This study explores the fabrication of compact‐titanium dioxide (c‐TiO 2 ) electron transport layer capped with mesoporous‐titanium dioxide (m‐TiO 2 ) using spray pyrolysis while controlling layer thickness. X‐ray diffraction confirmed a crystalline rutile c‐TiO 2 structure, with crystallite size increasing from 22 to 24 nm as deposition time increased. Field emission‐scanning electron microscopy showed uniform surface coverage, with average grain size increasing from 195.57 to 242.34 nm, and UV–vis spectra indicated a bandgap near 430 nm. Electrical measurements revealed improved conductivity (3 × 10 6 to 1.18 × 10 7 S/m) and reduced sheet resistance (7.34–6.33 Ω/□). The best conductivity was achieved with a 7 s meso ‐epitaxial TiO 2 layer, enhancing electron transport and charge carrier mobility. Current‐voltage (I–V) characteristics demonstrated enhanced electron transport properties, with increased charge carrier mobility from 1.059 × 10 3 to 2.523 × 10 3 cm 2 V −1 s −1 . Furthermore, electron‐only devices with meso ‐passivated TiO 2 showed a higher trap density (2.148 × 10 15 cm −3 ) but improved mobility (1.857 × 10 3 cm 2 V −1 s −1 ) compared to pristine TiO 2 . These findings highlight the potential of meso ‐epitaxial TiO 2 for enhancing inorganic perovskite solar cells.

Solar steam generation, a technology that harnesses the abundant and clean energy of sunlight, has emerged as a promising solution for global freshwater scarcity. This study explores the potential applications of gold and silver nanostructures coated with tin dioxide and blended to form mixtures to improve photothermal properties for solar steam generation. Transmission electron microscopy was used to successfully confirm the rod-like structures and diverse sizes of the gold and silver nanoparticles, with aspect ratios ranging from 2.2 to 3.3. The collected ultraviolet-visible spectra showed broadened and enhanced light absorption across a range of 350-850 nm. Furthermore, under 1.3511 kW/m2 solar power, solar steam generation efficiencies were found to be 10.87 +/- 0.05, 10.71 +/- 0.06, and 10.32 +/- 0.04% for tin dioxide-based nanofluids, CTAB-based nanofluids, and pure water, respectively. Notably, tin dioxide-based nanofluids also exhibited a higher heat capacity (7734.12 J/degrees C & centerdot;Kg) as compared to the CTAB-based nanofluids (7709.25 J/degrees C & centerdot;Kg) and pure water (4200 J/degrees C & centerdot;Kg), demonstrating its superior thermal management. These results indicate that the strategic blending of tin dioxide encapsulated gold and silver nanorods offers a promising approach to advancing solar energy technologies through improved nanomaterial design.

Organic–inorganic perovskite solar cells suffer from low stability and the solution methods used for fabrication are not always scalable or reproducible. Perovskite solar cells with inorganic absorber layers and charge transport layers are an attractive route towards achieving long-term stability. Additionally, resistive evaporation allows for scalable and reproducible thin films. CsPbBr _3 active layers of varying thicknesses are prepared using the multi-step sequential resistive evaporation of CsBr and PbBr _2 . Charge transport layers of tin oxide and cuprous oxide are prepared using resistive evaporation of the metal followed by thermal oxidation to form a metal oxide. These layers are combined to form an all-inorganic, solvent-free solar cell. The optimal device has a CsPbBr _3 thickness of 775 nm, and has a power conversion efficiency, open circuit voltage, short circuit current density, and fill factor of 3.0 ^2 , and 54

Bulk‐heterojunction organic solar cells have brought much interest in renewable energy due to their low cost and large‐scale fabrication. Their power conversion efficiency (PCE) suffers due to charge recombination, limiting their commercialization. In this study, the plasmonic resonance of colloidal copper nanorods (CuNRs) has been employed to enhance light absorption inside phenyl‐C 60 ‐butyric acid methyl ester: poly(3‐hexylthiophene) (P3HT:PCBM). The CuNRs with a diameter of 24.63 ± 2.1 nm and length of 53.99 ± 0.57 nm induced transverse and longitudinal absorption peaks at 450 and 680 nm, respectively, inside P3HT:PCBM. The peaks intensify with an increase in the concentration of CuNRs. Photoluminescence spectra showed an improved charge carrier lifetime for P3HT:PCBM with the incorporation of CuNRs. The CuNRs have improved the PCE of ITO/PEDOT:PSS/P3HT:PCBM:CuNRs/LiF/Al device by 34.97%. Incorporating CuNRs in P3HT:PCBM has the potential to improve the PCE of the organic solar cell by inducing plasmonic resonance.

