Indium Tin Oxide Substrates Research Articles

Suppressing interfacial nonradiative recombination by alkali hydroxides for efficient blue perovskite light-emitting diodes

Blue perovskite light-emitting diodes (PeLEDs) provide unlimited possibility in the field of optoelectronic devices due to their excellent characteristics. However, the widely used hole-transport material, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), has strong acidity and poor conductivity which deteriorate the efficiency and stability of perovskite devices. In this work, we modified PEDOT:PSS layer using alkalis, LiOH, NaOH, and KOH, to address these issues. Our findings indicated that the indium defect from indium tin oxide substrate was passivated after the introduction of LiOH, which resulted in the suppression of nonradiative recombination. In addition, the conductivity was improved owing to the increased phase separation of PEDOT:PSS. Taking advantage of optimized interface, the small-n phases of quasi-two-dimensional (quasi-2D) perovskite films were redistributed in quantities and dimensions. As results of these improvements, blue PeLEDs possessed the external quantum efficiencies of 5.95 % and an extended half-lifetime with emission-light wavelength of 473 nm. These findings offer an effective strategy to achieve highly efficient blue light-emitting diode.

Machine Learning Aided Optimization of P1 Laser Scribing Process on Indium Tin Oxide Substrates

Present study employes a picosecond laser (532 nm) for selective P1 laser scribing on the indium tin oxide (ITO) layer and subsequent fine‐tuning of P1 scribing conditions with machine learning (ML) techniques. Initially, the scribing is performed by varying different laser parameters and further evaluate them via an optical microscope and two probe resistivity measurements. The corresponding scribing width and sheet resistance data are used as input databases for ML analysis. The classification and regression tree (CART)‐based ML analysis revealed that median pulse energy <5.7 μJ insufficient to separate the adjacent scribing regions. While pulse energy >5.7 μJ, APL > 35%, LSO > 46%, and processing speed ≥1250 mm s−1 gives ≥16 μm of scribing width. Further, the decision tree (DT) analysis showed that pulse energy of ≥8.1 μJ, and LSO ≥ 37% are required for electrically isolated lines. The feature importance score suggests that laser fluence and pulse energy determined the scribing width, whereas electrical isolation strongly depends on LSO and processing speed. Finally, the ML achieved conditions experimentally validated and reassessed via scanning electron microscope, and atomic force microscopy aligns well with optical microscope measurements.

Electropolymerization of Preferred-Oriented Conjugated Microporous Polymer Films for Enhanced Fluorescent Sensing.

High-quality conjugated microporous polymer (CMP) films with orientation and controlled structure are extremely desired for applications. Here, we report the effective construction of CMP 3D composite films (pZn/PTPCz) with a controlled porosity structure and preferred orientation using the template-assisted electropolymerization (EP) approach for the first time. The structure of pZn/PTPCz composite thin films and nitrophenol sensing performance were thoroughly studied. When compared to the control CMP film made on flat indium tin oxide (ITO) substrates, the as-prepared pZn/PTPCz composite films showed significantly enhanced fluorescent intensity and much better sensing performance for the model explosive. This was attributed to the metal-enhanced fluorescence (MEF) of porous nanostructured zinc (pZn) and the additional macroporosity of the pZn/PTPCz composite films. This work provides a feasible approach for creating oriented 3D CMP-based thin films for advanced applications.

Chemisorption-Induced Robust and Homogeneous Tungsten Disulfide Interlayer Enables Stable PEDOT-Free Organic Solar Cells with Over 19% Efficiency.

Construction of a high-quality charge transport layer (CTL) with intimate contact with the substrate via tailored interface engineering is crucial to increase the overall charge transfer kinetics and stability for a bulk-heterojunction (BHJ) organic solar cell (OSC). Here, we demonstrate a surface chemistry strategy to achieve a homogeneous composite hole transport layer (C-HTL) with robust substrate contact by self-assembling two-dimensional tungsten disulfide (WS2) nanosheets on a thin molybdenum oxide (MoO3) film-evaporated indium tin oxide (ITO) substrate. It is found that over such a well-defined C-HTL, WS2 is homogeneously tethered on the ITO/MoO3 substrate stemming from the strong electronic coupling interaction between the building blocks, which enables a favorable interfacial configuration in terms of uniformity. As a result, the D18:L8-BO-based OSC with C-HTL exhibits a power conversion efficiency (PCE) of 19.23%, an 11% improvement over the WS2-based control device, and the highest efficiency among single-junction PEDOT-free binary BHJ OSCs.

