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Recently, researchers have shown a strong interest in research on quaternary semiconductor copper zinc tin sulfide (CZTS) photovoltaic cells. These cells have a high absorption coefficient, a direct bandgap, and excellent electrical properties. However, the toxicity of cadmium (Cd) in the cadmium sulfide (CdS) buffer layer in standard CZTS solar cells, can generate severe environmental contamination that is hazardous to humans. As a result, building a Cd‐free CZTS solar cell is critical. Meanwhile, given that the peak power conversion efficiency of CZTS solar cells stands at a modest 11%, this study is dedicated to identifying an optimal approach for replacing the environmentally hazardous CdS layers to enhance overall efficiency. SCAPS‐1D is a one‐dimensional solar cell simulation program commonly used to examine proposed solar cells without building them. This study highlights the performance of CZTS with various nontoxic buffer layers, as well as the key results obtained through numerical research with SCAPS‐1D. [ABSTRACT FROM AUTHOR]

Solar cells are pivotal in harnessing renewable energy for a greener and more sustainable energy landscape. Nonetheless, eco-friendly materials for solar cells have not been as extensive as conventional counterparts, highlighting a significant area for further investigation in advancing sustainable energy technologies. This study investigated natural dyes from cost-effective and environmentally friendly blueberries and mulberries. These dyes were utilized as alternative sensitizers for dye-sensitized solar cells (DSSCs). Alongside the natural dyes, a green approach was adopted for the DSSC design, encompassing TiO2 photoanodes, eco-friendly electrolytes, and green counter-electrodes created from graphite pencils and candle soot. Consequently, the best-optimized dye sensitizer was mulberry, with an output power of 13.79 µW and 0.122 µW for outdoor and indoor environments, respectively. This study underscored the feasibility of integrating DSSCs with sensitizers derived from readily available food ingredients, potentially expanding their applications in educational kits and technology development initiatives. [ABSTRACT FROM AUTHOR]

Polymer-dispersed liquid crystal (PDLC) film is an active smart film penetrating the market due to its unique functionalities. These functional characteristics include switchable tint capabilities, which shield building residents from the sun's harmful ultraviolet (UV) rays, improve energy-saving features, and produce higher cost-efficiency. Although PDLC films are promising in several applications, there is still ambiguity on the performance of PDLC films. Particularly, the sizing effects' (such as film thickness and area) correlation with visible light transmission (VLT), ultraviolet rejection (UVR), infrared rejection (IRR), light intensity, current consumption, and apparent power consumption is not well understood. Therefore, this study investigated the sizing effects of PDLC films, including the thickness effect on VLT, UVR, IRR, light intensity, and area influence on current and apparent power consumptions. The varying applied voltage effect on the light transmittance of the PDLC film was also effectively demonstrated. A 0.1 mm PDLC film was successfully presented as a cost-efficient film with optimal parameters. Consequently, this study paves the way for a clearer understanding of PDLC films (behavior and sizing effects) in implementing economic PDLC films for large-scale adoption in commercial and residential premises. [ABSTRACT FROM AUTHOR]

Currently, halide perovskites (HPs) are gaining traction in multiple applications, such as photovoltaics and resistive switching (RS) devices. In RS devices, the high electrical conductivity, tunable bandgap, good stability, and low-cost synthesis and processing make HPs promising as active layers. Additionally, the use of polymers in improving the RS properties of lead (Pb) and Pb-free HP devices was described in several recent reports. Thus, this review explored the in-depth role of polymers in optimizing HP RS devices. In this review, the effect of polymers on the ON/OFF ratio, retention, and endurance properties was successfully investigated. The polymers were discovered to be commonly utilized as passivation layers, charge transfer enhancement, and composite materials. Hence, further HP RS improvement integrated with polymers revealed promising approaches to delivering efficient memory devices. Based on the review, detailed insights into the significance of polymers in producing high-performance RS device technology were effectively understood. [ABSTRACT FROM AUTHOR]