Metal-organic frameworks have emerged as promising materials for environmental remediation due to their high surface area, tunable porosity, and structural versatility. However, most reported MOF photocatalysts are synthesized as powders, which are prone to aggregation, and challenging to recover after use. Herein, monolithic cobalt-doped ZIF-8 was synthesized via a rapid sol-gel method for the degradation of tartrazine dye in aqueous solution. PXRD results confirmed the successful formation of the ZIF-8 framework with preservation of the sodalite topology after cobalt incorporation, while UV-Vis DRS revealed the emergence of visible-light absorption bands attributed to d-d transitions of tetrahedrally coordinated Co2+ ions. Tauc analysis indicated the presence of mid-gap electronic states (1.9 eV) associated with cobalt doping, enabling improved visible-light responsiveness. The Co@ZIF-8 monolith achieved 86.0 ± 1.6% degradation under optimal conditions (4 mg L-1, pH 5, 45 mg, 150 min), outperforming pristine ZIF-8 (42.8 ± 2.1%). Dark adsorption control showed 31.9 ± 1.9% removal, confirming dye concentration on the monolith surface prior to photocatalysis. Kinetic studies indicated pseudo-first-order behaviour, while reusability tests showed retained activity after five cycles, with PXRD confirming framework integrity. These findings highlight the potential of monolithic Co-doped ZIF-8 as a stable and reusable photocatalyst for the treatment of dye-contaminated wastewater.

In this work, we demonstrated the preparation of three-dimensional(3D)/two-dimensional(2D)-MASnI3/ PEA2SnI4 Sn-based perovskite heterostructure thin films from Tin (ii) iodide (SnI2), phenethylammonium iodide (PEAI) and methylammonium iodide (MAI) single layers by sequential physical vapor deposition (SPVD) without breaking the vacuum. We optimized the structural, optical, morphological, and electrical properties of the resulting solvent-free synthesized 3D/2D perovskite thin films by controlling the annealing time and PEAI thickness. X-ray diffraction (XRD) diffractograms confirmed the formation of the tetragonal 3D-MASnI3 with a pure phase (n=1) 2D-PEA2SnI4 perovskite protective layer. The morphology and the crystallinity of the films improved with an increase in PEAI thickness and annealing time with the resulting films exhibiting enlarged grains and low surface roughness.The grain growth was attributed to formation of a thin 2D-PEA2SnI4 layer which controlled the rate of MAI diffusion and therefore slowing down the nucleation rate of the 3D-perovskite. Photoluminescence (PL) measurements revealed that 3D/2D perovskite films with 30 nm PEAI and annealed for 40 min exhibit the highest photoluminescence (PL) emission intensity, demonstrating suppression of non-radiative recombination. Space charge limited current (SCLC) method analysis of dark current-voltage (I-V) characteristics revealed a reduction of electron trap density from 3.92 & times; 1016 to 2.56 & times; 1016 cm-3 and an increase in electron mobility from 2.89-9.97 cm-2v-1s-1 as PEAI thickness increased from 0 to 30 nm further confirming the improvement in the film quality. Our study suggests a solvent-free strategy of preparing high quality and reproducible 3D/2D Sn-based perovskite heterostructure thin films by using SPVD without breaking the vacuum.

Copper‐zinc bimetallic nanocomposites (Cu:Zn BMNCs) were synthesized using a wet chemistry and used as an absorber material in thin‐film organic solar cells (TFOSCs). The nanocomposites were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), and photoluminescence (PL). A traditional device architecture ITO/PEDOT:PSS/P3HT:PCBM‐Cu:Zn BMNCs/LiF/Al was used for fabrication. The pristine device, which used a P3HT: PCBM mixture, achieved a PCE of 3.22%. Additionally, adding Cu:Zn BMNCs to the photoactive layer significantly enhanced device performance. The optimal concentration of 1 wt% Cu:Zn BMNCs resulted in a PCE of 5.40%, an increase of over 68% compared to the pristine device. This improvement is attributed to better optical absorption driven by light scattering and localized surface plasmon resonance (LSPR) effects within the absorber layer, which enhances photon harvesting and charge generation. Furthermore, the experiment showed a slight increase in short‐circuit current density ( J sc ), due to improved charge carrier collection efficiency. These results demonstrate that Cu:Zn BMNCs can enhance both the optical absorption and electrical performance of TFOSCs.

