/MGQD and extended carrier recombination lifetime (from 3 to 40 ns) verify the surface and grain boundary trap passivation compared to pristine perovskite. Consequently, PSCs in an n-i-p configuration containing perovskite/MGQD show a higher performance of 10.2% in comparison to the pristine perovskite at 7.2%, attributed to the enhanced JSC from 13.2 to 19.1 mA cm-2. Thus, incorporating MGQDs into the perovskite layer is a hopeful approach for obtaining a superior perovskite film with impressive charge extraction and decreased nonradiative charge recombination.

Buried interface modified by guanidinium iodide for enhanced efficiency and stability of perovskite solar cells

A guanidinium iodide layer is deposited on SnO2 to modify the buried interface of SnO2/CH3NH3PbI3 in perovskite solar cells. It is found that hydrogen bonds are formed between GAI and SnO2, which not only reduce the defects of SnO2 but also anchor the GAI molecules on the surface of SnO2 and then functioned as nucleation sites to form a 2D perovskite layer at the SnO2/CH3NH3PbI3 interface. Moreover, GAI molecules are demonstrated to distribute at the grain boundaries in the whole perovskite film, and hydrogen bonds are formed between GAI and perovskite. These hydrogen bonds effectively suppress the charge trapping and recombination regions induced by the under-coordinated iodine species. A CH3NH3Cl additive is found to be essential in the perovskite precursor, which manipulates the crystal growth dynamic and the vertical crystallization and hence the improved morphology of the perovskite films. Dramatically increased efficiency and stability are demonstrated in the perovskite solar cells. The optimized device shows a more than 20% higher PCE than the reference device. Besides, the device also remains 80% of its initial efficiency after storage for 60 days, suggesting the robust of this device.

Inhibition of Sn2+ Oxidation in FASnI3 Perovskite Precursor Solution and Enhanced Stability of Perovskite Solar Cells by Reductive Additive.

Tin-based halide perovskite solar cells (Sn-PSCs) have attracted a progressive amount of attention as a potential alternative to lead-based PSCs (Pb-PSCs). Sn-perovskite films are fabricated by a solution process spin-coating technique. However, the efficiency of these devices varies significantly with the different batches of precursor solution due to the poor chemical stability of SnI2-DMSO and the oxidation of Sn2+ to Sn4+. This study investigated the origin of Sn2+ oxidation before film formation, and it was identified that the ionization of SnI2 in dimethyl sulfoxide (DMSO) causes the oxidation of free Sn2+ and I- ions. To address these issues, this study introduces the reductive additive 4-fluorophenylhydrazine hydrochloride (4F-PHCl) in the FASnI3 perovskite precursor solution. The hydrazine functional (-NH-NH2) group converted detrimental Sn4+ and I2 defects back to Sn2+ and I- in precursor solution while retaining the properties of the perovskite solution. Furthermore, the addition of 4F-PHCl in the precursor solution effectively slows the crystallization process, enhancing the crystallinity of FASnI3 perovskite films and guaranteeing the Sn2+/I- stoichiometric ratio, ultimately leading to a power conversion efficiency (PCE) of 10.86%. The hydrophobic fluorinated benzene ring in 4F-PHCl ensures moisture stability in perovskite films, allowing unencapsulated PSCs to retain over 92% of their initial PCE in an N2-filled glovebox for 130 days. Moreover, the 4F-PHCl-modified encapsulated PSCs showed superior operational stability for 420 h and maintained 95% of their initial PCE for 300 h under maximum power point tracking at 1 sun continuous illumination. This study's findings provide a promising pathway to create a controlled Sn-based perovskite precursor solution for highly reproducible and stable Pb-free Sn-PSCs.

High-Performance Indoor Perovskite Solar Cells by Self-Suppression of Intrinsic Defects via a Facile Solvent-Engineering Strategy.