In this twenty-first century, energy shortages have become a global issue as energy demand is growing at an astounding rate while the energy supply from fossil fuels is depleting. Thus, the urge to develop sustainable renewable energy to replace fossil fuels is significant to prevent energy shortages. Solar energy is the most promising, accessible, renewable, clean, and sustainable substitute for fossil fuels. Third-generation (3G) emerging solar cell technologies have been popular in the research field as there are many possibilities to be explored. Among the 3G solar cell technologies, perovskite solar cells (PSCs) are the most rapidly developing technology, making them suitable for generating electricity efficiently with low production costs. However, the toxicity of Pb in organic–inorganic metal halide PSCs has inherent shortcomings, which will lead to environmental contamination and public health problems. Therefore, developing a lead-free perovskite solar cell is necessary to ensure human health and a pollution-free environment. This review paper summarized numerous types of Sn-based perovskites with important achievements in experimental-based studies to date. [ABSTRACT FROM AUTHOR]

Over the past few decades, electrochromism has been a prominent topic in energy-saving applications, which is based on the mechanism of altering the optical transmittance of EC materials under the effect of a small applied voltage. Thus, tungsten oxide (WO3) is a significant chemical compound typically applied in electrochromic devices (ECDs) as it is responsible for the optical transmittance variation. In this work, the WO3 films were produced through a sol–gel spin-coating method. The effect of various transparent conducting oxides (TCOs, which are indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO) glass substrates, and aluminum-doped zinc oxide (AZO)) was investigated in the construction of ECDs. Based on a conducting polymer polypyrene carbonate electrolyte, ITO and aluminum-doped zinc oxide (AZO)-coated glasses were also examined as counter electrodes. The electrode combination employing FTO and ITO as the TCO and counter electrode, respectively, exhibited the most significant coloration efficiency of 72.53 cm2/C. It had coloring and bleaching transmittance of 14% and 56%, respectively, with a large optical modulation of 42%. In addition to that, ECDs with the AZO counter electrode have the advantage of lower intercalation charges compared to ITO and FTO. Hence, this research offers a new avenue for understanding the role of common TCO and counter electrodes in the development of WO3-based ECDs with conducting polymer electrolytes. [ABSTRACT FROM AUTHOR]

In order to curb high electricity usage, especially in commercial buildings, smart windows, also known as "switchable" or "smart" glasses, have attracted a significant amount of attention in an effort to achieve energy savings in eco-friendly buildings and transportation systems. Smart windows save energy by regulating the input of solar heat and light and hence cutting down air-conditioning expenses, while maintaining indoor comfort. This is achieved by electrochromism, which is defined as the reversible colour change in electrochromic (EC) materials from transparent to dark blue and vice versa under a small applied voltage. Recent state-of-the-art electrochromic devices (ECD) adopt liquid-based electrolytes as the main source of energy for basic operations. While this has resulted in much success in ECDs as reported in past studies, there remain several drawbacks to this aspect, such as liquid electrolyte leakage and evaporation, not to mention safety concerns related to the harmful nature of electrolyte materials. This paper aims to review the recent advances in various solid electrolytes that are potential solutions to the mentioned problems. [ABSTRACT FROM AUTHOR]

Thin-film transistors (TFTs) are core elements of novel display media on rigid or flexible substrates, radio-frequency identification tags on plastic foils, and other large area electronic applications. Microcrystalline silicon TFTs prepared at temperatures compatible with flexible substrates (150–200 °C) have gained much attention as potential elements for such applications due to their high charge carrier mobilities. Understanding the relationship between the structural properties and the charge transport is essential in realizing TFTs with high charge carrier mobility at low temperatures. In this study, top-gate staggered microcrystalline silicon TFTs were realized by plasma-enhanced chemical vapor deposition at maximum temperature of 180 °C. We investigated the correlation between the structural properties of the microcrystalline silicon channel material and the performance of the microcrystalline silicon TFTs. Transistors with the highest charge carrier mobility, exceeding 50 cm2/V s, were realized near the transition to amorphous growth. The results reveal that electronic defects at the grain boundaries of the silicon crystallites are passivated by the amorphous phase near the transition to amorphous growth. The crystalline volume fraction of the channel material will be correlated with the transistor parameters such as charge carrier mobility, threshold voltage, and subthreshold slope. [ABSTRACT FROM AUTHOR]

