Electrical Properties Of Films Research Articles

Design of Electrical Sheet Resistance of Thin Film Measurement System Based on GM Cryocooler in Cryogenic Temperature

The determination of the dependencies of the electrical resistivity of the thin film to temperature is of great importance both for understanding the conduction mechanism and for numerous technical applications of these films. In this work, to characterize, the electrical properties of thin films, a GM cryocooler-based automatic board temperature range electrical properties measurement system has been constructed. The system can measure multiple samples simultaneously. The cooling process was simulated using the time-discrete differencing to validate the optimized device design parameters and minimize heat losses. Furthermore, the temperature-dependent sheet resistance results were compared with the results from the physical property measurement system.

Microstructural evolution during the crystallization process of sol-gel derived PbZrO3 nanocomposite thin films

For the application of dielectric materials in energy storage, nanocomposition is one of the effective methods to improve their electric breakdown field strength. In this study, PbZrO3-Al2O3 nanocomposite films were prepared by combined thermal evaporation deposition and a sol–gel method. By changing the annealing time, the crystallization process of PbZrO3 matrix and the formation mechanism of Al2O3 nanoparticles were studied, and the microstructure evolution process of composite films was elucidated. The results indicate that before the final annealing at 700 ℃, Al atoms have diffused into the amorphous PbZrO3 film, and some fine grains of the perovskite phase have been generated at the bottom of the film. As the annealing time increases, the perovskite grains grow along the out of plane direction of the thin film to form columnar grains, and Al atoms diffuse into the perovskite phase lattice; As the annealing time further increases, Al2O3 nanoparticles began to precipitate at the interlayer interfaces of PbZrO3 coating layers, forming a layered distribution. The changes in electric properties with annealing time also demonstrate the microstructural evolution process of the composite film during annealing. Therefore, controlling annealing time is an effective means to control the microstructure and electric properties of composite films prepared by the new method for the application of energy storage.

Enhanced structural, optical and electrical properties of polycrystalline WO3 thin films achieved by aluminum nanosheets coating

Herein the effects of aluminum nanosheets on the structural, morphological, optical and electrical properties of tungsten oxide thin films are reported. Polycrystalline phase of the thermally evaporated WO3 was achieved by the pulsed laser welding technique. The polycrystalline films are then coated with Al nanosheets of thicknesses of 100 nm and 150 nm by the ion coating technique. It is observed that Al induces the domination of the hexagonal structure of WO3 over the tetragonal. Associated with the enhanced crystallinity the light absorption in the films increased by more than 60% and the energy band gap narrowed significantly. Namely the energy band gap of the as grown WO3 decreased from 3.15 eV to 2.85 eV and 2.59 eV as the Al layer thickness increased from 100 to 150 nm, respectively. It is also observed that crystalline films of WO3 exhibited lower electrical resistivity compared to films fabricated by other techniques. The temperature dependent electrical resistivity measurement was carried out in the temperature range of 310–420 K. It showed room temperature values of 2.5 ( Ω cm), 2.2 ( Ω cm) and 1.9 ( Ω cm) and impurity levels centered at 0.25 eV, 0.34 eV and 0.16 eV for uncoated and films coated with Al nanosheets of thicknesses of 100 nm and 150 nm, respectively. The enhanced crystallinity that is accompanied with narrower energy band gap and lower electrical resistivity values make crystalline WO3 films promising for optoelectronic applications.

Investigation of optical and electrical properties of TiO2, SiO2, and Ag single and multilayer thin films using spectroscopic ellipsometry and spectrophotometry methods: prepared by spin coating and DC magnetron sputtering

In this work, spectroscopic ellipsometry was used to study the optical and electrical properties of TiO2 and SiO2 thin films deposited by spin-coating at different coating rotation speeds and annealed at various temperatures. In addition, Ag thin films of different thicknesses were deposited by DC magnetron sputtering at ambient temperature. In this method, the optical band gap for TiO2 thin films is between 3.15–3.85 eV, and for SiO2 thin films, it is between 3.2–3.8 eV. The optical properties, including reflectance, transmittance, and absorbance, of TiO2, SiO2, and Ag thin films in the form of single and multilayer thin films in the wavelength range of 200–2500 nm, were investigated using an ultraviolet-visible-near infrared (UV–vis-NIR) dual-beam spectrophotometer. In the TiO2/Ag/SiO2 multilayer thin film, the rejection was 58.6% −73.6% in the NIR wavelength range (800–2500 nm), and a transmittance of 40%–45% was achieved in the visible light range (400–700 nm).

