Optical Transparency Research Articles

A Polymeric Two-in-One Electron Transport Layer and Transparent Electrode for Efficient Indoor All-Organic Solar Cells.

Transparent electrodes (TEs) are vital in optoelectronic devices, enabling the interaction of light and charges. While indium tin oxide (ITO) has traditionally served as a benchmark TE, its high cost prompts the exploration of alternatives to optimize electrode characteristics and improve device efficiencies. Conducting polymers, which combine polymer advantages with metal-like conductivity, emerge as a promising solution for TEs. This work introduces a two-in-one electron transport layer (ETL) and TE based on films of polyethylenimine ethoxylated (PEIE)-modified poly(benzodifurandione) (PBFDO). These PEIE-modified PBFDO layers exhibit a unique combination of properties, including low sheet resistance (130 Ω sq-1), low work function (4.2 eV), and high optical transparency (>85% in the UV-vis-NIR range). In contrast to commonly used poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), the doping level of PBFDO remains unaffected by the PEIE treatment, as verified through UV-vis-NIR absorption and X-ray photoelectron spectroscopy measurements. When employed as a two-in-one ETL/TE in organic solar cells, the PEIE-modified PBFDO electrode exhibits performance comparable to conventional ITO electrodes. Moreover, this work demonstrates all-organic solar cells with record-high power conversion efficiencies of >15.1% under indoor lighting conditions. These findings hold promise for the development of fully printed, all-organic optoelectronic devices.

Analysis of micro-hole formation in titanium nanofilms using a low power CW laser

This study investigates the mechanisms and dynamics governing microhole formation in titanium nanofilms under the influence of a continuous-wave low-power laser emitting at 1070 nm. Two distinct configurations were explored: one in which the laser interacted with the titanium film in an air environment (referred to as configuration AM), and the other in which the laser beam passed through glass before reaching the titanium film (referred to as configuration SM). Our experiments demonstrated that microhole formation is possible in both configurations. However, the threshold powers, hole characteristics, and time scales involved differ significantly between AM and SM configurations. Temperature distribution simulations, based on a linear absorption model, revealed notable differences in peak temperatures between these two configurations, primarily attributed to variations in focal spot size and Fresnel losses. These temperature variations resulted in significantly different mechanisms of material removal in both configurations. In the AM configuration, the boiling temperature was not achieved, even at the highest power; however, a melting pool was formed at powers exceeding 50 mW. Thus, the primary driver of microhole formation was the Marangoni effect, which caused molten material to flow tangentially towards the edges of the molten pool. Furthermore, titanium oxidation was identified as a competing process contributing to changes in optical transparency and potentially inhibiting the complete formation of holes. Conversely, within the SM configuration, boiling temperatures are easily achieved, leading to localized boiling and the formation of gas bubbles near the glass–titanium interface. As a result, the rupture of the bubble through the capping molten layer led to a vigorous expulsion of both gas and material, allowing for the creation of microholes even at remarkably low laser power levels (10 mW). Notably, in this configuration, the influence of titanium oxidation is negligible due to the relatively short time scale involved (hundreds of microseconds).

Synthesis and gasochromic hydrogen sensing properties of sodium tungsten bronze films by atmospheric flame vapor deposition

This study explores the gasochromic hydrogen sensing capabilities of Pd-coated NaxWO3 thin films prepared via Flame Vapor Deposition (FVD) on soda-lime glass substrates. Employing an oxy-hydrogen generator and varying substrate temperatures (100–450 °C) were investigated. X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) revealed a transition from Na0.1WO3 to Na2W6O19 phases, increased crystallite size (5.4–35.5 nm), and morphological changes from porous to dense structures with temperature. The films exhibited good optical transparency (70–95%) in the visible and near-infrared, with the sample deposited at 350 °C (S350) showing the maximum transmittance. The gasochromic hydrogen sensing performance of Pd/NaxWO3 films was evaluated. The sensor response increased with operating temperature, reaching an optimal performance at 300 °C. The sample S350 exhibited the fastest response (51 s) and recovery (30 s) times with a linear calibration curve limit of detection (LOD) of 46 ppm. Repeated cycling tests indicated stable and reversible performance. Finally, the sensing mechanism was described.

