Indium Tin Oxide Research Articles

Pronounced Role of Lithium-Controlling Polymer in Water-Processable/Halogen-Free All-Solid-State Electrolytes for Lithium Supercapacitors.

Polymeric solid-state electrolytes (SSEs) with environmentally friendly processes deliver safer and cleaner energy storage devices without fires and leakages than conventional liquid electrolytes. Here, water-processable halogen-free polymeric SSEs are demonstrated with high ion conductivity (≈6 mScm-1), prepared from aqueous solutions consisting of branched poly(ethylene imine) (bPEI), lithium hydroxide (LiOH), and poly(4-styrene sulfonic acid) (PSSA). The bPEI:LiOH:PSSA (PLP) SSEs with various PSSA molar ratios are applied to asymmetric supercapacitors with graphite-based anodes and indium tin oxide (ITO) counter electrodes. The PSSA molar ratio strongly affected the ion conductivity of PLP SSEs, leading to a maximum at PSSA = 40 mol%, owing to the role of PSSA in controlling the size of LiOH domains for better Li+ transport pathways. The enhanced ion conductivity enabled PLP-supercapacitors to build a high potential of 2.24V at PSSA = 40 mol%, compared to 1.64V at 0 mol%, upon galvanostatic charge/discharge at a current density of 0.2mAg-1. The endurance test shows that the supercapacitors with the PLP SSEs (PSSA = 40 mol%) can function stably with high capacitance retention (96.2%) for more than 5000 cycles, and ≈80% capacitance retention at 80 °C, supporting their practical use in high-safety supercapacitors and batteries.

Approaching the Limits of Transmittance and Sheet Resistance in MXene through Nanoimprinting-Blading of Inks.

Developing an advanced transparent conductive electrode (TCE) as a substitute for the fragile and high-cost indium tin oxide (ITO) is the top priority in the coming smart electronics era. Although two-dimensional transition metal carbides and nitrides (MXenes) have revealed great potential in the competition, the figure of merits (FoMe, defined as the ratio of direct current conductivity to optical conductivity) of reported MXenes TCEs are far below the minimum industrial requirement. Herein, we report on the breaking of FoMe limitation by a hybrid nanoimprint-blading technique to construct embedded MXene grids, where the fine slot channels are filled with MXene flakes and the space beyond is left empty, allowing more visible light to pass through, thus substantially improving the transmittance. Such a strategy decouples the correlation between transmittance and sheet resistance and achieves their individual regulation. As a result, we obtain an ultrahigh FoMe (∼84) surpassing most of other nonmetal TCEs and even being competitive to ITO. We demonstrate the application of MXene grid TCE in the electrochromic device, showing satisfactory switching time and excellent stability (>38,000 cycles). This work opens vast opportunities for MXenes to construct advanced flexible electronics for industrial applications.

Semiartificial Photoelectrochemistry for CO2-Mediated Enantioselective Organic Synthesis.

Photoelectrochemical (PEC) cells are under intensive development for the synthesis of solar fuels, but CO2 reduction typically only results in simple building blocks such as HCOO-. Here, we demonstrate that CO2-converting PEC cells can drive integrated enzymatic domino catalysis to produce chiral organic molecules by using CO2/HCOO- as a sustainable redox couple. First, we establish a semiartificial electrode consisting of three enzymes co-immobilized on a high surface area electrode based on carbon felt covered by a mesoporous indium tin oxide (ITO) coating. When applying a mild cathodic potential (-0.25 V vs the reversible hydrogen electrode (RHE)), CO2 is reduced to HCOO- using a W-formate dehydrogenase (FDHNvH) from Nitratidesulfovibrio vulgaris Hildenborough, which then enables the reduction of NAD+ to NADH by an NAD+-cofactor-dependent formate dehydrogenase from Candida boidinii (FDHCB). Subsequently, an alcohol dehydrogenase (ADH) uses NADH generated from CO2/HCOO- cycling to reduce acetophenone to chiral 1-phenylethanol in good enantiomeric excess (93%) and conversion yields (38%). Depending on the specific ADH (ADHS or ADHR), either (S)- or (R)-1-phenylethanol can be synthesized at pH 6 and 20 °C. To illustrate solar energy utilization, we integrate the three nanoconfined enzymes with a PEC platform based on an integrated organic semiconductor photocathode to allow for enantioselective synthesis (at +0.8 V vs RHE) based on a solar fuel device. This proof-of-principle demonstration shows that concepts and devices from artificial photosynthesis can be readily translated to precise and sustainable biocatalysis, including the production of chiral organic molecules using light.

