Spin Coating Research Articles

Preparation of V2O5-Ink for the Fabrication of V2O5 Thin Films by the Spin Coating Method.

This article reports the preparation of V2O5 ink via a novel chemical route. The prepared V2O5 ink has been spin coated for the synthesis of V2O5 thin films on glass substrates. The synthesized V2O5 thin films were annealed at 300-400 °C in air and characterized by different techniques. The X-ray diffraction data reveal the phase pure V2O5 compound with polycrystalline nature. The scanning electron microscopy micrographs unravel that the V2O5 thin films are smooth with few nanoflakes presented on the surfaces. An optical study reveals that transmittance and bandgap of the V2O5 thin films decrease with annealing temperature. The bandgap of the films varies in the range of 2.8-2.9 eV. These findings have opened a new avenue for the preparation of metal oxide ink. The prepared V2O5 ink is promising for the manufacture of low-cost V2O5-based photoelectrochemical cells.

Sol-Gel Spin Coating Synthesis and Characterization of Cadmium Zinc Phosphate Thin Films: Structural, Optical, and Electrical Properties

This study successfully implemented the sol-gel and spin coating technique to grow cadmium zinc phosphate cadmium zinc phosphate (CZP) thin films on a glass substrate and p-Si wafer. Structural and morphological analyses were conducted via X-ray diffraction (XRD) and field-emission scanning electron microscopy (SEM). Additionally, the films’ linear and nonlinear optical properties, encompassing absorbance performance, energy gap, refractive index, dielectric, conductivity, and electronegativity, were systematically studied through UV–vis spectroscopy. XRD analysis uncovers the zinc ions substitution by cadmium ions in zinc phosphate’s unit cell, generating oxygen vacancies crucial for maintaining charge neutrality. SEM images then showcase the intricate and organized nano CZP framework. Shifting to optical studies, CZP film analysis spanning 190–2500 nm reveals an indirect energy band gap of 2.92 eV. Transitioning to electrical characteristics, the CZP/p-Si junction undergoes dark mode I-V-T analysis, elucidating the ideality factor, series resistance, and barrier height.

Investigation of Spintronic Properties of Transition Metal Doped ZnO Thin Films Produced by Sol-Gel Spin Coating

Transition metal-doped diluted semiconductor materials have attracted significant interest in spintronic applications. In order to investigate the structural, optical, electrochemical, and magnetic properties of these diluted magnetic semiconductors, transition metal-doped ZnO thin films were successfully produced at room temperature using a low-cost sol-gel spin coating technique with the same molar ratios. XRD analyses revealed that all samples adopted the crystal structure of ZnO. Optical measurements indicated high transparency in the visible region for all samples, while electrical measurements confirmed that all samples were n-type semiconductors. Finally, magnetic measurements showed that pure ZnO and Al-doped ZnO exhibited diamagnetic behavior, while Ni and Co doped ZnO displayed magnetic behavior. These results show that Co and Ni-doped ZnO films can be used as diluted magnetic semiconductor materials in spintronic applications.

Evaluation of Mechanical and Elemental Properties of Bioceramic-Coated Orthodontic Brackets and Enamel Surface.

The aim is to coat orthodontic brackets with two different bioactive materials and to compare the mechanical and morphological properties of coated brackets and tooth surfaces. A total of 120 stainless steel brackets were divided equally into three groups, that is, the uncoated brackets and nanohydroxyapatite (nHA)-coated, and nanobioactive glass (nBG)-coated brackets using a spin coater machine. The brackets were bonded on the enamel surface and underwent remineralization/demineralization cycles for days 1, 7, 14, and 30. At each time interval, the bond strength of the brackets was assessed using mechanical loading. An optical and scanning electron microscope (SEM) were used for surface evaluation, and the adhesive remanent index (ARI) values were obtained and quantified. One-way analysis of variance using Tukey's test was used to compare the differences among the groups. A uniform distribution of nanoparticles occurred on the surfaces of brackets. The shear bond strength (SBS) showed no significant differences in any tested groups on days 1, 7, and 14. However, control and nBG showed a significant difference from nHA at day 30. On days 7, 14, and 30, the nHA group showed the highest SBS values among the groups. For ARI, most samples showed an adhesive nature of failure at the enamel-brackets interface. The images confirmed the presence of coated particles on brackets and remnants of adhesives after SBS. This study confirmed that the nHA- and nBG-coated brackets have a high potential for application in orthodontics regarding structural and mechanical properties.