Sustainable Approaches for the Fabrication of Nanocellulose-Polyamide Membrane Based on Waste Date Palm Leaves for Water Treatment

A vast amount of agricultural waste, such as dried leaves, stems, pits, seeds, etc., are produced by date palm trees in Saudi Arabia each year. This waste is an excellent source of degradable biomass suitable for many uses. Crystalline nanocellulose (CNC) is one of the most important nanomaterials that can be used in various applications. Due to its unique properties, which include biorenewability, optical transparency, high mechanical strengths, and sustainability, nanocrystalline cellulose has become a significant nanomaterial in recent years. In this study, CNC was isolated from the waste date palm leaves and used for the production of PA-modified membranes for water treatment by reverse osmosis membrane technology. The membranes were prepared by surface polymerization with the polyamide as a selective layer on the polysulfone support film. Three membranes were produced, two with 0.01% and 0.02% (w/v) CNC and the third with PA-free CNC for comparison. Each membrane produced was tested using different characterization techniques. The polyamide membrane with 0.01% w/v CNC had a higher water permeability of 43.25 L/m2 h bar than the membranes with 0% w/v CNC (36.25 L/m2 h) and 0.02% w/v CNC (42.85 L/m2 h bar). Under the same conditions, salt retention was also found to be above 98% for both NaCl and MgSO4 for the two modified membranes. The contact angle was found to be 68.04±3.7, 72.83±0.8, and 63.76±5.5 for PA(0%CNC), PA-CNC (0.01% w/v), and PA-CNC (0.02% w/v), respectively. The 0.01% PA-CNC membrane exhibited a higher water contact angle, greater hydrophobicity and lower surface roughness. As a result, the isolated CNC might be appropriate for use as a modifier agent for membrane fabrication and water treatment.

Transparent and high-porosity aluminum alkoxide network-forming glasses

Metal-organic network-forming glasses are an emerging type of material capable of combining the modular design and high porosity of metal-organic frameworks and the high processability and optical transparency of glasses. However, a generalizable strategy for achieving both high porosity and high glass-forming ability in modularly designed metal-organic networks has yet to be developed. Herein, we develop a series of aluminum alkoxide glasses and monoliths by linking aluminum-oxo clusters with alcohol linkers. A bulky monodentate alcohol modulator is introduced during synthesis and act as both network plasticizer and pore template, which can be removed by the subsequent solvent exchange to give gas accessible pores. Glasses synthesized with the modulator template exhibit well-defined glass transitions in their as-synthesized form and high surface areas up to 500 m2/g after activation, making them among the most porous glassy materials. The aluminum alkoxide glasses also have optical transparency and fluorescent properties, and their structures are elucidated by pair-distribution functions, spectroscopic and compositional analysis. These findings could significantly expand the library of microporous metal-organic network-forming glasses and enable their future applications.

Feasibility of biomass-based flexible and transparent AuNPs-acetylcellulose membrane for multifarious surface-enhanced Raman spectroscopy detection

BackgroundLignocellulosic biomass-based derivatives coupled with surface-enhanced Raman spectroscopy (SERS) technology have emerged as an appealing and indispensable tool in food safety and environmental monitoring for rapidly detecting trace contaminants like pesticide residues. The membrane material, serving as a substrate, ensures both sampling flexibility and test accuracy by directing the diffusion-adsorption process of the molecules. However, the existing membrane substrates, critical for the practical application of SERS, suffer from issues such as costly, intricate fabrication procedures, or restricted detection capabilities. ResultsHerein, we present a flexible, transparent, and biodegradable cellulose acetate membrane with gold nanoparticles (AuNPs) uniformly embedded, fabricated using a simple scraping method. This membrane achieved a limit of detection (LOD) of thiram pesticide in water at 10−8 g mL−1. The unique optical transparency of the substrates allowed for in-situ detection on surfaces, with an LOD of thiram reaching 30 ng cm−2. SignificanceFurthermore, SERS substrates made from corn stover-derived cellulose acetate enable the detection of various contaminants, highlighting their cost-effectiveness and eco-friendliness because of the abundance and low environmental impact of the raw materials.