Impact of Transparent Conducting Oxide on the Performance of Dye‐Sensitised Solar Cells for Indoor Applications

Improving the performance of dye‐sensitised solar cells (DSC) under artificial light sources and at low light intensities requires preserving the adequate electron transport properties in the sensitised photoanode that are characteristic of DSC operation at 1 sun. Besides, parasitic resistance and optical losses must be reduced. In this respect, the impact of the chemical and electrical properties of the transparent conducting oxide (TCO) has somehow been overlooked. Considering the systematic reduction of the electron diffusion length as the low quasi‐Fermi level regime is approached, subtle variations of the properties of the TiO2 photoanode and its interaction with the TCO substrate can compromise optimal performance under indoor illumination. In this work, the performance of DSCs fabricated with commercial fluorine‐doped tin oxide (FTO) and indium tin oxide (ITO) substrates, as well as newly prepared ITO substrates of varying conductivity, has been analysed. Furthermore, a variation of the preparation conditions for the TiO2‐based photoanodes was conducted, with thermal treatments at two different annealing temperatures (450 and 550°C). Photovoltaic characterisation and analysis of the impedance response reveal a low conductivity of the substrate proves to be only adverse under 1 sun illumination, deteriorating the fill factor due to the series resistance voltage drop. In contrast, under low illumination intensity, all studied substrates show comparable performance, which can be attributed to the negligible voltage drop over the series resistance related to the significantly lower photocurrent. As a consequence, the conductivity of the TCO substrate is less critical when selecting a substrate for indoor applications. However, the choice of TCO affects the quality of TiO2 photoanodes, leading to shorter diffusion lengths in some cases. Interestingly, the annealing temperature plays a critical role in homogenising the differences observed while also enhancing the diffusion length, ensuring efficient electron collection under low light conditions.

Investigation of Halogenated Metallic Phthalocyanine (InPcCl and F16CuPc)-Based Electrodes and Palm Substrate for Organic Solid-State Supercapacitor Fabrication

In this work, we report on the fabrication of a novel Organic Double-Layer Supercapacitor (ODLSC) using recycled palm as the substrate and electrodes based on halogenated indium and copper phthalocyanines. The electrodes were characterized using Reflectance, the Kulbeka–Munk function, and Fluorescence. Finally, their electrical behavior was evaluated, and the results were compared with those obtained for a more conventional supercapacitor fabricated on polyethylene terephthalate substrate and using indium tin oxide film for electrodes. Based on the experimental measurements of the fabricated ODLSC, the parameter identification of the classical equivalent circuit model was carried out using the Least Squares of Orthogonal Distances (LSOD) algorithm. The results indicated that the palm supercapacitor exhibited behavior more like that of traditional supercapacitors, as the root square mean error (RMSE) values in the model approximation of the experimental data were in the order of 10−7. Furthermore, the models obtained allowed a determination of the device’s Electrical Impedance Spectroscopy (EIS), revealing that the Palm SC-T1 exhibited capacitive behavior. In contrast, the manufactured Palm SC-T2, PET SC-T1, and PET SC-T2 devices exhibited inductive behavior. All the materials used in this work, such as the substrates, electrodes, separator membranes, and electrolytes, have a high potential to be used in organic supercapacitors.

NW-based sample preparation for ultrahigh vacuum STM imaging

Nanowires (NWs) of III-V semiconductors provide a promising platform for the development of electronic and photonic components of integrated circuits. For the development of complex NW-based devices, it is crucial to precisely study structural, electronic, and optical properties at the nanoscale. Scanning tunneling microscopy (STM) is commonly used to achieve such precision. In this work we optimize the tunneling contact parameters in an ultrahigh vacuum STM (at room temperature) for reproducible high-quality topographic imaging of conductive GaP NWs, especially promising for photonic integrated circuits. Two methods were employed for transferring NWs onto auxiliary conducting substrates: ultrasonication in liquid (deionized water or isopropyl alcohol) followed by drop casting and mechanical scratching. Five substrate materials were tested: highly oriented pyrolytic graphite, single crystal silicon wafers, thin films of nickel, indium tin oxide and gold. The experimental results showed that the tunneling contact parameters, substrate material, and transfer method significantly affect the quality of STM images. It was found that bias voltages of 7-10 V, tunneling current up to 400 pA, and image recording rates in the range of 500-1500 nm s-1were optimal, with nickel-coated substrates providing the best stability and image quality. Potentially harmful procedures for NW and substrate surfaces, such as ion treatment and high-temperature annealing, were avoided during the sample preparation. The results expand the understanding of STM studies of NWs and their applications in electronic and photonic devices.