Inorganic halide perovskites (HaP) such as CsPbBr3 are promising materials for optoelectronic applications, but their performance is strongly affected by defect states, impurity phases, and limited crystallinity. In this work, we systematically investigate the combined effect of immersion time during a 2-step solution deposition and subsequent surface passivation with phenethylammonium bromide (PEABr) on the structural, morphological, and optical properties of CsPbBr3 HaP thin films. X-ray diffraction reveals that 10 min immersion time yields the highest crystallinity (82.7%) with suppressed CsPb2Br5 (Pb-) and Cs4PbBr6 (Cs-rich) impurity phases, while PEABr passivation further reduces the dislocation density and microstrain without altering the intrinsic orthorhombic crystal structure CsPbBr3 HaP. Scanning electron microscopy conforms that 20-40% PEABr treatment suppress pinholes and enhance film coverage, facilitating compact and smooth morphology synthesis. Optical study of CsPbBr3 HaP thin film shows a direct broadgap of 2.33 eV with reduced Urbach energy for PEABr-treated films, indicating suppressed disorder and trap states. Steady-state photoluminescence intensities remarkably increased with PEABr concentration, demonstrating improved radiative recombination. This work highlights an integrated strategy where optimized immersion with moderate PEABr passivation yields defect-suppressed CsPbBr3 HaP thin films with superior optoelectronic quality, offering practical guidelines for stable inorganic perovskite solar cells.

The urgent need to address fossil fuel challenges has led to a surge in green energy technologies, including solar cells. Nanodimensional particles, particularly 2D nanostructures, have shown great potential in these technologies due to their high surface area-to-volume ratio. Nickel oxide (NiO) is a promising p-type semiconductor for solar cell photo-cathodes, offering remarkable physical and chemical properties at a relatively low cost. However, its surface morphology, area, and pores have a significant impact on performance. Traditional chemical synthesis methods for NiO nanostructures have several drawbacks, including the use of hazardous precursors. To address this, we present for the first time a novel bioengineering method using bamboo shoot extract to produce 2D NiO nanostructures. The results have been supported by Density Functional Theory (DFT) calculations. The DFT calculations revealed that NiO is a p-type semiconductor with direct band gap for spin-down at Г. The results show that the bioengineered NiO nanostructures exhibit high crystallinity and a honeycomb-like morphology. We successfully integrated these nanoparticles into a dye-sensitized solar cell (DSSC), demonstrating their viability as a counter electrode. The cell exhibits promising performance, with a short-circuit current density of 0.113 mA cm ^−2 and an efficiency of 0.0057%. This study presents a straightforward, cost-effective, and environmentally friendly method for bioengineering NiO honeycomb-like nanostructures, thereby paving the way for sustainable energy solutions.

Low-bandgap polymer-based organic solar cells (OSCs) exhibit broad optical absorption; however, their limited active-layer thickness restricts light harvesting, thereby constraining their power conversion efficiency (PCE). In this work, we employed plasmonic nanoparticles (NPs) to enhance light absorption in thin OSCs through tailored and broadened localized surface plasmon resonance (LSPR). Specifically, narrow-band quasi-spherical silver nanospheres (Ag Q-NSs) and broadband anisotropic gold nanorods (Au NRs) were incorporated into PTB7-Th:PC71BM-based active layers (ALs). The maximum PCE for devices with Ag Q-NSs were first optimized at 3 wt%, and the same concentration of Au NRs was applied for direct comparison. Devices modified with Ag Q-NSs exhibited an increase in short-circuit current density (Jsc) from 16.22 mA cm−2 (pristine) to 20.74 mA cm−2, while Au NR incorporation further improved the Jsc to 21.32 mA cm−2 due to their broader LSPR, which more effectively matches the absorption spectrum of PTB7-Th. Consequently, the PCE increased from 5.23% (pristine) to 6.49% for Ag Q-NS-modified devices and to 7.03% for Au NR-incorporated devices. The enhanced Jsc and PCE are attributed to increased optical absorption arising from LSPR and a significantly broadened external quantum efficiency (EQE) response. In addition to optical effects, the EQE enhancement indicates reduced bimolecular and trap-assisted recombination as confirmed by intensity dependent measurements. Notably, the effective recombination lifetime increased by nearly two-fold in NP-embedded devices, confirming improved charge generation and collection. Furthermore, three-dimensional finite-difference time-domain (3D-FDTD) simulations reveal distinct enhancement mechanisms: predominantly far-field scattering in Q-Ag NS-based devices and strong near-field enhancement in Au NR-based devices. These findings demonstrate that rational tuning of NP LSPR properties provides an effective strategy to achieve optimal spectral alignment with low-bandgap polymers, thereby maximizing plasmonic light harvesting and significantly enhancing OSC performance.