Top-gate staggered microcrystalline silicon thin-film transistors (μc-Si:H TFTs) were prepared by plasma enhanced chemical vapor deposition at temperatures below 200 °C. The μc-Si:H TFTs exhibit high effective electron mobilities (device mobilities) of up to 35 cm2/V s for long channel devices. Due to the high carrier mobility μc-Si:H TFTs are promising devices for large area electronics such as organic light-emitting diode displays or radio frequency identification devices. The fabrication process of the μc-Si:H TFTs is similar to the fabrication process of amorphous silicon thin-film transistors, which facilitates an easy transfer of the technology to industry. In this paper, the influence of postfabrication low temperature thermal annealing (150 °C) on the device properties of top-gate staggered μc-Si:H TFTs is investigated. Low temperature thermal annealing reduces the device threshold voltage and subthreshold slope. Furthermore, the annealing step results in an increase of the effective mobility for long channel transistors, whereas the effective mobility for short channel transistors is reduced. The influence of the postfabrication low temperature thermal annealing on the device performances will be discussed in detail. [ABSTRACT FROM AUTHOR]

In recent year, considerable interest has been addressed towards the high energy usage in buildings for indoor comfort due to the less energy efficient windows. Electrochromic (EC) smart window is a new technology that is capable of changing from transparent to opaque and has the potential in energy saving applications. Tungsten oxide (WO 3) is a transition metal oxide with a wide range of applications which include electrochromic (EC) smart windows, displays and rear-view mirrors. In EC smart windows, WO 3 is the key element where it is responsible for the colouring and bleaching of the device. Therefore the properties of WO 3 will affect the EC performance. In this work, WO 3 films were deposited on tin doped indium oxide (ITO) coated glasses via the sol-gel spin-coating technique. The WO 3 film thicknesses were varied by means of number of deposited layers. The film thickness, morphological, structural, optical and EC properties were characterised by using step profilometer, scanning electron microscopy (SEM), X-ray diffraction (XRD) spectroscopy, ultraviolet-visible (UV-Vis) spectrophotometer and cyclic voltammetry (CV) and chronoamperometry (CA) measurements, respectively. • This manuscript elucidates the influence of film thickness on the electrochromic performance of the WO 3 films. • XRD results showed improved crystallinity with increasing WO 3 film thickness. • The area under the cyclic voltammetry (CV) curves increases as WO 3 film thickness increases. • The optical transmittance in the coloured and bleached states decreases with increasing WO 3 film thickness. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is a key material in the field of transparent large-area electronics. Some of the ZnO applications in large-area electronics include sensors, transistors and solar cells. In this work, ZnO films doped with aluminium (Al), gallium (Ga) and titanium (Ti) with different doping concentrations were deposited on glass substrates via the radio frequency (R.F.) plasma magnetron sputtering technique. The correlations of different doping concentration with the structural, optical and electrical properties were investigated by Atomic Force Microscopy, Ultraviolet-Visible Spectrometer and Hall Electronic Transport Measurement System, respectively. [ABSTRACT FROM AUTHOR]