Numerical studies of manipulation and separation of microparticles in ODEP-based microfluidic chips.

A novel optical-induced dielectrophoresis (ODEP) method employing a pressure-driven flow for the continuous separation of microparticles is presented in this study. By applying alternate current electric field on conductive indium tin oxide substrate and projecting the light geometry into the photoconductive layer, an inhomogeneous electric field is locally induced. The particles experience the dielectrophoretic force when passing through the lighting area, where the strongest electrical field gradient exists. By optimizing the structure of the lighting pattern, a stronger nonuniform electric field gradient is generated which predicts the separation of 1 and 3µm polystyrene particles. Moreover, the effects of key parameters, including the light pattern geometry, applied voltage, and flow rate, were investigated in this study, leading to the successful sorting of 700nm and 1µm particles. To further examine the separation sensitivity and practicability of the proposed ODEP microfluidic method, the isolation of two different types of circulating tumor cells from T-cells and red blood cells are demonstrated, providing a novel method for the manipulation and separation of microparticles and nanoparticles.

Carbon-Induced Changes in the Morphology and Wetting Behavior of Ionic Liquids on the Mesoscale.

Thin films of ionic liquids (ILs) have gained significant attention due to their unique properties and broad applications. Extensive research has focused on studying the influence of ILs' chemical composition and substrate characteristics on the structure and morphology of IL films at the nano- and mesoscopic scales. This study explores the impact of carbon-coated surfaces on the morphology and wetting behavior of a series of alkylimidazolium-based ILs. Specifically, this work investigates the effect of carbon coating on the morphology and wetting behavior of short-chain ([C2C1im][NTf2] and [C2C1im][OTf]) and long-chain ([C8C1im][NTf2] and [C8C1im][OTf]) ILs deposited on indium tin oxide (ITO), silver (Ag), and gold (Au) substrates. A reproducible vapor deposition methodology was utilized for the deposition process. High-resolution scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy were used to analyze the morphological and structural characteristics of the substrates and obtained IL films. The experimental data revealed that the IL films deposited on carbon-coated Au substrates showed minor changes in their morphology compared to that of the films deposited on clean Au surfaces. However, the presence of carbon coatings on the ITO and Ag surfaces led to significant morphological alterations in the IL films. Specifically, for short-chain ILs, the carbon film surface induced 2D growth of the IL film, followed by subsequent island growth. In contrast, for long-chain ILs deposited on carbon surfaces, layer-by-layer growth occurred without island formation, resulting in highly uniform and coalesced IL films. The extent of morphological changes observed in the IL films was found to be influenced by two crucial factors: the thickness of the carbon film on the substrate surface and the amount of IL deposition.

Nonaqueous Oxidation in DNA Microarray Synthesis Improves the Oligonucleotide Quality and Preserves Surface Integrity on Gold and Indium Tin Oxide Substrates.

Nucleic acids attached to electrically conductive surfaces are very frequently used platforms for sensing and analyte detection as well as for imaging. Synthesizing DNA on these uncommon substrates and preserving the conductive layer is challenging as this coating tends to be damaged by the repeated use of iodine and water, which is the standard oxidizing medium following phosphoramidite coupling. Here, we thoroughly investigate the use of camphorsulfonyl oxaziridine (CSO), a nonaqueous alternative to I2/H2O, for the synthesis of DNA microarrays in situ. We find that CSO performs equally well in producing high hybridization signals on glass microscope slides, and CSO also protects the conductive layer on gold and indium tin oxide (ITO)-coated slides. DNA synthesis on conductive substrates with CSO oxidation yields microarrays of quality approaching that of conventional glass with intact physicochemical properties.

Fine Tuning Ag(I)-Sb(III) Hybrid Iodides for Light Detection.

Lead-free hybrid double perovskite iodides (HDPIs) have piqued increasing research interest due to their environmental friendliness and high stability. However, such antimony-based HDPIs with strong photocurrent response are currently very limited. Here, we successfully design and construct five Ag(I)-Sb(III)-based HDPIs using two types of cyclic aliphatic amines as A-site templates. Interestingly, these Ag(I)-Sb(III) HDPIs exhibit relatively narrow band gaps, preferred orientation, and high stability after being processed into thin films on the indium tin oxide (ITO) substrate. Notably, under illuminations of a xenon lamp, all HDPIs exhibit considerable photocurrent responses, reaching a maximum difference of 17 μA·cm-2 for ASI 1, which is the highest among lead-free halogen-based organic-inorganic hybrid compounds to date. Combining the considerable photocurrents and the high stability, the optoelectronic applications of two-dimensional Ag(I)-Sb(III) HDPIs can be expected.