Exceeding 13% Power Conversion Efficiency of Cu(In,Ga)(S,Se)2 Thin‐Film Solar Cells with AgNWs/TiOx Composite Transparent Conductive Window Layer

Indium tin oxide (ITO) is usually served as the transparent conductive electrode of Cu(In, Ga)(S, ‐Se)2 (CIGSSe) solar cells. However, ITO is fabricated by sputtering method, which will increase the cost of CIGSSe solar cells and prevent its large‐scale market applications in the future. Hence, it is particularly important to develop low‐cost transparent conductive window layers to replace the traditional ITO. Silver nanowires (AgNWs) are considered to be the most promising alternative to ITO. Compared with sputtered ITO, AgNWs have the advantages of high transmittance, low cost, and easy fabrication. Nevertheless, the poor adhesion and stability of AgNWs can prevent the transportation of carriers of CIGSSe solar cells. Here, we select amorphous TiOx as an adjuvant to fabricate AgNWs/TiOx composite transparent conductive layer to substitute the traditional ITO. Under the assistance of TiOx matrix, not only the connection, adhesion, and stability of AgNWs are greatly enhanced, but also the surface roughness of AgNWs is also reduced. The influence of AgNWs concentration on the performance of CIGSSe solar cells is investigated. When the AgNWs concentration is 2.5 mg/mL, the transmittance and sheet resistance of AgNWs thin film are 93.35% and 93 Ω/sq, respectively, and the devices achieved the highest efficiency of 13.59%.

Optimized Self‐Assembled Monolayer Coverage using Molybdenum Trioxide‐Modified Indium Tin Oxide for High‐Performance Organic Solar Cells

AbstractSelf‐assembled monolayers (SAMs) have recently emerged as promising candidates for interfacial materials in organic photovoltaics (OPVs). However, the quality and integrity of SAM growth are significantly influenced by the surface morphology of indium tin oxide (ITO) substrates, which can compromise the performance and reproducibility of OPVs. To achieve controlled and high‐quality SAMs assembly, this study presents an effective strategy to eliminate the sensitivity of SAM growth to polycrystalline ITO by depositing an amorphous molybdenum trioxide (MoO3) thin layer on top. The application of MoO3 can homogenize surface roughness and circumvent issues related to preferential grain orientation and distinct grain boundaries associated with ITO. This results in a more uniform and denser SAM coverage compared to direct growth on bare ITO. Consequently, the resulting OPVs based on the PM6/BTP‐eC9 system exhibit an outstanding power conversion efficiency of 19.9% (certified at 19.3%), primarily due to reduced interfacial defects and optimized active layer morphology. More importantly, the introduction of MoO3 between ITO and SAMs enhances the reproducibility of efficiency and the long‐term stability of devices compared to those based solely on SAMs. This progress highlights the importance of refining the ITO surface microstructure to facilitate favorable SAM formation and subsequently construct high‐performance OPVs.

Analysis of the Ambipolar Conduction of Tin Monoxide Thin-Film Transistors with Indium Tin Oxide Electrodes.

This study investigates the hole and electron conduction properties of thin-film transistors (TFTs) with a tin monoxide (SnO) channel and indium tin oxide (ITO) source/drain (S/D) electrodes, considering the adoption to three-dimensional (3D) NAND Flash. Compared to SnO TFTs with gold (Au) S/D electrodes, significant enhancement of electron conduction was observed when adopting ITO S/D electrodes. The ITO electrodes decreased the Schottky barrier height for electron injection, enhancing electron conduction and consequently inducing ambipolar conduction behavior. The ambipolar SnO TFT exhibited coexisting electron and hole channels, which induced a transition from normal to abnormal conduction properties. These transitioning conduction characteristics were analyzed, and a method to extract saturation mobility in ambipolar TFTs considering the electron-hole (e-h) recombination effect was proposed. Furthermore, bias-stress stability tests were conducted to examine the effect of the coexisting electron and hole channels on the carrier-trapping properties. This analysis provides valuable insights into the electrical characteristics of ambipolar TFTs, considering the coexisting electron and hole channels.