Effect of Spin Speed on the Physical Characteristics of CuO Films Synthesized by Sol–Gel Spin Coating for H2S Gas Sensing

Effect of Spin Speed on the Physical Characteristics of CuO Films Synthesized by Sol–Gel Spin Coating for H2S Gas Sensing

High Responsivity of Sol-gel TiO2NPs/Si Photodetectors Deposited by Spin Coating Method

High Responsivity of Sol-gel TiO2NPs/Si Photodetectors Deposited by Spin Coating Method

Sustainable nonvolatile resistive switching memory using chitosan/MEH-PPV polymer blend

Functionalization of materials is crucial in modern science and technology, particularly biodegradable ones, to reduce the increasing electronic waste affecting the planet. In this study, the electronic behavior of chitosan was modified by incorporating the MEH-PPV polymer. Four composites with weight percentages of 0.25 (S1), 0.5 (S2), 1 (S3), and 1.5 (S4) wt% were prepared. The optical energy bandgap of these composites ranged from 2.0 to 3.02 eV. These materials were studied for their potential use in resistive switching memory (ReRAM). Two device classes: Class A (drop cast) and Class B (spin coat), were developed. The Class A S4-based device exhibited memory behavior with a minimum of 20 write/erase cycles. The other devices in this class demonstrated poor conductivity and data noise. Class B devices exhibited no switching, except for the S3-based device. Our research suggests that the thickness of class A devices has a notable impact on their performance limitations. The study shows that the chitosan:MEH-PPV blend holds promise for environmentally friendly ReRAMs, and optimizing the thickness and weight ratio can significantly improve device performance.

Enhanced photodiode performance: Au/boron-dipyrromethene/n-Si/Ag structure unveiling high photosensitivity and efficiency

In this study, the classical boron-dipyrromethene (4,4- difuoro-4-borata-3a-azonia-4a-aza-s-indacene, BODIPY) unit (C1), its halogenated derivative (C2), and disytryl derivative (C3), which are known for their absorption properties in the near-infrared (NIR) region, were synthesized. Chemical and photophysical investigations were carried out to reveal the complex features of the molecules using a range of spectroscopic techniques and their energies were calculated by Density Functional Theory (DFT) with the same basis set. The BODIPY thin films were coated on n-Si substrates using a spin coater to examine the effect of interlayer on photodiode/photovoltaic properties and Au/BODIPY (C1, C2, C3)/n-Si/Ag photodiodes having rectifying behavior were fabricated. The thermionic emission theory (TET) and modified Norde’s functions were utilized to determine the rectification ratio, ideality factor, series resistance, and barrier height values of diodes. The values of barrier height, ideality factor, and rectification ratio at ± 2 V were calculated as 0.81 eV, 1.83 and 2.47x103 for the Au/C1/n-Si/Ag diode, 0.83 eV, 1.63, and 7.06 x103 for the Au/C2/n-Si/Ag diode and 0.84 eV, 1.51 and 2.14x104 for the Au/C3/n-Si/Ag diode in the dark from the TET, respectively. The values of FF (%) and efficiency were calculated as 38 and 1.51 for the Au/C1/n-Si/Ag diode, 47 and 2.03 for the Au/C2/n-Si/Ag diode, and 56 and 3.68 for the Au/C3/n-Si/Ag diode under 100 mW/cm2 illumination, respectively. With remarkable electrical properties, the Au/C3/n-Si/Ag photodiode stood out among the others, performing better in both dark and light conditions. Therefore, the produced diodes based on the BODIPY thin film can be employed as photodiodes/photovoltaics in optoelectronic applications.

Optimizing Methylammonium Lead Iodide Perovskite Synthesis for Solar Cells via Two-step Spin Coating with Mixed Solvents

Optimizing Methylammonium Lead Iodide Perovskite Synthesis for Solar Cells via Two-step Spin Coating with Mixed Solvents

Structural and Electronic Impact on Various Substrates of TiO2 Thin Film Using Sol-Gel Spin Coating Method

Structural and Electronic Impact on Various Substrates of TiO2 Thin Film Using Sol-Gel Spin Coating Method

Synthesis of ZnO/CZTS Hetero-Structure Junction by Sol–Gel Spin Coating Technique