The electrochromic (EC) window is a promising energy-saving smart window that can vary between three states: transparent, translucent, and opaque by applying low voltages. One of the potential EC materials is known as titanium dioxide (TiO 2) due to its unique chemical and physical properties. Conventional post-annealing has been commonly employed for phase transition in EC thin films, but it suffers from drawbacks such as long treatment time and high energy consumption. Hence, in this study, TiO 2 thin films were deposited on indium-doped tin oxide (ITO) and fluoride-doped tin oxide (FTO) glass substrates using a sol-gel spin coating technique, followed by a rapid post-annealing interval of 5 min at temperatures ranging from 300 to 450 °C. The optical, morphological, structural, and EC properties of TiO 2 thin films were investigated. The measurement depicted that rapid post-annealing was a cost-effective and time-saving method for realising high-quality TiO 2 EC thin films. Hence, this approach reduces the overall fabrication time and minimises energy consumption, rendering it an environmentally friendly process. The successful deployment of TiO 2 in EC applications paves the way for integrating EC and photovoltaic technologies in energy-saving window glass applications, considering TiO 2 is a crucial element in photovoltaic devices. • TiO 2 EC layer was fabricated via sol-gel spin coating technique. • Thermal annealing were shortened to 5 min to demonstrate the rapid post-annealing effect. • TiO 2 film deposited on FTO substrates exhibited superior performance compared to theTiO 2 /ITO. [ABSTRACT FROM AUTHOR]

[Display omitted] • Simplified hydrothermal route to fabricate TiO 2 photoanodes. • Eliminated additional methodological steps involving complicated equipment. • TiO 2 -based dye-sensitized solar cell (DSSC) demonstrate comparable efficiency to commercial TiO 2. Globally, the hydrothermal method is widely adopted in synthesizing TiO 2 photoanodes for various applications, including dye-sensitized solar cells (DSSCs). Nonetheless, this method typically involves several synthesis steps, and most reported works were intricate and complex to follow. In this work, a reinvented novel methodology for hydrothermal synthesis was successfully developed. The mixed-phase of anatase-rutile TiO 2 photoanodes was demonstrated by omitting several intermediate hydrothermal steps. Using the reinvented methodology, the DSSC devices presented a comparable and excellent power conversion efficiency (η = 3.30%) to commercial TiO 2 -based DSSCs (η = 3.81%). Hence, this preliminary study provided new perspectives toward simplifying wet chemical synthesis TiO 2 techniques for the design structure of DSSCs. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cell (DSSC) attracts immense interest in the last few decades due to its various attractive features such as low production cost, ease of fabrication and relatively high conversion efficiency, which make it a strong competitor to the conventional silicon-based solar cell. In DSSC, photo-anode performs two important functions, viz. governs the collection and transportation of photo-excited electrons from dye to external circuit as well as acts as a scaffold layer for dye adsorption. The photo-anode usually consists of wide band gap semiconducting metal oxides such as titanium dioxide (TiO2) and zinc oxide (ZnO) deposited on the transparent conducting oxide substrates. The morphology and composition of the semiconductor oxides have significant impact on the DSSC photovoltaic performance. Therefore, enormous research efforts have been undertaken to investigate the influences of photo-anode modifications on DSSC performance. The modifications can be classified into three categories, namely interfacial modification through the introduction of blocking and scattering layer, doping with non-metallic anions and metallic cations and replacing the conventional mesoporous semiconducting metal oxide films with one-dimensional or two-dimensional nanostructures. In the present review, the previously mentioned modifications on photo-anode are summarized based on the recent findings, with particular emphasis given to published works for the past 5 years. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cell (DSSC) has been extensively researched over the past few decades due to its facile and low-cost fabrication process compared to the silicon solar cell. Generally, the photo-anode of the DSSC consists of a titanium dioxide (TiO 2) film deposited on a transparent conducting oxide (TCO) substrate. Hydrothermal method is the most widely adopted technique for the synthesis of TiO 2 photo-anode. Nevertheless, the optimum hydrothermal synthesis parameters have yet to be elucidated. In this work, the influences of hydrothermal duration on the self-assembled TiO 2 photo-anode were investigated. It was discovered that the rutile content in the TiO 2 photo-anodes can be controlled by adjusting the hydrothermal durations. The highest DSSC efficiency of 3.88% was achieved at an optimum hydrothermal duration of 10 h, corresponding to a rutile content of 80.43%. The improvement in DSSC efficiency can be ascribed to the reduced electron-hole recombination resulting from electron transfer from rutile to anatase lattice trapping sites, thereby improving the photocurrent. However, when the hydrothermal durations exceeded 10 h, the DSSC efficiency dropped due to the agglomeration of the rutile TiO 2 resulted from excessive rutile content, which led to decreased surface area for dye adsorption and hence lower photocurrent. The results suggest the importance of controlling the hydrothermal duration on the synthesis of TiO 2 photo-anode. • Anatase-rutile mixed phase TiO 2 photo-anodes were integrated into DSSCs. • Prolonged hydrothermal duration led to increasing rutile content in photo-anodes. • Highest DSSC efficiency of 3.88% was achieved at 10h hydrothermal duration. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is a promising material in a variety of applications including sensors, transistors and solar cells. Many researchers studied N-type ZnO films and reported enhanced properties. On the other hand, P-type ZnO films were rarely attempted due to the self-compensation effect. Success in achieving P-type ZnO films is important as it will pave the way for more advanced complementary devices. In this work, P-type sodium and potassium doped ZnO films were fabricated on glass substrates with doping concentration between 0 and 25 at.%. The influences of doping concentration on surface morphology, structural, optical and electrical properties were investigated using atomic force microscopy, X-ray diffraction spectroscopy, energy-dispersive X-ray spectroscopy, ultraviolet-visible (UV-Vis) spectrophotometer, photoluminescence spectroscopy and Hall-effect electrical transport measurement system. The distinctive behavior of P-type ZnO films with different doping concentrations will be discussed. [ABSTRACT FROM AUTHOR]