Interface Fermi‐Level Engineering for Selective Hole Extraction Without p‐Type Doping In Cdte Solar Cells to Reach High Open Circuit Voltage (>1 V)

Solar cells with an open‐circuit voltage (Voc) over 1 V are demonstrated utilizing an n‐type CdTe/MgCdTe double‐heterostructure (DH) absorber and an n‐type indium tin oxide (ITO) transparent layer to form a hole‐selective contact. The n‐type ITO layer is directly deposited on the MgCdTe top barrier layer for hole extraction. No p‐type doping is used in the device. Charge transfer from the ITO and the n‐type absorber to the interface states between the ITO and the top MgCdTe barrier results in a Fermi level located near the valence band edge of the CdTe layer. The charged interface acts as an effective “p‐region", resulting in a built‐in voltage (Vbi) up to 1.01 V. A model is proposed to predict the relationship between Mg composition in the barrier layer and the corresponding Vbi, which is in agreement with experimental results obtained from capacitance–voltage (C–V) measurements. X‐ray photoelectron spectroscopy (XPS) measurements on samples having a MgCdTe top barrier layer with different Mg compositions confirm the correlation between the interface Fermi‐level position and the observed Vbi. This approach of utilizing interface states to engineer the Fermi‐level position opens up a new pathway to overcome the fundamental dopability limitations in many semiconductors.

Orthorhombic ITO epitaxially stabilized on a perovskite oxide substrate

Doped indium oxides, such as indium tin oxide (ITO), have been used as transparent conducting materials and have recently attracted increasing interest as thin-film channel materials for high-performance field-effect transistors. In numerous studies on crystalline ITO, stable bixbyite-type (cubic) and metastable corundum-type (rhombohedral) phases have been investigated. Here, we demonstrate an epitaxial stabilization of the ITO polytype having Rh2O3-II-type (space group: Pbna) orthorhombic structure using an orthorhombic perovskite oxide (110) DyScO3 (DSO) substrate. Distorted-orthorhombic ITO (o-ITO) films could be epitaxially grown at substrate temperatures of approximately 350 °C. The epitaxial relationships were determined to be ITO[100]//DSO[100] and ITO[001]//DSO[001], whereas the [010] of ITO was slightly inclined relative to that of DSO because of the strain effect. The transport properties of a distorted o-ITO film were better than those of a bixbyite-type ITO film grown on yttria-stabilized zirconia substrate, indicating that o-ITO has a potential of high-performance oxide semiconductor contributing to future electronics.

Ultra-broadband and optically transparent metamaterial-based absorber for electromagnetic absorption/shielding

In this paper, an optically transparent ultra-broadband metamaterial-based microwave absorber using indium tin oxide (ITO) deposited on glasses is proposed. The proposed structure integrates two glasses: the upper one is a glass substrate and the lower one is a glass coated with a hybrid metamaterial structure and a grid mesh ground using ITO film. Owing to the multi-resonances of the metamaterial and the impedance matching of the upper glass, the proposed structure obtains an ultra-broadband absorption covering 4.0–17.0 GHz (a relative bandwidth of 123.8%) with over 90% absorptivity. The structure is compact without air gap and the thickness is ∼0.093 times the upper-cutoff wavelength. The physical mechanism is analyzed using equivalent circuit and surface current distributions. Moreover, a grid mesh ground is first proposed to enhance the visible transparency to 74.69% and ensure a low microwave transmission simultaneously. A prototype is fabricated and measured, and the experiments and simulations are in good agreement. The design yields the advantages of ultra-broadband, high light transmittance, and compact, making it suitable for transparent electromagnetic absorption and shielding devices.

Applying a Nanoantenna Array on Metal To Improve the Efficiency of Phosphorescent OLEDs at High Luminance.

Phosphorescent organic light-emitting diodes (OLEDs) are suitable for display and lighting applications due to their superior luminance and efficiency. However, the strong efficiency roll-off severely hinders their potential applications in transparent displays, virtual reality, and other high-luminance-demanding fields, which is mainly attributed to severe triplet-triplet annihilation (TTA) and triplet-polaron quenching (TPQ). In this study, by employing a thin Ag anode close to the phosphorescent emitter, a Purcell factor over 5 has been achieved, nearly triple that of a conventional indium tin oxide (ITO)-based device. This enhancement significantly accelerates the exciton decay rate and reduces exciton concentration, thereby considerably lowering the incidence of TTA and TPQ. Meanwhile, such devices are capable of nearly eliminating waveguide modes, with over 77% of the energy being coupled into a surface plasmon polariton (SPP). A nanoantenna array on metal (NAoM), situated on the exterior surface of the thin Ag anode, efficiently extracts the SPP when the plasmonic antenna modes resonate with the gap modes within the NAoM. This configuration yields an efficiency enhancement of 100% at 40,000 cd/m2 compared to conventional phosphorescent devices with similar structures, providing a promising avenue for high-luminance phosphorescent OLED.