Maximal Anderson localization and suppression of surface plasmons in two-dimensional random Au networks

Two-dimensional random metal networks possess unique electrical and optical properties, such as almost total optical transparency and low sheet resistance, which are closely related to their disordered structure. Here we present a detailed experimental and theoretical investigation of their plasmonic properties, revealing Anderson (disorder-driven) localized surface plasmon resonances of very large quality factors and spatial localization close to the theoretical maximum, which couple to electromagnetic waves. Moreover, they disappear above a geometry-dependent threshold of approximately 1.7 eV in the investigated Au networks, explaining their large transparencies in the optical spectrum. Published by the American Physical Society 2024

Initializing Compression Stress to Stabilize the Phase Homogeneity in Bifacial Semitransparent Perovskite Solar Cells

AbstractSemitransparent perovskite solar cells (ST‐PSCs) hold great promise for various commercial applications, including building integrated photovoltaics and tandem solar cells. The all‐inorganic perovskite, known for its outstanding optical transparency and thermal stability, emerges as a top contender for ST‐PSCs. However, challenges persist due to phase segregation, which hampers charge carrier transport and operational stability. In this study, an approach is proposed to address these challenges by employing strain engineering to reconstruct the perovskite texture, eliminating inhomogeneities within the perovskite film. The crucial role of compressive strain in stabilizing lattice rigidity and suppressing light‐induced ion migration is demonstrated. Furthermore, a transparent light‐harvesting architecture is devised utilizing a sandwiched layer of gold embedded between MoO3. This design enhances power generation by efficiently harnessing incident light from both the front and rear panel surfaces. Therefore, bifacial ST‐PSCs achieve an equivalent efficiency (ηeq) of 13.97% with an average visible light transmittance of 41.58%, yielding an outstanding light utilization efficiency of up to 5.8%. This research not only advances the understanding of perovskite material phase‐segregation behavior but also introduces an effective strategy for enhancing optical gain without compromising the semitransparent characteristics.

Neuron-astrocyte interaction-inspired percolative networks with metal microdendrites and nanostars for ultrasensitive and transparent electronic skins

Biological systems provide innovative designs for electronic devices, optimizing network configurations for high-performance signal transmission with minimal energy consumption. The brain, as one of the most complex biological structures, demonstrates efficient network design through the multiscale radial networks of neurons and astrocytes. Emulating these brain networks offers a blueprint for the development of ultrasensitive pressure sensors for electronic skin, aiming to provide a more intuitive and sensitive mode of interaction between humans and machines. Herein, we propose a neuromorphic percolative network inspired by neuron-astrocyte interactions for ultrasensitive pressure sensors employing metal microdendrites and nanostars. Electromechanical investigation through representative volume elements simulation reveals that the optimized arrangement of microdendrites and nanostars in the neuromorphic percolative system enhances the percolation threshold and probability. Following these simulation results, we developed a neuromorphic percolative polyurethane (NP-PU) matrix utilizing the metal microdendrite-nanostar networks. The augmented quantum tunneling effect in the NP-PU matrix was investigated through electrochemical impedance spectroscopy and capacitance analysis. The fabricated piezoresistive pressure sensor with the NP-PU matrix shows ultrahigh sensitivity (160.3 kPa−1) at a low pressure range and a low limit of detection resolution (4 Pa), enabled by multi-channel quantum tunneling in the metal particle networks. Furthermore, the sensor maintains excellent mechanical flexibility and high optical transparency (75.4 %), improving its efficacy in applications like electronic skin and force touch panel. Our study highlights the potential of leveraging biological system-inspired network designs for crafting advanced electronic devices.

Flexible and transparent ultra-broadband low-profile frequency selective rasorber

An ultra-broadband, low-profile, flexible, and transparent frequency selective rasorber (FSR) is designed based on indium tin oxide (ITO) film. The -1 dB transmission band of the resistive sheet and the bandpass FSS are 0.10 - 8.61 GHz and 3.09 - 7.09 GHz, respectively. By integrating the resistive sheet and the bandpass FSS, a transmission band ranging 1.95 - 6.27 GHz with |S21| larger than -3 dB is achieved, alongside an absorption band ranging 7.34 - 10.83 GHz with absorptance larger than 0.8. Additionally, the FSR presented in this paper is designed by single-layer bandpass FSS and adopts coplanar coupling to realize an ultrabroad transmission band. Its ultra-broadband absorption and transmission performance are verified through experiments and the working principles are analyzed through an equivalent circuit model (ECM). The proposed FSR possesses unique advantages integrating ultrabroad band, optical transparency, flexibility, low profile, and light weight. The proposed FSR exhibits the potential to reduce the out-of-band radar cross-section (RCS), with its optical transparency showing promise for window applications.