Herein, 3D/2D-Sn based perovskite heterostructure thin films were prepared by sequential physical vapor deposition (SPVD) and vacuum passivated by physical vapor treatment using Guanidinium tetrafluoroborate (GuaBF4). The effect of GuaBF4 surface treatment on the structural, optical, morphological and electrical properties of 3D/2D-Sn perovskite thin films as well as solar cell device performance was investigated. XRD results revealed a better film quality with high degree of crystallinity in GuaBF4 treated films. Morphological studies showed that the introduction of GuaBF4 led to an increase in grain size from 320.6 to 388.7 nm with a reduction in surface roughness. The grain growth and smoother films were attributed to secondary crystallization of the perovskite and the effective passivation of defects respectively induced by GuaBF4. Furthermore, the treated films exhibited a much higher PL intensity than the pristine films demonstrating the suppression of nonradiative recombination through passivation of surface defects and control of Sn2+ oxidation. As a result, the GuaBF4 device showed an improvement in the power conversion efficiency (PCE) of 5.4 % with low hysteresis compared to the pristine devices with PCE of 3.9 %. Notably, stability studies on the films and the devices revealed an improved stability of both the films and the device with GuaBF4. This was attributed to the synergistic contributions of Gua+ and BF4- towards defect passivation and suppression of Sn2+oxidation. Our study suggests a solvent-free preparation and treatment process of 3D/2D-Sn based perovskite heterostructures for improved film quality and solar cell performance.

Limited light absorption constrains the power conversion efficiency of thin-film organic solar cells (OSCs). Plasmonic nanoparticles offer an effective strategy for enhancing light trapping without increasing absorber thickness. In this work, mixed cubic and ellipsoidal colloidal Cu nanoparticles (c-Cu NPs) were incorporated into the ZnO electron transport layer (ETL) of inverted PBDD4T:PC71BM-based OSCs at volume ratios of 0, 0.25, 0.5, and 1% to exploit their dual plasmonic response. An optimal loading of 0.5% c-Cu NPs increased the PCE from 5.05% in the pristine device to 9.11%, representing an improvement of over 80% through simultaneous enhancements in the open-circuit voltage, short-circuit current density, and fill factor. The external quantum efficiency was enhanced by more than 50%, which is attributed to the broadband localized surface plasmon resonance of mixed-shaped Cu nanoparticles, resulting from near-field enhancement and forward scattering effects. The overall performance improvement is ascribed to the synergistic enhancement of charge generation, carrier mobility, and charge collection. Furthermore, the reduced defect density and smoother morphology of the c-Cu NPs-embedded ZnO ETL facilitate more efficient charge transfer and collection in the devices.

Copper nanorods (CuNRs) were synthesized through hydrothermal reduction and used as dopants in the buffer transport layer of polymer solar cells. The CuNRs were incorporated into the hole transport layer of thin-film organic solar cells (TFPSCs) to facilitate charge transport processes. The investigation employs a conventional device architecture for fabricating the solar cells. The results show that the power conversion efficiency (PCE) increased from 3.93% (pristine device) to 5.60% (device with 2% CuNRs), representing an improvement of over 42% compared to the pristine device. The enhanced performance is primarily attributed to the improved localized surface plasmon resonance induced by the CuNRs into the PEDOT:PSS, which enhances charge transport at the interface and reduces charge carrier recombination. In the optimized device with CuNRs doped in the PEDOT:PSS hole transport layer, the highest recorded PCE was 5.60%, demonstrating this approach's effectiveness of the CuNRs in the HTL. The effective use of CuNRs to enhance charge transport and plasmonic effects in thin-film organic solar cells.