Exploring the impact of variable sputtering power on the morphological, optoelectronic, and thermoelectric properties of Fe-ITO thin films

Abstract This study employs RF magnetron sputtering to prepare and pure thin films of indium tin oxide (ITO), exploring both its pure form and its augmentation with iron (Fe) doping. The influence of Fe on these films was thoroughly scrutinized using diverse characterization approaches, including thermoelectric evaluations, X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy, and Hall measurements. XRD confirmed the cubic crystal structure, while SEM imaging revealed a distinctive granular like arrangement. The optical results (Tauc plot) revealed a narrowed bandgap (3.80 eV–3.67 eV) and diminished optical transmission in the visible spectrum owing to Fe doping. Electrical analysis revealed enhanced carrier availability, yielding a significant drop in thin film resistivity to 4.7 × 10−5 Ω cm at an Fe concentration of 50 W. However, a increased Fe content leads to increased carrier density and resistivity. The mobility decreases, and the Seebeck value diminishes with increasing carrier concentration and Fe content. Remarkably, at 20 W Fe power, the thermoelectric power factor peaks at 0.73, aligning with a resistivity of 7.18 × 10−5 Ω cm. These compelling findings, spanning the optical, structural, electrical, and thermal dimensions, emphasize the prospective utility of these materials in thermoelectric and photovoltaic systems.

Research on the optimization of electrical properties for low-temperature sintered indium tin oxide slurry

Research on the optimization of electrical properties for low-temperature sintered indium tin oxide slurry

Development of LiFx/Al2O3/ITO Multilayer Antireflection Coatings for Reflectance Reduction in Silicon Heterojunction Solar Cells

This study focuses on the optimization of antireflection coatings (ARCs) to enhance the performance of silicon heterojunction (SHJ) solar cells. SHJ solar cells face a significant challenge in achieving their theoretical efficiency limits due to light reflection at the air–cell interface. This reflection reduces photon absorption, which limits photocurrent generation and hinders the widespread adoption of SHJ technology. To address this, the optimization of ARCs using single, double, and triple‐layer designs with a graded refractive index material as the active layer is investigated. The optimization process is simulated by calculating the layer thicknesses using OPAL2 software and validated through experimental deposition. The results demonstrate that a triple‐layer ARC structure consisting of 80/50/95 nm of indium tin oxide (ITO), aluminum oxide (Al2O3), and lithium fluoride (LiFx) significantly improves SHJ performance. This configuration leads to a 1.04 mA cm−2 increase in short‐circuit current density (Jsc), reaching 39.85 mA cm−2, and an efficiency of 21.62%, compared to a single‐layer ARC. This study presents a promising solution to improve SHJ solar cell efficiency by reducing reflection losses and optimizing optical properties, contributing to the advancement of SHJ technology and facilitating the development of more efficient and cost‐effective photovoltaic systems for sustainable energy transition.

Thermal insensitivity of an ENZ-ITO clad, hollow-core micro-ring resonator

We report on the experimental demonstration of temperature insensitivity in an epsilon-near-zero (ENZ) indium-tin-oxide (ITO) cladded, hollow-core micro-ring resonator. The permittivity of the ITO cladding was engineered to a near zero value at 1550 nm wavelength to support index guiding in the air-ITO waveguide around the C band. The air-ITO ring-resonator structure was designed using numerical simulations to support whispering gallery modes. The hollow-core microresonator structure was fabricated using two-photon lithography to 3D print a sacrificial scaffold. Guided resonator modes were observed by coupling tunable laser light to the ring resonator using a tapered fiber. The demonstrated hollow-core microresonator exhibits athermal behavior and has a temperature dependent wavelength shift of 1 pm/°C.