PEDOT:PSS-based electronic “paper” with high surface-interface and mechanical strength and ultra-long wet-resistant capacity

Organic electrochromic conducting polymers (CPs) are at the forefront of flexible and ultra-thin display electronics. Solution processable poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) exhibits excellent electrical and electrochemical behavior in line with great processability, stability, and other promising properties. However, their uses are limited by the weak mechanical properties, wet instability, as well as inevitable conflicts among different functionalities and structural characteristics, etc. In this study, we designed and fabricated a high-mechanical-strength electronic “paper”, PEDOT:PSS/PEG-UPy film, employed a thermoplastic polyurethane poly(ethylene glycol)-2-amino-5-(2-hydroxyethyl)-6-methylpyrimidin-4-ol (PEG-UPy) using diverse processing (drop coating, spin coating, blade coating and 3D printing) of its “electric ink (E-ink)” from the mechanical mixture of its isopropanol (IPA) solution with aqueous PEDOT:PSS dispersion. Compared to PEDOT:PSS film, the incorporation of supramolecular chain-expanding unit 2-amino-4-hydroxy-6-methylpyrimidine (UPy) into the PEG-UPy molecular backbone resulted into optimized self-supporting (substrate-free) film of PEDOT:PSS/PEG-UPy(10 wt%) which showed great flexibility, enhanced mechanical strength (elongation at break 47.08 %, tensile strength of 19.16 MPa, toughness 7.973 MJ m−3), considerable electrical properties (0.509 S cm−1), desirable physical properties including resistance to abrasion and solvent-wiping, and excellent surface-interface properties (e.g., hardness of 3H, adhesion of level 0, glossiness of 91). Its electrochromic capabilities include an optical contrast (ΔT) value of 67 %, a fast redox reaction (4 s and 3 s, respectively), and a coloring efficiency (722.19 cm2 C−1). Similar to paper, they can be easily tailored or folded into a variety of forms, but have greater advances on dense morphology, flat surface, considerable optical transparency (79.5 %), as well as robust resistance to mechanical damage (in the case of bending, stretching, and folding, etc.), water (immersing > 150 days), and dirt. The combined effect of molecular design of PEG-UPy, abundant hydrogen-bonded cross-linking interaction and “good” solvent effect of IPA to PEDOT:PSS play important roles in this system. This is the first work on solution processable PEDOT:PSS-based electrochromic “paper” being able to meet much comprehensive performance requirements for the application in practical complex working environment.

Impacts of Dislocations and Residual Thermal Tension on Monolithically Integrated InGaP/GaAs/Si Triple‐Junction Solar Cells

Direct epitaxy of III−V materials on Si is a promising approach for highly stable, scalable, and efficient Si‐based multijunction solar cells. However, challenges lie in overcoming epitaxial dislocations and residual thermal strain generated by lattice constant and thermal‐expansion‐coefficient mismatches, respectively. Herein, a 15.2% efficient InGaP/GaAs/Si triple‐junction solar cell with an open‐circuit voltage of 2.36 V by using In0.10Al0.16Ga0.74As digital‐alloy dislocation filter layers is first demonstrated. The filter layers are utilized in the n‐GaAs buffer on Si to reduce threading dislocation density to 4 × 107 cm−2 while maintaining optical transparency to Si bottom cell. Then, the impacts of threading dislocations and residual tension on InGaP/GaAs/Si cells are systematically investigated by comparing them to the co‐grown InGaP/GaAs tandem cells on a native GaAs substrate. Based on the comparative analysis, a strategy to suppress material deformation and defect formation toward 30% efficient InGaP/GaAs/Si triple‐junction solar cells is proposed.

Wideband optically transparent absorber based on multilayer ITO films with high absorption rate

In this paper, a wideband optically transparent absorber based on multilayer indium tin oxide (ITO) films is designed, fabricated, and measured. The structure uses polyethylene terephthalate (PET) and ITO films to replace the dielectric substrate and metal pattern of the traditional absorber to achieve optical transparency characteristics. The absorption of the proposed absorber is above 90% from 4.92 to 24.55 GHz and exceeding 95% in the range of 5.74 ∼ 21.85 GHz, respectively, under normal transverse electric (TE) and transverse magnetic (TM) polarized incidences. Moreover, it shows outstanding stability with various incident angles over a wide range. A prototype of the proposed absorber is fabricated and experimentally verified, with good measurement results. The optical transparency and great absorption performance make the absorber a promising candidate for transparent electromagnetic compatibility.