Pertaining to the optimal band alignment of ZnO and CZTS, the heterostructure was fabricated with CZTS as the absorber layer and ZnO being the buffer layer coated on the FTO glass for photovoltaic application. Both the layers were deposited by using sol–gel spin coating technique. The results revealed the polycrystalline nature of both ZnO and CZTS films with distinct phase formations, with ZnO exhibiting prominent diffraction peaks at 31.77, 34.31, 36.20, 47.47, and 56.59° corresponding to (100), (002), (101), (102), and (110) planes, while CZTS showed diffraction peaks at (112), (220), and (312) planes. ZnO thin films demonstrated high optical transmittance (∼90%) and exhibited a wide band gap of 3.24 eV, while CZTS demonstrated a band gap of 1.44 eV. AFM images showed smooth surfaces with favorable topography for both films. Hall effect measurements indicated differences in electrical properties of the two films. Raman spectroscopy revealed vibrational energy patterns in both films. Additionally, current–voltage (I-V) characteristics revealed the electrical behavior of the ZnO/CZTS heterojunction, shedding light on its diode characteristics under both dark and illuminated conditions. With CZTS’s ideal band gap of 1.44 eV, sunlight is easily absorbed, and ZnO’s high electron mobility makes it an effective layer for electron transport. As a result, power conversion efficiency can be improved.

Dielectric Properties and Electrical Characteristics of a Triphenylamine Thin Film Deposited onto a Silicon Substrate via Spin Coating

Dielectric Properties and Electrical Characteristics of a Triphenylamine Thin Film Deposited onto a Silicon Substrate via Spin Coating

Cu-Doped TiO2 Thin Films by Spin Coating: Investigation of Structural and Optical Properties

Cu-doped TiO2 films were synthesized directly on FTO glass with a spin coating method. With a variation in copper amount, samples were prepared with 0%, 1%, 2%, 4% and 8% of dopant concentrations. Morphological and structural characterization of undoped and Cu-doped TiO2 samples were investigated and the obtained results showed the small, spherical shapes of the nanoparticles forming a thin film on top of FTO glass and their preferred orientation of TiO2 anatase (101), which is the same for each sample. However, this peak exhibited a slight shift for the 2% sample, related to the inflation of the microstrain compared to the other samples. For the optical properties, the 4% sample displayed the highest transmittance whereas the 2% sample exhibited the lowest band gap energy of 2.96 eV. Moreover, the PL intensity seems to be at its highest for the 2% sample due to the present peaking defects in the structure, whereas the 8% sample shows a whole new signal that is related to copper oxide. These properties make this material a potential candidate to perform as an electron transport layer (ETL) in solar cells and enhance their power conversion efficiency.

Spin coating on a budget: A 3D-Printed all-mechanical alternative for cost-effective thin-film deposition

Spin coating stands out as the most employed thin-film deposition technique across a variety of scientific fields. Particularly in the past two decades, spin coaters have become increasingly popular due to the emergence of solution-processed semiconductors such as quantum dots and perovskites. However, acquiring commercial spin coaters from reputable suppliers remains a significant financial burden for many laboratories, particularly for smaller research or educational facilities. Prompted by the simple mechanical principles of the device, in this work, we present a 3D-printed analogue that can be printed and assembled in under 10 h and costs less than 5 euros per device. The operating principle is fully mechanical since the rotating motion is induced by gas flow. It does not require any additional components such as DC motors, motor drivers, circuitry or software and thus it can be fully operational off the grid. Additionally, the gas flow generates a purging effect that was found to be rather advantageous for film formation. To prove the effectiveness of this device, we have employed it to fabricate planar thin-film antimony sulfide (Sb2S3) solar cells. The optoelectronic characteristics of solar cells revealed noteworthy improvements, particularly in terms of repeatability, when compared to those fabricated with a commercial spin coater.

Impact of Graphene oxide (GO) and reduced Graphene Oxide (rGO) on the TiO2 thin film composite (TiO2: GO/ rGO) photoanodes

Graphene and its derivatives have several advantages such as large surface area, great chemical stability, high transmittance, and good electrical conductivity, which are the fundamental qualities required by photovoltaic industries. GO and rGO are mixed in various proportions ranging 0 wt.% - 15 wt.% to spin coat TiO2: GO/rGO composite thin films. The effect of graphene oxide and reduced graphene oxide on the performance the TiO2 based composite photoanodes are obtained. A tetragonal anatase phase of TiO2 was confirmed by the XRD analysis. The calculated crystallite size decreases with lower concentrations of GO and rGO but starts to increase for higher concentrations. The spectrophotometer studies have confirmed that the optical bandgap of pure TiO2 films is decreased on doping with GO and rGO. The SEM analysis have confirmed that the surface is tightly packed with the uniformly distributed grains, and they are very compact.