Theoretical simulation of pre-sintering effect and improvement of electrical transport properties of La0.7Ca0.18Sr0.12MnO3 film prepared by spin coating method

Perovskite manganites Lax(Ca1-ySry)1-xMnO3 have drawn the plentiful attention owing to their distinctive physical properties. Their unique properties make them an ideal candidate for high-sensitivity and uncooled bolometric applications. Optimized La0.7Ca0.18Sr0.12MnO3 (LCSMO) films were grown on (00l) LaAlO3 substrate at different pre-sintering temperature (Tps) via sol–gel spin coating method. According to the test results of microstructure, internal strain, Mn ion valences and surface morphology, electrical transport properties are restricted by MnO6 octahedron distortion and film crystallinity affected by the change in Tps. The microstructure growth was improved and the surface morphology tended to grow in a cross-like structure with high crystallinity by optimizing Tps. Double exchange mechanism and internal strain were enhanced with the increase in Tps. Thereby, due to the enlarging MnOMn bond angle and enhancing MnO covalency, the temperature (Tk) corresponding to temperature coefficient of resistivity (TCR) was increased gradually as Tps increased. The TCR value of LCSMO film reached a maximum value (10.82 %/K) and Tk reached room temperature (302.03 K) at Tps = 1123 K. The theoretical foundation of the pre-sintering effect has been supplemented, helping to understand the influence of pre-sintering on film growth and electrical transport properties.

Study of gold doping in optical and electrical properties of tungsten trioxide thin films deposited by spray method

Study of gold doping in optical and electrical properties of tungsten trioxide thin films deposited by spray method

Influence on Post-treatment Process on Optical and Electrical Properties of IZO Thin Films

Influence on Post-treatment Process on Optical and Electrical Properties of IZO Thin Films

Methodology for parameters extraction with undoped junctionless EZ-FETs

The junctionless EZ-FET is a simple FDSOI-like device that requires only two lithography levels and standard processing steps. With its simplified architecture and fabrication flow, and using undoped source and drain terminals, the device allows for a fast electrical evaluation of semiconductor films on insulators (SOI) and gate stacks. This paper describes an electrical model that reproduces the peculiar transfer characteristics of a junctionless EZ-FET. The model is then simplified to develop a pragmatic parameter extraction methodology. This methodology is experimentally validated and provides the electrical properties of SOI films (mobility, threshold voltage) for both electrons and holes.

Ferroelectric and electric field cycling properties of un-doped HfO2 films

As the most promising candidate material for nonvolatile memories, premature occurrence of fatigue phenomenon for ferroelectric HfO2 film has no appropriate solution method. In this paper, HfO2/Y/HfO2 films were deposited with reactive magnetron sputtering and realized ferroelectric property after wake-up process even if without doping and post-metallization annealing (PMA). Different with uniform or symmetrical distribution, oxygen vacancies concentrated in the film middle, resulting in a longer migration path and tardy fatigue. Fatigue appeared after the electric field cycling of 109 in HfO2 film inserted with 0.6 nm metal Y, which is obviously higher than films deposited by other methods. The remanent polarization of un-doped HfO2 films inserted with 0.6 and 1.5 nm metal Y interlayer is 11.8 and 14.8 μC/cm2, respectively. The results provide a method for to improve cycling property and confirm the important role of oxygen vacancies in wake-up and fatigue phenomenon for HfO2 films.