Fabricating Silver Nanowire–IZO Composite Transparent Conducting Electrodes at Roll-to-Roll Speed for Perovskite Solar Cells

This study addresses the challenges of efficient, large-scale production of flexible transparent conducting electrodes (TCEs). We fabricate TCEs on polyethylene terephthalate (PET) substrates using a high-speed roll-to-roll (R2R) compatible method that combines gravure printing and photonic curing. The hybrid TCEs consist of Ag metal bus lines (Ag MBLs) coated with silver nanowires (AgNWs) and indium zinc oxide (IZO) layers. All materials are solutions deposited at speeds exceeding 10 m/min using gravure printing. We conduct a systematic study to optimize coating parameters and tune solvent composition to achieve a uniform AgNW network. The entire stack undergoes photonic curing, a low-energy annealing method that can be completed at high speeds and will not damage the plastic substrates. The resulting hybrid TCEs exhibit a transmittance of 92% averaged from 400 nm to 1100 nm and a sheet resistance of 11 Ω/sq. Mechanical durability is tested by bending the hybrid TCEs to a strain of 1% for 2000 cycles. The results show a minimal increase (<5%) in resistance. The high-throughput potential is established by showing that each hybrid TCE fabrication step can be completed at 30 m/min. We further fabricate methylammonium lead iodide solar cells to demonstrate the practical use of these TCEs, achieving an average power conversion efficiency (PCE) of 13%. The high-performance hybrid TCEs produced using R2R-compatible processes show potential as a viable choice for replacing vacuum-deposited indium tin oxide films on PET.

A Transparent and Flexible Absorber for Electromagnetic Interference Suppression, Designed for 5G Communication and Sub-6G Applications

As 5G technology rapidly advances, the extension of spectrum into millimeter-wave bands enables higher data speeds and reduced latency. However, this frequency expansion introduces significant electromagnetic interference (EMI) issues, particularly in environments with dense equipment and base stations. To tackle these challenges, this paper presents a multilayer transparent ultra-wideband microwave absorber (MA) using indium tin oxide (ITO) that operates between 4 and 26 GHz. This optimized MA design successfully achieves absorption from 4.07 to 25.07 GHz, encompassing both the 5G Sub-6 GHz and n258 bands, with a relative bandwidth of 144% and a minimal thickness of 0.129λL (where λL is the free-space wavelength at the lowest cutoff frequency). For TE and TM polarization with incidence angles ranging from 0° to 45°, the MA demonstrates exceptional performance, maintaining a relative bandwidth exceeding 120%. Notably, for TM polarization with incidence angles between 60° and 70°, the MA can sustain an absorption capacity with a relative bandwidth greater than 100%. By integrating the principles of impedance matching, surface current theory, and equivalent circuit simulation fitting, the absorption mechanism is further analyzed, thereby confirming the reliability of the design. This design offers exceptional wideband absorption, optical transparency, and wide-angle incidence characteristics, demonstrating great potential for applications in electromagnetic stealth, EMI suppression, and electromagnetic compatibility (EMC) in 5G communications.

Tailoring Morphology and Wetting Behavior of Films of Ionic Liquid Mixtures.

Extensive research has focused on films formed by pure ionic liquids (ILs). However, growing interest in IL mixtures and their synergistic properties presents new opportunities for targeted applications and fundamental scientific investigations. This study explores the morphology of films composed of mixtures of two ILs, [C2C1im][OTf] and [C8C1im][OTf], co-deposited via physical vapor deposition (PVD)/vacuum thermal evaporation. The primary objective was understanding how varying the IL ratio influences droplet formation, surface coverage, and overall film structure. Thin-film growth was examined on glass substrates coated with indium tin oxide (ITO) and ITO/glass surfaces coated with metallic films (Au and Ag). Film morphology was characterized using optical and high-resolution scanning electron microscopy (SEM), while elemental composition was analyzed via X-ray photoelectron spectroscopy (XPS). The results show that IL mixture morphology is strongly influenced by both IL composition and substrate type. Increasing [C8C1im][OTf] content led to larger microstructures due to improved wetting, particularly on Au surfaces, resulting in nearly fully coalesced films. Metallic surfaces near ITO significantly impacted droplet behavior, with ILs exhibiting a strong affinity for metals, especially when the long-chain IL dominated the mixture. The IL-assisted crystallization of rubrene, a high-performance organic semiconductor (OSC) that typically exhibits poor crystallinity when deposited via PVD, highlights the potential of IL mixtures to enhance organic film quality. X-ray diffraction (XRD) confirmed that [C2C1im][OTf] and [C8C1im][OTf] mixtures significantly improved rubrene crystallinity, demonstrating their potential to create an optimal environment for OSC solubility and crystallization.