The development of low-cost spin coater with wireless IoT control for thin film deposition

A low-cost spin coater with a wireless remote system that can deposit thin films of uniform thickness and quality at a significantly lower cost than traditional methods. The system consists of three main parts, a motorized spindle, a spin-coating head, and a control system connected to the network. The mechanical design on the mechanical part, spin coater system design with ESP32, and implementation of wireless control through visual basic. The network-enabled control system allows for real-time monitoring and adjustment of the deposition process, which can improve efficiency and reproducibility. This low-cost spin coating system represents a promising solution for organizations seeking to access thin film deposition technology at a fraction of the cost of traditional systems. By integrating wireless IoT control into low-cost spin coaters, the impact of this technology on coating uniformity will provide valuable insights for future advancements in this field.

3D Printing of Optical Lenses Assisted by Precision Spin Coating

AbstractThough 3D printing shows potential in fabricating complex optical components rapidly, its poor surface quality and dimensional accuracy render it unqualified for industrial optics applications. The layer steps in the building direction and the pixelated steps on each layer's contour result in inevitable microscale defects on the 3D‐printed surface, far away from the nanoscale roughness required for optics. This paper reports a customized vat photopolymerization‐based lens printing process, integrating unfocused image projection and precision spin coating to solve lateral and vertical stair‐stepping defects. A precision aspherical lens with less than 1 nm surface roughness and 1 µm profile accuracy is demonstrated. The 3D‐printed convex lens achieves a maximum MTF resolution of 347.7 lp mm−1. A mathematical model is established to predict and control the spin coating process on 3D‐printed surfaces precisely. Leveraging this low‐cost yet highly robust and repeatable 3D printing process, the precision fabrication of multi‐scale spherical, aspherical, and axicon lenses are showcased with sizes ranging from 3 to 70 mm using high clear photocuring resins. Additionally, molds are also printed to form multi‐scale PDMS‐based lenses.

Fabrication and Properties of Bi2S3 Nanowire Thin Film Solar Cells by Spin Coating with Varying Sulfur Concentrations in the Precursor

We conducted a simple solution-based method to fabricate Bi2S3 nanowire thin film solar cells by spin coating with varying sulfur-to-bismuth ratios. Spherical nanoparticles were observed in the thin film with low-concentration sulfur solution, with these nanoparticles gradually changing to nanorods. Finally, nanowires of Bi2S3 were observed in the thin film with a high sulfur concentration in solution. The band gap gradually decreased with the increase in sulfur concentration. The solar cell performance was significantly improved with the nanowire structure. During film fabrication, sulfur vacancy defects appeared primarily because of high annealing temperatures. These defects were somewhat reduced by the high concentration of sulfur in the solution, supported by the energy-dispersive x-ray spectroscopy (EDS) results. The elemental chemical composition of Bi2S3 material showed an increase in the sulfur-to-bismuth ratio, reaching saturation at almost 0.9. In this work, we systematically observed the effect on the optical properties, surface morphology, and photovoltaic properties by changing the concentration of sulfur in the precursor. The nanowire structure with a high concentration of sulfur in the solution is a promising way to improve the Bi2S3 thin film solar cell.

Insights into the Physical Characteristics of Spin Coating Films of Organometallic Materials Based on Phthalocyanine with Nickel, Copper, Manganese and Silicon

Insights into the Physical Characteristics of Spin Coating Films of Organometallic Materials Based on Phthalocyanine with Nickel, Copper, Manganese and Silicon

Study on multifunctional resistive switching and UV light detection characteristics in p-PEDOT:PSS/i-BFO/n-ZnO hybrid structures

The present research work based on the newly prepared organic-inorganic hybrid heterostructure will be exploited to develop a multifunctional device including non-volatile resistance switching memory devices, and ultraviolet (UV) light detection behavior for the first time based on p-PEDOT:PSS/i-BFO/n-ZnO junctions. Using a spray pyrolysis technique, n-type zinc oxide (ZnO) and i-type bismuth ferrite (BiFeO3) thin film layers were prepared on the clean glass substrates at temperature 673 K. Using a spin coater method, the p-PEDOT:PSS were grown upon a bismuth ferrite (BiFeO3) thin film with a constant spin velocity of 2000 rpm and heated at 363 K. The current (I)–voltage (V), photoresponse characteristics and resistive switching (RS) behavior of the fabricated p-PEDOT:PSS/i-BFO/n-ZnO hybrid devices were carried out. The device shows high photoresponsivity (R) of 0.001 285 A W−1 and fast photoresponse switching speed with the measured rise and fall time of 493 and 970 ms respectively. Based on the electrical properties, a conductive filament formation/rupture mechanism is proposed to explain the observed RS characteristics.