Electrical synaptic devices with a high recognition rate based on eco-friendly nanocomposites of a poly(methyl methacrylate) matrix embedded with graphene quantum dots for neuromorphic computing

Artificial synapse devices are currently the subjects of great attention as next-generation hardware for data processing to overcome the problem of data explosion due to the rapid advances in artificial intelligence and cloud computing technology. Nanocomposite-based devices enable unique applications and have several advantages that cannot be achieved in single material-based devices. This study presents binary electrical synapses with digital data storing and analog data processing through a nanocomposite-based active layer composed of poly(methyl methacrylate) (PMMA) with embedded chlorine-functionalized graphene quantum dots (fGQDs) on an indium tin oxide (ITO) substrate. The Al/PMMA-fGQD/ITO devices with an fGQD concentrations of 5 wt% exhibited excellent memory performance with RON/ROFF ratio of 103. Moreover, we demonstrated that our device can successfully emulate biological synaptic functions such as potentiation/depression, short-term/long-term memory, paired-pulse facilitation, learning experience, and spike-timing-dependent plasticity. Furthermore, on the basis of the synaptic behaviors of the devices, they achieved about a 90 % recognition capability when a learning algorithm was used in a single-layer neural network.

Effect of hot electron induced charge transfer generated by surface plasmon resonance on Ag@Au/ITO/PNTP systems

The present study discusses the fabrication of a bimetallic material consisting of silver nanorods and gold nanospheres (designated Ag@Au), and its surface modification with 4-nitrothiophenol (PNTP) after deposition on an indium tin oxide (ITO) glass sheet, followed by laser irradiation at various wavelengths. The results indicate that the reduction of PNTP is more complete under irradiation at 532 nm due to the surface plasmon resonance (SPR) effects of the gold and silver nanomaterials. Moreover, the surface enhanced Raman scattering (SERS) of the PNTP adsorbed on the Ag@Au/ITO is found to be significantly stronger than that of PNTP adsorbed on Ag@Au alone, due to charge transfer (CT) at the interface. In addition, the SERS enhancement effect of the PNTP molecules on the Ag@Au/ITO substrate is optimal under 532 nm laser irradiation due to the hot electron-induced CT generated by the SPR effect. Thus, the system constructed herein combines the effects of SPR and CT, thereby assisting in a further understanding of the enhancement mechanism of SERS and, hence, the further development SERS research in metal-semiconductor-molecular systems.

Sputter-cleaning modified interfacial energetic and molecular structure of DNTT thin film on ITO substrate

The effect of natural electrode contamination on interfacial energetic, structure and morphology of π-conjugated organic molecular layers were studied by depositing dinapthothienothiophene (DNTT) thin films of varying thickness on indium-tin-oxide (ITO) substrates and by using photoelectron spectroscopy, atomic force microscopy and X-ray reflectivity techniques. The DNTT thin film on unclean-ITO surface shows a smaller threshold ionization potential (by ∼0.4 eV) compared to the film on clean-ITO one. A molecule–substrate interaction, present in the DNTT/clean-ITO system, gives rise to an interfacial dipole and charge transfer, presumably through flat-lying seed-layer at the interface. On further deposition, the interfacial coverage increases, while the molecules on top of the seed-layer take different orientation (mostly edge-on) to form highly-dewetted fibrous-islands of very high-thickness but very low-coverage. Overall, the growth of DNTT film on clean-ITO surface is layer-plus-island-like or Stranski–Krastanov-type. On the other hand, the contamination layer at the DNTT/unclean-ITO interface is found to act as a spacer layer, which reduces the intimate molecule–substrate interaction and also the roughness to give rise an edge-on ordered island-like or Volmer–Weber-type film-growth with reduced hole injection barrier (by ∼0.2 eV) and better (almost double) film-coverage to make it a more efficient hole injector compared to the clean interface one.