Organic solar cells (OSCs) are a potential alternative to photovoltaic devices due to affordability. However, the power conversion efficiency (PCE) of OSCs still suffers due to charge recombination, leading to limitations in their commercialisation. The application of cathode interlayers in OSCs has garnered much interest in renewable energy due to their low-temperature fabrication. In this study, various concentrations of colloidal copper nanorods (CuNRs) have been employed to enhance light scattering in perylene diimides functionalized with amino oxide (PDINO) cathode interlayer. The 56.13 nm long CuNRs have increased the absorbance of PDINO, showing enhancement in localised surface plasmonic resonance (LSPR) observed at ∼525 nm. Due to the LSPR, CuNRs have significantly improved the PCE of ITO/PEDOT:PSS/P3HT:PCBM/PDINO:CuNRs/Ag device by 36.28% compared to the pristine device, indicating a simple and low temperature method of fabricating efficient OSCs.

2D-PEA(2)SnI(4) perovskite thin films were prepared by sequential physical vapor deposition (SPVD) technique. The effect of low substrate deposition temperature, annealing time, and PEAI thickness on structural, optical, and morphological properties of 2D-PEA(2)SnI(4) thin films was investigated. The results show that early-stage crystallization of SnI2 films before subsequent evaporation of PEAI hinders the efficient interdiffusion of the perovskite precursors. Films deposited at low substrate temperature (similar to 18 degrees C) exhibited similar to 300 % carrier lifetime improvement from 0.14 to 0.56 ns, suggesting a reduction of defect density and suppression of nonradiative recombination. FE-SEM micrographs revealed uniformly deposited films with densely packed grain size ranging from 92.50 to 453.1 nm and minimum pinholes. AFM results showed that surface roughness decreased from 138.2 to 50.99 nm as annealing time increased from 0 to 60 min. Similarly, surface roughness increased from 18.02 to 50.99 nm as PEAI thickness increased from 40 to 500 nm. XRD results revealed an improvement in crystallinity and average crystallite size as annealing time and PEAI thickness increased. This work suggests a way of improving the reaction between 2D-Sn-based perovskite precursors using the SPVD technique by controlling the substrate temperature and highlighting the role of substrate deposition temperature, film thickness, and annealing time towards crystallization of the perovskite.

This study used the sequential physical vapor deposition (SPVD) technique to grow poly-crystalline yellow phase cesium lead triiodide (gamma-CsPbI3). The effect of CsI thickness on structural, optical, morphological, and electrical properties of gamma-CsPbI3 was investigated. Crystallographic parameters of gamma-CsPbI3 as-deposited and 100 degrees C annealed pure-phase were determined using X-ray diffraction (XRD). Computed lattice constants were a = 4.88, b = 9.96, and c = 16.5 angstrom, with an average crystallite size increasing from 170 - 243 nm, and micro-strain decreasing with an increase of cesium iodide (CsI) thickness from 200 to 500 nm. Field-emission scanning electron microscopy (FE-SEM) images showed uniform surface coverage with polycrystalline grains. Average grain size increased from 168 to 235 nm with increasing CsI thickness, resulting in large, pinhole-free, and tightly packed grains. Furthermore, atomic force microscopy (AFM) surface analysis demonstrated a reduction in surface roughness from 44.0 to 38.3 nm as CsI thickness increased from 200 to 500 nm. The ultraviolet-visible (UV-Vis) spectra showed an increase in bandgap from 2.24 to 2.38 eV for as-deposited and a decrease from 2.37 to 2.05 eV for annealed films as the thickness of CsI increased. Current-voltage (J-V) measurements revealed a correlation between the trap-filled limit voltage (VTFL) and defect density. For electron-only devices with film thicknesses of 300, 400, 500, and 600 nm, the trap state densities were found to be 1.40 x 1015, 1.95 x 1015, 2.12 x 1015, and 2.39 x 1015 cm-3, respectively. The corresponding electron mobilities were 2.34 x 101, 6.30 x 101, 4.72 x 102, and 1.07 x 102 cm2/V.s. Additionally, perovskite solar cells (PSCs) fabricated under ambient air conditions revealed an improvement in power conversion efficiency (PCE) from 2.0 to 4.93 % for the FTO/c-TiO2/CsPbI3/ Au architecture. This work suggests a way of improving precursor's reaction using SPVD by controlling the film thickness, reducing defect density through SPVD, and therefore highlighting film thickness optimization in perovskites.