Influence of low temperature annealing time on CdS thin films

In this work, a low temperature annealing process is shown to improve the photoresponse time of CdS thin films. The films were deposited on glass substrates by chemical bath deposition. The samples were annealed in air for different times (0, 2, 4 and 6 h) at 200 °C. The morphology, optical and electrical properties of the CdS thin film was studied. The films were characterized by scanning electron microscope, X-ray diffraction, spectroscopic ellipsometry, 3D optical profilometry and UV–vis spectroscopy. The CdS thin films presented a compact structure with a grain size of approximately 80–100 nm. The average thickness of the films was 200 nm. All films exhibited a cubic CdS phase with preferred orientation along the (111) direction. The average value of the crystallite size was 30 nm. The refractive index varied from 2.40 to 2.64 as the annealing time increased. The optical bandgap for the samples showed a decreasing trend as the annealing time increased from 2.36 eV to 2.24 eV while the Urbach's energy had an inverse behavior from 0.160 eV to 0.270 eV. The annealing time was studied in the photoresponse of CdS films under ultraviolet and blue light. The fastest rise and fall times were 190 ms and 90 ms respectively for the 4 h annealing under blue light. We show that a low annealing temperature is possible to improve the photoresponse by 2 orders of magnitude.

Optical and electrical properties of Al-doped ZnO thin films deposited by sol-gel method

The multilayer (10 layers) Al doped ZnO (AZO) thin films were deposited on glass substrate by sol-gel & dipping method. X-Ray diffraction measurements showed that the AZO films were polycrystalline with a hexagonal wurtzite structure. The morphological properties of the films were analyzed by atomic force microscopy showing continuous and homogeneous film, completely covering the substrates. The thickness, optical constants, optical band gap (Eg) and transmittance (T) of AZO films were assessed by spectroscopic ellipsometry on UV-vis-NIR spectral range. The AZO film has high transmittance above 80% in the visible region and the optical band-gap energy around 3.7 eV. The electrical characteristics regarding conductivity, mobility and carrier concentrations, were measured by Hall Effect measurements (van der Pauw method). The bulk carrier concentration of the AZO film with 10 layers was found to be 1.16x1019 cm-3. The vibrational bands were obtained by Raman analysis. Defects due to oxygen vacancies in the prepared AZO films were evidenced by photoluminescence spectroscopy (PL). The optical and electrical properties of the AZO thin films proved the possibility to be used in optoelectronic applications.

Uncovering optical, magnetic, and electrical properties of epitaxial nitrogen-doped lithium ferrite films

The powerful means of nitrogen doping has been applied to perovskite, rocksalt, anatase, and fluorite oxides to tailor crystal structures, electronic/chemical states, and resultant physical/chemical properties for electronic/optical/magnetic device, catalysis, and energy conversion. However, it is rare for nitrogen-doped spinel oxides, especially for spinel ferrites. Here, we take spinel lithium ferrite (LiFe5O8) as an archetype to elucidate the nitrogen doping effect on the optical, magnetic, and electrical properties. The nitrogen dopants in lithium ferrite oxynitride (LiFe5O8-xNy) epitaxial films have been systematically manipulated by adjusting the deposition atmospheres during sputtering growth. Remarkably, nitrogen doping leads to a significant enhancement in both light absorption (approximately twice as enhanced at 2.1 eV) and electrical performance (up to 6 order enhancement) for lithium ferrites. The combined experimental and theoretical studies reveal that the nitrogen doping effect can effectively narrow the bandgap and create in-gap states that give rise to enhanced light absorption and electrical performance. Our study sheds light on a profound understanding of nitrogen doping-tailored crystal and electronic structures of spinel ferrites and provides a novel, easy, and effective route to magnetic semiconducting ferrite oxynitrides with boosted light absorption and electrical performance, which can be beneficial to spintronic and photochemistry applications.

Effect of Nitrogen Ratio on Structural, Electrical and Cell Adhesion Properties of TiZrN Thin Films Deposited at Room Temperature by Magnetron Sputtering

Effect of Nitrogen Ratio on Structural, Electrical and Cell Adhesion Properties of TiZrN Thin Films Deposited at Room Temperature by Magnetron Sputtering

Impact of atomic layer deposition temperature on electrical and optical properties of ZnO:Al films

This work highlights the impact of growth temperature on the electrical and optical properties of Al-doped ZnO (AZO) films deposited by the atomic layer deposition (ALD) technique. The ALD process and super-cycle sequence have been optimized, identifying their influence on film resistivity. By using this optimum ALD procedure, the optical and electrical properties of AZO films have been widely analyzed considering the deposition temperature. Results show promising values with film resistivity in the range of 1 mΩcm and average optical absorption below 2% for 50 nm thick AZO layers. Hall effect, X-ray diffraction and ellipsometry measurements point out that these excellent values are related to their high carrier concentration and mobility, crystalline phase and optical band gap, resulting in ALD AZO films with excellent properties to be applied in photovoltaic devices as transparent conductive oxide electrode.