Effect of Angular Momentum–Dependent Transparency on the Neutron-Nucleus Cross Section

We study the effect of the angular momentum dependence of the optical potential transparency on the neutron-nucleus cross section. In this work, we derive a functional form of the neutron-nucleus cross section with respect to spherical optical potential using the collision matrix and modify it. We also apply an analytical model (Ramsauer) to the square optical potential and the optical model using the TALYS 1.96 code to get the angular momentum–independent transparency and demonstrate the effect of the angular momentum dependence via comparison of two models. In this work, we calculate the neutron cross sections for 40 ≤ A ≤ 90 nuclei, with energies 100 MeV ≤ En ≤ 200MeV theoretically, the for ℓ ≠ 0 case. We find that the angular momentum dependence of the transparency treats good calculations of the neutron-nucleus cross section; a finite number of angular momentums will contribute appreciably to the nuclear reaction. The present study on smooth optical potential leads to useful insight into the mechanisms of neutron-induced reactions, particularly for medium nuclei at high energies.

From Molecular Design to Practical Applications: Strategies for Enhancing the Optical and Thermal Performance of Polyimide Films.

Polyimide (PI) films are well recognized for their outstanding chemical resistance, radiation resistance, thermal properties, and mechanical strength, rendering them highly valuable in advanced fields such as aerospace, sophisticated electronic components, and semiconductors. However, improving their optical transparency while maintaining excellent thermal properties remains a significant challenge. This review systematically checks over recent advancements in enhancing the optical and thermal performance of PI films, focusing on various strategies through molecular design. These strategies include optimizing the main chain, side chain, non-coplanar structures, and endcap groups. Rigid and flexible structural characteristics in the proper combination can contribute to the balance thermal stability and optical transparency. Introducing fluorinated substituents and bulky side groups significantly reduces the formation of charge transfer complexes, enhancing both transparency and thermal properties. Non-coplanar structures, such as spiro and cardo configurations, further improve the optical properties while maintaining thermal stability. Future research trends include nanoparticle doping, intrinsic microporous PI polymers, photosensitive polyimides, machine learning-assisted molecular design, and metal coating techniques, which are expected to further enhance the comprehensive optical and thermal performance of PI films and expand their applications in flexible displays, solar cells, and high-performance electronic devices. Overall, systematic molecular design and optimization have significantly improved the optical and thermal performance of PI films, showing broad application prospects. This review aims to provide researchers with valuable references, stimulate more innovative research and applications, and promote the deep integration of PI films into modern technology and industry.

High Refractive Index, Low Birefringence Holographic Materials via the Homopolymerization of 1,2-Dithiolanes.

High refractive index, low birefringence photopolymers were created via the radical-mediated, ring opening homopolymerization of 1,2-dithiolane functionalized monomers and were subsequently evaluated as holographic recording media. This investigation systematically characterized the reaction kinetics, thermodynamics, and volume shrinkage of the 1,2-dithiolane homopolymerization as well as the optical transparency, refractive index, birefringence, and holographic performance of multifunctional 1,2-dithiolane functionalized monomers and their resultant polymers. Real-time kinetic and thermodynamic analyses of a monofunctional 1,2-dithiolane monomer, lipoic acid methyl ester (LipOMe), indicated rapid monomer conversion, exceeding 90% in 60 s, with an overall enthalpy of reaction of 18 ± 1 kJ/mol. The ring-opening polymerization resulted in low shrinkage (10.6 ± 0.3 cm3/mol dithiolane) and a significant bulk refractive index increase (0.030 ± 0.003). The resulting photopolymers exhibited high optical transparency, minimal haze, and negligible birefringence, suggesting the potential of 1,2-homopolymers as optical materials. To further explore the specific capabilities for use as high-performance holographic recording applications, several multifunctional monomers were synthesized with the ethanedithiol lipoic acid monomer (EDT-Lip2) selected for experimentation. Holographic diffraction gratings written using this monomer achieved a peak-to-mean refractive index modulation of 0.008 with minimal haze and birefringence.