Metal halide perovskites such as CsPbI2Br are promising candidates for next-generation optoelectronic devices due to their tuneable bandgaps, high light absorption, and solution processibility. However, their practical application is hindered by structural purity, high defect densities, and non-radiative carrier losses, all of which limit efficiency and long-term stability. Recent strategies to mitigate these challenges involve compositional engineering with bulky organic cations and careful control of post-deposition annealing, but the combined influence of thermal processing and partial organic substitution on CsPbI2Br remains insufficiently understood. In this work, we report the synergistic impact of thermal annealing and partial organic cation substitution on the structural, morphological, and optoelectrical properties of CsPbI2Br perovskite thin films. Varying the annealing temperature and the substitution of Cs+ with octadecyl ammonium iodide (ODAI) can tune the crystallinity, defect density, and carrier recombination properties. X-ray diffraction analysis revealed a tetragonal crystal structure with optimal crystallinity at 240 ℃ and signs of phase transition at 300 ℃. Field emission scanning electron microscopy images confirm enhanced grain size and uniformity upon substitution with 15 mol

Transition metal-oxides have gained research attention for applications in optoelectronics devices like dye-sensitized solar cells (DSSCs). This contribution presents an α-Fe2O3-Pt DSSC configuration. An in-situ hydrothermal technique was used to grow spherically shaped α-Fe2O3 thin films on an FTO substrate, forming the photo-anode. The surface morphology, structural, and optical properties were characterized by standard techniques, confirming the samples’ purity. Pt was drop-cast on the FTO substrate, forming the counter electrode. The photo-anode was soaked in N719 ruthenium dye for 24 h. The electrodes were assembled using crocodile clips, and the iodide electrolyte was injected into the space between them. At an intensity of 100 mW/cm2, the α-Fe2O3-Pt DSSC yielded a short-circuit photocurrent density, open-circuit voltage, fill factor, and efficiency of 0.098 mAcm−2, 0.410 V, 0.247, and 0.01

2D-PEA2SnI4 perovskites thin films were prepared by sequential physical vapor deposition (SPVD), and passivated in vacuum using guanidinium tetrafluoroborate (GuaBF4). The effect of GuaBF4 on stability, optical, morphological, electrical, and structural properties of PEA2SnI4 films was investigated. The introduction of GuaBF4 improved the film morphology and crystallinity with the resulting films exhibiting enlarged grain sizes and low surface roughness. Raman and FTIR results showed that GuaBF4 did not change the structural phase and the functional group of the perovskite, but rather confirmed an additive-perovskite interaction. PL and carrier lifetime measurements revealed a 1.8 and 2-folds increment in intensity and lifetime respectively, attributed to suppression of non-radiative recombination in GuaBF4 treated films. XRD, UV-Vis and FE-SEM stability studies showed that GuaBF4 treatment significantly improved the stability of the films. This study suggests an effective strategy for deposition of solvent-free additive based 2D-Sn perovskite high quality films that are stable and reproducible.

In this work, direct passivation of methylammonium tin iodide thin films (MASnI3) with 4-fluorophenethylammonium iodide (4-FPEAI) eliminating use of toxic solvents and without annealing through sequential physical vapour deposition (SPVD) is reported. The stoichiometry of MASnI3 was achieved by depositing 100 nm of SnI2 and 300 nm of MAI, then annealing for 40 min. Subsequently, 4-FPEAI was deposited on top of MASnI3 with varying thicknesses of 5, 7 and 9 nm. The film's crystallinity was enhanced as FPEAI thickness increased from 5 nm to 7 nm, then reduced to 9 nm, as depicted by XRD. Consequently, the film's crystallite size increased from 35.51, 49.70, and 52.35 nm at 0, 5, and 7 nm FPEAI treatment and decreased to 42.46 nm at 9 nm FPEAI passivation, respectively. Pristine MASnI3 films showed many pinholes and grain boundaries, while FPEAI modified films exhibited a smooth surface with larger grains and fused grain boundaries (GBs), as revealed by SEM and AFM images. FPEAI filled the voids in the film and acted as a centre for nucleation, enhancing grain growth and lowering surface roughness. The grain sizes obtained were 392.9, 408.9, 444.6 nm, and 308.7 nm for 0, 5, 7 and 9 nm FPEAI treated films. Surface defects and GBs were significantly suppressed in the 4-FPEAI modified film, as revealed by a strong PL emission and reduced defect density. XRD measured after 24 h of nitrogen storage showed that FPEAI modified films displayed better stability where the perovskite peaks were more intense than the bare film, which degraded quickly. FPEAI, being hydrophobic, prevented moisture infiltration into the film through defect passivation, enhancing its stability. Hence, FPEAI passivation improved the optical, morphological and structural properties as well as the stability of MASnI3 films, which is favourable for application in optoelectronic devices.