Sol-gel synthesized RexBi1-x-O thin films for electrochemical creatinine sensing: A facile fabrication approach

The escalating predominance of renal diseases has obliged vigorous research on developing efficient and cost-effective biosensors for creatinine, an aspirant biomarker reflecting renal health. Herein, we fabricated a highly sensitive and selective Rhenium (Re)-doped Bismuth oxide (Bi2O3) (RexBi1-x-O) based enzymatic electrochemical creatinine biosensor. Various concentrations of Re (5%, 10%, and 20%) were mixed with Bi2O3 solution via facile sol-gel synthesis and deposited on an Indium Tin oxide (ITO) substrate. The detailed physicochemical and electrochemical performance of the thin film was investigated and compared at different annealing temperatures (400 °C, 500 °C, and 600 °C). The optimized RexBi1-x-O thin film (Re0.10Bi0.90-O at 500 °C annealing temperature) depicted a limit of detection (LOD) as low as 28 μM in a concentration range of 0.05 mM–2 mM with excellent selectivity. To ensure the feasibility of the proposed creatinine sensor, its sensing performance was verified in human serum contaminated with altered creatinine concentrations, which manifested a satisfactory recovery rate. Eventually, the outstanding performance of RexBi1-x-O-based enzymatic creatinine sensor indorsed it as an accountable candidate for even more complex markers detection.

Investigation on the electrocatalytic oxidation of alcohol using zinc oxide thin films deposited by pulsed electrodeposition on an indium tin oxide surface

To perform electro-catalytic oxidation of alcohols in an alkaline media, zinc oxide (ZnO) thin films were effectively deposited on indium tin oxide (ITO) substrates using the pulsed electrodeposition (PE) method in a zinc nitrate aqueous solution. Analyses of microstructural, photoelectrochemical, and optical characteristics of ZnO thin films were performed as a function of pulsed electrodeposition parameters. XRD analysis was applied to determine structural properties, and SEM and AFM analysis were used to investigate morphological characteristics. X-ray diffraction analyses revealed that the produced films were polycrystalline and had a (002) preferentially oriented, hexagonal wurtzite structure. The morphology of ZnO has improved in the direction of nanorod films, as evidenced by scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. UV transmittance data was used using Tauc's relationship to determine the film's bandgap to be 3.26 eV. The photocurrent response shows that ZnO films have high values, at 305.17 A/cm2, and good optical characteristics. The electrocatalytic oxidation of methanol was finally evaluated on the films. After being optimized in the pulsed electrodeposition mode, ZnO thin film characteristics and methanol electrocatalytic oxidation both saw substantial improvements.

Growth of Chlorine-Doped ZnO Nanorod Arrays on Different Substrates

In this study, zinc nitrate (Zn(NO3)2), hexamethylenetetramine (C6H12N4), and sodium chloride (NaCl) were employed as precursor materials to synthesize ZnO nanorod arrays on two distinct types of substrates using the hydrothermal method. We investigated how different substrates and varying chlorine concentrations influence the synthesis properties of chlorine-doped ZnO nanorod arrays. Specifically, this study aimed to explore the structural, morphological, and optical properties of the synthesized ZnO nanorod arrays. The substrates investigated were an indium tin oxide (ITO) substrate with a ZnO seed layer and an ITO substrate with a self-assembled monolayer (SAM) of molecules. The formation of the SAM involved placing a clean ITO conductive glass substrate into a high-pressure reactor, along with a vial containing 0.2 mm of octadecyltrichlorosilane. Using this process, a uniform SAM was created on the ITO substrate. The molar ratio of Zn(NO3)2, C6H12N4, and NaCl was maintained at 1:1:x, where x varied as 0, 0.1, 0.2, 0.3, and 0.4. This corresponded to NaCl volumes of 0, 2.5, 5.0, 7.5, and 10.0 mM, respectively. The crystallinity and orientation of the nanorods were assessed with their surface morphology using scanning electron microscopy (SEM). By systematically varying the chlorine concentration and substrate type, the role of these parameters was understood in tailoring the characteristics of ZnO nanorod arrays for potential applications in optoelectronic devices, sensors, and photocatalysts.

Functionalizable poly-terthiophene/Cu2O heterojunction constructed in situ for sensitive photoelectrochemical detection of long non-coding RNA markers.

A photoelectrochemical (PEC) sensor based on the poly-2,2,5,2-terthiophene (pTTh)/Cu2O heterojunction was constructed and applied for the detection of long non-coding RNA (lncRNA) TROJAN, a biomarker of triple-negative breast cancer. Cu2O and pTTh were electrodeposited in situ and sequentially onto an indium tin oxide substrate. The bandgap of the resultant type II heterojunction was measured spectroscopically and the morphology was found to effectively separate photogenerated holes from electrons. A photocurrent density as high as 250 μA cm-2 was attained, which is about three times higher than those of only pTTh or Cu2O. Owing to the close contact between pTTh and Cu2O, this PEC sensor is highly stable. Oligonucleotide probes for lncRNA can be cross-linked to carboxyl moieties of mercaptopropionic acid molecules adsorbed on pTTh/Cu2O. The desirable band structure and the high density of probe molecules collectively yielded a linear range of 0.1-10 000 pM. Our PEC sensor has been demonstrated to be amenable for detection of lncRNA markers with excellent analytical performance.