In this work, the influences of catalyst materials of counter electrodes – carbon (C) and platinum (Pt) electrodes, transparent conducting oxide (TCO) substrates – fluorine-doped tin oxide (FTO) and indium-doped tin oxide (ITO) glasses and dyes (N3 and N719 dyes) on the photovoltaic performance of dye-sensitised solar cells (DSCCs) were investigated. DSSC was fabricated with standard configuration: a mesoporous TiO2layer (15–20 nm particle size, anatase phase) deposited on ITO/FTO glass as photoanode, N3/N719 (Solaronix) as dyes, chenodeoxycholic acid as co-adsorbent in dye solution, Pt-coated/C-coated glass as counter electrode and Iodolyte AN-50 (Solaronix) as electrolyte. The optimised DSSC demonstrated photovoltaic performance of short-circuit photocurrent density (Jsc) of 8.36 mA/cm2, open-circuit photovoltage (Voc) of 0.69 V and a fill factor (FF) of 0.70, corresponding to power conversion efficiency (PCE) of 4.05% under simulated air mass 1.5 solar light condition. [ABSTRACT FROM PUBLISHER]

Purpose This paper aims to develop a low-cost hot-point which can facilitate the conductivity type of N-type and P-type zinc oxide (ZnO) films. In this study, a diode was made out of the N-type and P-type ZnO films, and current-voltage (I-V) characteristic measurements were conducted.Design/methodology/approach A low-cost hot-point probe consists of a soldering iron station, digital multimeter and a pair of probes. The setup is adopted to identify N-type and P-type ZnO films. In particular, P-type films have been deployed for the first time.Findings Hot-point probe setup has been successfully developed. Measurements of N-type films give a positive voltage reading, whereas P-type films give a negative voltage reading. The measured voltage dominates at 1 per cent for N-type Ga and at 15 per cent for P-type Na. I-V characteristics of the fabricated diode showed a similar trend to the conventional diode.Research limitations/implications N-type has been often attempted. However, P-type has rarely been attempted because of the self-compensation effect in ZnO. There is a need to verify the conductivity type of ZnO films, especially P-type, as P-type films are not stable. The hot-point probe setup serves as a quick means to verify P-type ZnO films.Originality/value To the best of the authors’ understanding, this verification tool was developed and deployed to verify the N-type and P-type ZnO films. The P-type films are coated on top of the N-type films for diode I-V measurements. [ABSTRACT FROM AUTHOR]