The Effect of 1-Ethyl-3-Methylimidazolium Acetate on the Structural, Morphological and Electrical Properties of Poly (methyl methacrylate) (PMMA)-based Electrolyte Films

In this study, the ionic liquid (IL) of 1-ethyl-3-methylimidazolium acetate, [EMIM][Ac] was incorporated into the PMMA-based electrolyte via solution casting technique. Lithium triflate (LiTf) was also doped into the system to provide additional charge carrier. The effect of various amount [EMIM] [Ac] towards the structural, morphological, and electrical properties of PMMA-based PE films were determined using Fourier transform infrared spectroscopy (FTIR), optical microscope (OM) and electrochemical impedance spectroscopy (EIS) respectively. Solid, flexible, and free-standing films of PMMA-based electrolyte were successfully obtained after the addition of IL. As confirmed from FTIR analyses, there occurs interaction between the oxygen atoms of PMMA with the imidazolium cation of the IL. With the addition of IL, the ionic conductivity was also observed to increase which can be related to the large structure of IL that occupy the space between PMMA chain hence reduced the formation of hydrogen bonding. This has been further confirmed by the OM analyses which showed the increase in grain size for the modified PMMA system after the doping of IL. The highest conductivity of 9.86 x 10-7 S cm-1 was obtained when 42 wt.% IL (PMMAIL5) was incorporated into the PMMA-based electrolyte system. This is due to the increase in the amorphosity of the sample which improved the ion diffusion within the polymer complex. The increase in the amorphosity of the sample is confirmed by the reduced in the number of grains as observed in the optical micrograph of PMMAIL5.

Facile preparation of KNN thin film with high purity phase and excellent electrical properties

Obtaining high purity alkali niobate (K x Na1-x NbO3) thin films without secondary phase on metal coated traditional silicon (Si) substrates via sol–gel technique has remained great challenges until now. Herein, we report K0.5Na0.5NbO3 (KNN) thin films successfully deposited on Pt/Ti/SiO2/Si(100) substrates by a simply effective sol–gel process. A comprehensive and systematic investigation of processing conditions on the microstructures and electrical properties of spin-coated KNN films was presented. We have found that phase purity and microstructures of KNN films are strongly influenced by content of alkali excess and the annealing temperature. Thin films with an equal excess amount of 10% mol K and Na (KNN1) sintered at 650 °C show high crystallinity with a preferred (100)-orientation degree of 78%, and homogeneous and dense surface with columnar structure and large grain size up to 254 nm. The result of quantitative XPS analysis has proved that the composition of the film is close to the chemical stoichiometry. As a consequence, the obtained KNN1 films exhibit a large dielectric constant of 775 and low dielectric loss of ∼2% in the wide frequency range from 1kHz up to 10MHz as well as the best shape of P−E loops. Furthermore, leakage current density of the film is about 9.45 × 10−5 A cm−2 at E ≈100 kV cm−1.

Exploring the morphological surface resistance and optical absorption of thin black carbon nanotube films for electronic and optoelectronic devices

This study investigates the optical and electrical properties of thin black films of carbon nanotubes (CNTs) fabricated under various conditions to explore their potential integration as either a perfect broadband absorber or enhanced counter electrode. The study involves SEM measurements, surface resistance measurements, and UV–Vis. spectrometer analysis. The results show that the CNT thin films exhibit high electrical conductivity and strong light absorption across various wavelengths. Optically, we investigated the impact of varying the growth temperature and catalyst temperature on the absorption profile of the thin films. The fabricated and deposited CNTs showed broadband absorption spectra, reaching 92.8% of the commercial reference sample, covering both visible and near-infrared spectra. Alternatively, the morphological surface resistance for the CNT thin films recorded agonist commercial CNT samples and FTO-coated glass. An average surface resistance of 20.5 Ω/Sq.