Lead halide perovskite solar cells have been emerging as very promising candidates for applications in indoor photovoltaics. To maximize their indoor performance, it is of critical importance to suppress intrinsic defects of the perovskite active layer. Herein, a facile solvent-engineering strategy is developed for effective suppression of both surface and bulk defects in lead halide perovskite indoor solar cells, leading to a high efficiency of 35.99% under the indoor illumination of 1000 lux Cool-white light-emitting diodes. Replacing dimethylformamide (DMF) with N-methyl-2-pyrrolidone (NMP) in the perovskite precursor solvent significantly passivates the intrinsic defects within the thus-prepared perovskite films, prolongs the charge carrier lifetimes and reduces non-radiative charge recombination of the devices. Compared to the DMF, the much higher interaction energy between NMP and formamidinium iodide/lead halide contributes to the markedly improved quality of the perovskite thin films with reduced interfacial halide deficiency and non-radiative charge recombination, which in turn enhances the device performance. This work paves the way for developing efficient indoor perovskite solar cells for the increasing demand for power supplies of Internet-of-Things devices.

Mutually Tuned Dual Additive Engineering Synergistically Enhances the Photovoltaic Performance of Tin-Based Perovskite Solar Cells.

Tin-based perovskite solar cells (T-PSCs) have become the star photovoltaic products in recent years due to their low environmental toxicity and superior photovoltaic performance. However, the easy oxidation of Sn2+ and the energy level mismatch between the perovskite film and charge transport layer limit its efficiency. In order to regulate the microstructure and photoelectric properties of tin-based perovskite films to enhance the efficiency and stability of T-PSCs, guanidinium bromide (GABr) and organic Lewis-based additive methylamine cyanate (MAOCN) are introduced into the FA0.9PEA0.1SnI3-based perovskite precursor. A series of characterizations show that the interactions between additive molecules and perovskite mutually reconcile to improve the photovoltaic performance of T-PSCs. The introduction of GABr can adjust the band gap of the perovskite film and energy level alignment of T-PSCs. They significantly increase the open-circuit voltage (Voc). The MAOCN material can form hydrogen bonds with SnI2 in the precursor, which can inhibit the oxidation of Sn2+ and significantly improve the short-circuit current density (Jsc). The synergistic modulation of the dual additives reduces the trap-state density and improves photovoltaic performance, resulting in an increased champion efficiency of 9.34 for 5.22% of the control PSCs. The unencapsulated T-PSCs with GABr and MAOCN dual additives prepared in the optimized process can retain more than 110% of their initial efficiency after aging for 1750 h in a nitrogen glovebox, but the control PSCs maintain only 50% of their initial efficiency kept in the same conditions. This work provides a new perspective to further improve the efficiency and stability of T-PSCs.

High‐Speed Deposition of Large‐Area Narrow‐Bandgap Perovskite Films for All‐Perovskite Tandem Solar Mini‐Modules

AbstractDeveloping all‐perovskite tandem solar cells is an effective approach to extend the limit of power conversion efficiency. However, fast preparation of large‐area and high‐quality narrow‐bandgap Sn‐based perovskite films still remains a major challenge in fabricating all‐perovskite tandem modules. Here high‐crystalline and compact narrow‐bandgap perovskite films with an area over 100 cm2 are well prepared by combining compositional, solvent and additive engineering. The use of 2‐methoxyethanol as a solvent enables the fast deposition of narrow‐bandgap perovskite films. Adding proper amounts of dimethyl sulfoxide and surfactant L‐α‐phosphatidylcholine into the narrow‐bandgap perovskite precursor effectively enhances the crystallinity and coverage of the resulting perovskite films, respectively. Based on these studies, narrow‐bandgap perovskite and all‐perovskite tandem mini‐modules with an aperture area of 10.4 cm2 are constructed and exhibit high efficiencies of 13.2% and 16.4%, respectively. This study provides an option for fast deposition of high‐quality narrow‐bandgap perovskite films, which is beneficial for the scalable production of all‐perovskite tandem solar modules.

Benzophenone: A Small Molecule Additive for Enhanced Performance and Stability of Inverted Perovskite Solar Cells.