Self-assembled organic molecules with a fused aromatic ring as hole-transport layers for inverted perovskite solar cells: the effect of linkers on performance

Two D–π–A structured SAMs (FNE29 and DT-1) with different linkers are self-assembled onto the indium tin oxide (ITO) substrates as HTLs for inverted PSCs. The results indicate that the SAMs with large conjugated fused linkers have obvious advantages as HTLs because of its fast hole transfer.

Physical and chemical properties and degradation of MAPbBr3 films on transparent substrates.

To date, the potential exploitation of hybrid organic-inorganic perovskites (HOIPs) in photovoltaic technologies has been significantly hampered by their poor environmental stability. HOIP degradation can be triggered by conventional operational environments, with excessive heating and exposure to oxygen and moisture significantly reducing the performances of HOIP-based solar cells. An imperative need emerges for a thorough investigation on the impact of these factors on the HOIP stability. In this work, the degradation of methylammonium lead bromide (CH3NH3PbBr3) thin films, deposited via spin-coating on indium tin oxide (ITO) and strontium titanate (STO) substrates, was investigated by combining Raman and ultraviolet-visible (UV-Vis) absorption spectroscopy, as well as optical and fluorescence microscopy. We assessed the physical and chemical degradation of the films occurring under diverse preservation conditions, shedding light on the byproducts emerging from different degradation pathways and on the optimal HOIP preservation conditions.

An electrochemiluminescence device for visualized detection of lead in practical samples.

Lead (Pb2+) pollution poses a significant threat to human health due to its potential accumulation through the food chain. In response to this challenge, an array of electrochemiluminescence (ECL) devices has been developed for the accurate and visualized detection of trace Pb2+, achieving an ultra-low limit of detection (LOD) of 9.8 pg L-1. The device utilizes a Pb2+-specific aptamer DNA chain, modified on gold nanoparticles (AuNPs), to create an efficient ECL probe. The integration of this ECL probe into an indium tin oxide (ITO) substrate results in a Pb2+ specific array device. With the assistance of an up-response ECL imaging system, this setup enables the accurate and visualized determination of trace Pb2+, not only in standard solution containing interference ions, but also in practical samples of Lycium ruthenicum Murr., Glycyrrhiza uralensis and lake water. This work advances the visual detection of Pb2+ using ECL-based technology, demonstrating significant potential for enhancing food safety.

Boosting the hydrophobicity of eco‐friendly polyaniline coating using TiO2 and ZnO nanoparticles

This article clarifies the thin layer deposition of superhydrophobic coating using eco‐friendly polymer (polyaniline [PANI]) incorporated with TiO2 and ZnO nanoparticles on indium tin oxide substrate. Using the cyclic voltammetry method, in situ polymerization of PANI incorporated with hybrid (TiO2–ZnO) was accomplished. The morphology and hydrophobicity of electro‐deposited films were examined; the impact of deposition cycles was also investigated. The morphological structure was studied using field‐emission scanning electron microscopy and high‐resolution transmission electron microscopy. X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analysis proved the incorporation of nanoparticles into the composite matrix. Additionally, the water contact angle of the PANI composite was found to be 150.4°, and the findings reflected that (TiO2–ZnO) nanoparticles were significantly implicated in enhancing this superhydrophobicity. The surface roughness of the PANI matrix was increased when TiO2 and ZnO are added, as was shown by atomic force microscope investigation.

Zinc Oxide Nanowall Networks Growth on Indium Tin Oxide Substrates in an Oxygen Atmosphere and Magnetic Field via the Sparking Process

A zinc oxide nanowall (ZnO NW) network was grown on an indium tin oxide (ITO) surface using the sparking process at a breakdown voltage. This process involved four pairs of pure zinc wire electrodes in a flowing oxygen atmosphere, with a perpendicular magnetic field applied downward onto the ITO surface. It was observed that the cluster number density of ZnO NWs on the ITO surface decreased with an increasing number of coatings. The transmittances of the glass/ITO/ZnO NW network substrate increased again once the nanostructure was completely formed and achieved higher crystallinity.