Abstract: The design and operation of ambipolar transistors and inverters were studied. In order to gain insights in the operation of ambipolar inverters an analytical model was developed which describes the electrical behavior of ambipolar transistors and inverters. The model was compared to experimentally realized inorganic and organic ambipolar thin-film transistors and inverters. Furthermore, the influence of the transistor parameters on the voltage transfer characteristics and the static noise margin are discussed. The model provides a general description which is applicable to a variety of ambipolar transistor technologies based on different material systems. [Copyright &y& Elsevier]

Abstract: Zinc oxide (ZnO) films have the potential in the emerging thin-film technologies which can be employed in thin-film solar cells, transistors, sensors and other optoelectronic devices. In this work, low cost sol–gel spin-coating technique was used to synthesize the ZnO films. The influences of annealing temperature on the structural and optical properties of ZnO and aluminum doped ZnO (AZO) films were investigated. The structural properties of the ZnO films such as surface morphology and crystallinity were determined using atomic force microscopy (AFM) and X-ray diffractometry (XRD), respectively. The optical properties of the ZnO films were characterized by the ultraviolet–visible (UV–vis) spectroscopy and Tauc method was adopted to estimate the optical gap. The experimental results reveal that the thermal annealing treatment affects the properties of the ZnO films. The effects of the low range annealing temperature on the sol–gel ZnO films addressed in this investigation will be discussed in this paper. [Copyright &y& Elsevier]

Purpose – Power management of a wireless sensor node is important and needs to be designed efficiently without wasting excessive energy. The purpose of this paper is to report on the improvement of the power management of a wireless sensor node. Design/methodology/approach – The design involves the implementation of solar recharging technology with single-ended primary inductance converter (SEPIC) on a wireless sensor node in order to achieve the improvement in power management. Findings – The combination of the solar recharging technology with SEPIC converter shows promising results for efficiently supplying the power to the wireless sensor node. Research limitations/implications – The design idea can be extended for many other electronic sensor applications, which can help to ensure an efficient power management of the sensor nodes. Originality/value – The proposed design model demonstrates a new idea towards reduction of energy usage for wireless sensor nodes. [ABSTRACT FROM AUTHOR]

The global move toward reducing the usage of lead in electronics manufacturing industry is driving the industry to switch from tin–lead alloys to pure tin (Sn) for its component plating process. This transition has resulted in a reliability concern due to the formation of conductive Sn whiskers, which can grow from the component after the plating process within a few hours to months, with their length ranging from 10 micrometers up to several millimeters. The conductive Sn whiskers may cause current leakage or short circuits, leading to catastrophic failure in the field. This paper presents the results of an experimental study on Sn whisker formation based on the effects of annealing for 1 h at 150^\circC and environmental test conditions from the joint electron devices engineering council standards. This paper consisted of one temperature cycling test and two isothermal storage tests. The characterization results obtained confirm that temperature cycling and isothermal storage favor the formation of whiskers on Sn-plated copper lead frames. The average maximum length of the whiskers increased with the number of temperature cycles and duration of isothermal storage. It is also shown that annealing for 1 h at 150^\circC of the samples is effective in reducing the average maximum length of whiskers. Growth mechanisms of the Sn whiskers due to the effects of annealing and without annealing are also discussed. [ABSTRACT FROM PUBLISHER]

Zinc oxide (ZnO) thin films and micro- and nanostructures are very promising candidates for novel applications in emerging thin-film transistors, solar cells, sensors and optoelectronic devices. In this paper, a low-cost sol-gel spin coating technique was used to fabricate ZnO films on glass substrates. The sol-gel fabrication process of the ZnO films is described. The influence of precursor concentration on the material properties of the ZnO films was investigated. Atomic force microscopy and X-ray diffractometry were employed to examine the structural properties of the ZnO films. The optical properties of the ZnO films were characterized with ultraviolet-visible spectroscopy. The experimental results reveal that the precursor concentration in the sol-gel spin coating process exerts a strong influence on the properties of the ZnO films. The effects of the precursor concentration are discussed. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of this paper is to share valuable information about metallization in microelectronic industries by implementing tungsten silicide (WSi) thin film materials. Design/methodology/approach - Direct current plasma magnetron sputtering technique was employed for the WSi film growth. Different sputtering parameters were investigated, and the WSi films were characterized using four-point probe electrical measurement method. Findings - The experimental results reveal that the sputtering parameters such as deposition pressure and substrate temperature exert significant influence on the electrical properties of the WSi films. Research limitations/implications - By tuning the sputtering parameters, the electrical properties of the WSi films can be optimized and the film resistivity can be reduced significantly. Practical implications - The investigation results presented in this paper are useful information for microelectronic industries in the area of microelectronic devices metallization. Originality/value - The fabrication method described in this paper allows fabricating low-resistivity WSi films by employing a lower deposition pressure and a lower substrate temperature. [ABSTRACT FROM AUTHOR]