In this study, we investigated the impact of benzophenone (BP), a small molecule additive, on the performance and stability of inverted perovskite solar cells (PSCs). Specifically, we introduced BP into the perovskite precursor solution of FAPbI3 to fabricate PSCs with an ITO/PEDOT:PSS/BP:FAPbI3/PCBM/C60/PCB/Ag architecture. The incorporation of BP with an optimum concentration of 2 mg mL-1 significantly enhanced the power conversion efficiency (PCE) of the inverted PSC from 13.12 to 18.84% with negligible hysteresis. Notably, the BP-based PSCs retained ∼90% of their initial PCE after being stored in ambient air with 30% relative humidity at 25 °C for 700 h. In contrast, control devices showed rapid degradation, retaining only 30% of their initial value within 300 h under the same conditions. We attributed the superior performance and stability of the BP-based PSCs to the grain boundary passivation of the perovskite film. The improvement was mainly attributed to the intermolecular interaction between the O-donor Lewis base BP material and both Pb2+ and FA+ in FAPbI3. This effectively suppresses trap-assisted recombination and promotes the conversion of the δ-phase to photoactive and stable α-phase FAPbI3. Overall, our findings suggest that BP is a promising additive for improving the performance and stability of inverted PSCs.

Ionic Liquid Additives for Efficient and Durable Two-Step Perovskite Photovoltaic Devices

Ionic liquids (ILs) have found widespread use in controlling the crystallization process of perovskites, optimizing the morphology and enhancing the device performance, especially in the one-step method. However, research regarding the effects of ionic liquids on perovskite devices prepared using the two-step method remains relatively scarce. Here, an IL 1-Hexyl-3-methylimidazolium Tetrafluoroborate (HMIMBF4) is selected as an additive in the perovskite precursor solution for the fabrication of PSCs using the two-step method. Our study involves a systematic exploration of the precise effects of ILs on the morphology of perovskite thin films, defect density, and photovoltaic performance. IL HMIMBF4 is convincingly shown to possess a robust chemical affinity with perovskite components, thereby establishing a basis for the inhibition of ion migration. Concurrently, ILs play a pivotal role in governing the morphology of perovskite while also facilitating the conversion of lead iodide into the perovskite structure. Benefiting from the regulation of the perovskite morphology and defect states by IL HMIMBF4, the devices with an efficiency exceeding 23% is ultimately achieved. Our research provides a comprehensive comprehension and contributes to advancing the utilization of ILs in two-step photovoltaic devices.

Dimension-Controlled Synthesis of Hybrid-Mixed Halide Perovskites for Solar Cell Application.

Despite the rapid improvement of photovoltaic (PV) efficiency in hybrid organic-inorganic metal halide perovskites (HOIPs), the fabrication procedure of a compact thin film in a large-area application is still a tedious work. Apart from the quality of the thin film, the stability of the perovskite materials and the expensive organic hole transport layer (HTL) within the HOIP-based PV device are the major issues that need to be addressed prior to their commercialization. Herein, a unique glass rod-based facile fabrication technique for producing a compact and stable thin film utilizing a mixed-halide-based perovskite precursor solution is demonstrated. The fabricated devices deliver high photoconversion efficiency (PCE) without the use of any HTL and show an excellent stability under ambient conditions. By varying the organic CH3NH3I (MAI) and inorganic PbBr2 content, perovskite materials with different dimensions, i.e., 3D, 2D, and 1D, are synthesized to produce an active layer for PV devices. Although a 2D single-halide perovskite is reported earlier, herein two different mixed-halide 2D perovskites, i.e., MA2PbI2Br2 and MAPb2IBr4, are synthesized successfully, and their performance is compared in detail along with that of 1D and 3D mixed-halide perovskites. The facile synthesized mixed-halide 2D-based MA2PbI2Br2 perovskite shows a PCE of 10.14% with a high stability of 92% after 100 days without encapsulation, which is much superior as compared to that of the mixed-halide 3D MAPbIBr2. The semiconducting behavior as well as the nature of the bandgap of the synthesized compounds is examined by pursuing density functional theory calculations. Specifically, the role of iodine doping to modify the electronic band structure is investigated, and introduction of iodine is found to reduce the effective masses of both electrons and holes in the perovskite material.