Organic Hole‐Transport Layers: An Innovative Approach for Efficient Perovskite Light‐Emitting Diodes

AbstractOrganic–inorganic‐halide‐perovskite (OIHP) based light‐emitting diodes (LEDs) are becoming more and more well‐described as having multiple potential uses in lighting and display technology, owing to their broad color gamut and high color purity. Recent research reveals that hole‐transport layers (HTLs) perform crucial roles in realizing high‐performance and highly stable perovskite light‐emitting diodes (PeLEDs). However, the exploration of organic HTLs for obtaining efficient PeLEDs has lagged behind compared to electron‐transport layers. In the past few years, some innovative HTLs have been developed for PeLEDs, which have demonstrated excellent performances in the devices. It has been established that HTL/OIHP interface has a significant impact on the crystallization behaviors and electrical properties of OIHP film. Herein, different types of organic HTLs (polymer/small molecule) used for PeLEDs are discussed. Also, the mechanism of action of those HTLs in perovskite devices is also presented. Moreover, the recent progress of organic HTLs in blue, green, and red PeLED devices is highlighted. Furthermore, the strategies to improve the performance of existing standard HTLs are also reviewed. Additionally, the challenges present in the PeLED technology are briefly summarized. Lastly, viewpoints regarding the ongoing obstacles and forthcoming prospects are emphasized.

Fabrication of garnet solid electrolytes via sputtering for solid-state batteries

In this study, the deposition of Li7La3Zr2O12 (LLZO) thin films onto MgO substrates was successfully achieved using the radio frequency magnetron sputtering technique. The deposition process was carried out at various substrate temperatures to investigate their influence on the film properties The as-deposited films were initially amorphous; however, they could be crystallized into the cubic phase by increasing the deposition temperature above 100 °C. Upon raising the deposition temperature to 200 °C, the peaks in the X-ray diffraction pattern became sharper and more intense, indicating an increase in the volume fraction and crystallite size of LLZO.At 200 °C, the film consisted predominantly of the conductive crystalline LLZO phase, resulting in a remarkably high ionic conductivity of about 10−4S cm−1. The film deposited at 300 °C exhibited the second phase, i.e., the La2Zr2O7 phase, which resulted from excessive lithium losses. These findings highlight the importance of controlling the deposition temperature to achieve the desired crystalline phase and optimize the electrical properties of LLZO thin films.

Pengaruh Perbedaan Suhu Kalsinasi terhadap Band Gap dan Konduktivitas Listrik Lapisan Tipis CuSnO3

The main semiconductor materials used are the elements Ge (germanium) and Si (silicon). The element Ge is found in nature in small quantities and silicon is the most abundant element in the earth's crust but its conductivity is low. The semiconductor material that has recently been frequently researched is Copper Tin Oxide (CuSnO3). CuSnO3 has high electrical conductivity and is quite abundant on the earth's surface. The synthesized CuSnO3 semiconductor is applied as a thin layer because of several advantages such as large output voltage, small electrode mass, and also a fairly long service life. This research aims to determine the optical and electrical properties of CuSnO3 thin films synthesized using the sol-gel method with dip coating techniques. CuCl2·2H2O, SnCl2·2H2O, methanol, and monoethanolamine (MEA) are the precursors used. The synthesized CuSnO3 thin layer was characterized using a UV-DRS instrument to determine the band gap value and tested using the four point probe method to determine its electrical conductivity. The band gap values with calcination temperatures of 500°C, 550°C, and 600°C are 2.55 eV, 2.83 eV, and 2.95 eV, respectively, with electrical conductivity of 348.46 102 S/cm, 155.48 102 S/cm, and 107.63 102 S/cm. From these data it can be concluded that the band gap value of the CuSnO3 thin layer will increase when the calcination temperature used is higher, and the conductivity decreases as the band gap value of the CuSnO3 thin film increases.