Investigation on Physicochemical Properties of Nonlinear Optical (NLO) Single Crystal: Rubidium Hydrogen Fumarate

A solvent evaporation method produced an optically high-quality semiorganic single crystal of Rubidium hydrogen fumarate (RbHF) at room temperature. The structural analysis reported that the RbHF crystallized in triclinic crystal system with centrosymmetric space group P1¯. The Powder XRD pattern indicates the grown crystal have good crystalline nature. FTIR spectroscopy examined the functional group and bonding in the grown molecule. A optical transparency of about 88% were observed in RbHF and having energy bandgap of 3.9 eV were calculated using Tauc’s plot. The grown crystals were thermally stable upto 170°C. Mechanical and dielectric analysis has been carried and their properties were discussed in detail. Intermolecular interactions were studied using Hirshfeld surface maps and 2D fingerprint plots. The grown crystal have positive photoconductivity nature. A Z-scan were used to study the third order NLO response in RbHF crystal. The third order nonlinear susceptibility of RbHF crystal was estimated as (χ3) = 1.60244 × 10-08 esu, nonlinear absorption coefficient (β) = 6.39395 × 10-5 cm2/W and nonlinear refractive index (n2) = 9.15822 × 10-12 cm/W. The observed results of the RbHF single crystal show, it has the potential application in optical and optoelectronic devices.

Defect engineering by annealing: Managing the trade-off relationship between photochromic and electrical properties in KNN-based translucent ceramics

Rare-earth-doped transparent ferroelectrics exhibit outstanding optical transparency, photoluminescence (PL), photochromic (PC) and various electrical properties, showing potential for use in optoelectronic applications. However, there is an inevitable trade-off relationship between optical and electrical coupling during the integration of multifunctionality. In this work, Ba2+, Ho3+ and Yb3+ were codoped in KNN translucent-ferroelectric ceramics (as a model material) to overcome the contradiction between optical (transparency/PC) and electrical properties (resistivity/ferroelectricity). The defects (mainly oxygen vacancies) within the ceramics can be effectively regulated through annealing under different atmospheres. At the cost of a slight decrease in PC performance, the electrical properties significantly improved; i.e., for the optimal ceramic annealed in an oxygen atmosphere, both the maximum and remnant polarizations nearly doubled, and the resistivity significantly decreased compared to that of the original sample. A mechanism for regulating these properties was proposed. This research serves as a valuable example for adjusting the optical and electrical properties of other ferroelectrics through annealing.

Super foldable transparent paper by regulating the multi-scale structure of cellulose fibers

Transparent cellulose papers have emerged as a promising substrate and/or functional component for next-generation sustainable flexible electronics. However, obtaining transparent paper with folding endurance comparable to that of plastic films such as polyethylene terephthalate (PET) remains a major challenge, which was addressed in this study by modulating the multiscale structure (from molecular structure, aggregation structure to fibrous morphology) of wood fibers. Compared to the natural wood fibers, the modified fibers not only retained their length and cellulose degree of polymerization (DP) to a large extent, but also had lower crystallinity and improved swelling capability, which well preserved the fiber strength and dense intertwined fiber network, and led to stronger inter-fiber interactions in the final transparent paper. The obtained paper (CM-paper) exhibits an optical transparency of 91 % and a folding endurance of 37,466 times, comparable to that of commercial PET (39,955 folds). Furthermore, the underlying mechanism for the superior foldability of the transparent paper was unveiled at three scales is explored. Finally, the potential application of CM-paper in electromagnetic induction electrodes was demonstrated, where the CM-paper electrodes exhibit satisfactory conductivity after repeated rubbing. This work offers an innovative approach to produce transparent papers with outstanding foldability, which is expected to plastic replacement.

Effects of ALD Deposition Cycles of Al2O3 on the Morphology and Performance of FTO-Based Dye-Sensitized Solar Cells

In dye-sensitized solar cells (DSSCs), materials classified as Transparent Conducting Oxides (TCOs) have the capacity to conduct electricity and transmit light at the same time. Their exceptional blend of optical transparency and electrical conductivity makes them popular choices for transparent electrodes in DSSCs. Fluorine Tin Oxide (FTO) was utilized in this experiment. The optical and electrical characteristics of TCOs may be negatively impacted by their frequent exposure to hostile environments and potential for deterioration. TCOs are coated with passivating layers to increase their performance, stability, and defense against environmental elements including oxygen, moisture, and chemical pollutants. Because of its superior dielectric qualities, strong chemical stability, and suitability with TCO materials, aluminum oxide (Al2O3) was utilized as a passivating layer for the FTO. In this research work, Al2O3 was deposited via atomic layer deposition (ALD) to form thin mesoporous layers as a passivator in the photoanode (working electrode). The work focuses on finding an appropriate thickness of Al2O3 for optimum performance of the dye-sensitized solar cells. The solar simulation and sheet resistance analysis clearly showed 200 cycles of Al2O3 to exhibit an efficiency of 4.31%, which was the most efficient performance. The surface morphology and topography of all samples were discussed and analyzed.