Abstract: Zinc oxide (ZnO) is a very promising electronic material for emerging transparent large-area electronic applications including thin-film sensors, transistors and solar cells. We fabricated ZnO thin films by employing direct current (DC) magnetron sputtering deposition technique. ZnO films with different thicknesses ranging from 150nm to 750nm were deposited on glass substrates. The deposition pressure and the substrate temperature were varied from 12mTorr to 25mTorr, and from room temperature to 450°C, respectively. The influence of the film thickness, deposition pressure and the substrate temperature on structural and optical properties of the ZnO films was investigated using atomic force microscopy (AFM) and ultraviolet–visible (UV–Vis) spectrometer. The experimental results reveal that the film thickness, deposition pressure and the substrate temperature play significant role in the structural formation and the optical properties of the deposited ZnO thin films. [ABSTRACT FROM AUTHOR]

Abstract: Hydrogenated microcrystalline silicon (μc-Si:H) has lately attracted considerable attention as a promising candidate for thin-film transistors (TFTs) in large area electronic applications due to its superior charge carrier mobility. Here, we present ambipolar TFTs and inverters based on microcrystalline silicon prepared by plasma-enhanced chemical vapor deposition at low deposition temperature of 160°C. The electrical parameters of the ambipolar microcrystalline silicon TFTs and inverters will be described. The influence of contact effects on the operation of ambipolar microcrystalline silicon TFTs was investigated. Furthermore, the influence of the ambipolar transistor characteristics on the performance of the ambipolar inverter will be discussed. [Copyright &y& Elsevier]

Abstract: Physical vapor processes using glow plasma discharge are widely employed in microelectronic industry. In particular magnetron sputtering is a major technique employed for the coating of thin films. This paper addresses the influence of direct current (DC) plasma magnetron sputtering parameters on the material characteristics of polycrystalline copper (Cu) thin films coated on silicon substrates. The influence of the sputtering parameters including DC plasma power and argon working gas pressure on the electrical and structural properties of the thin Cu films was investigated by means of surface profilometer, four-point probe and atomic force microscopy. [Copyright &y& Elsevier]

Abstract: Thin-film inverters based on high mobility microcrystalline silicon thin-film transistors (TFTs) with different channel lengths were realized. The NMOS enhancement load saturation mode (NELS) inverters were prepared by plasma-enhanced chemical vapor deposition at temperatures below 200°C. The realization of microcrystalline silicon thin-film inverters facilitates the direct integration of column and row drivers and circuitry on display backpanels. The influence of the transistor properties and underlying contact effects on the performance of the inverters will be discussed. [Copyright &y& Elsevier]

Abstract: The influence of the crystalline volume fraction of hydrogenated microcrystalline silicon on the device performance of thin-film transistors fabricated at temperatures below 200°C was investigated. Transistors employing microcrystalline silicon channel material prepared close to the transition to amorphous growth regime exhibit the highest charge carrier mobilities exceeding 50cm2/Vs. The device parameters like the charge carrier mobility, the threshold voltage and the subthreshold slope will be discussed with respect to the crystalline volume fraction of the intrinsic microcrystalline silicon material. [Copyright &y& Elsevier]

Abstract: This paper addresses the influences of sputtering power and deposition pressure on the surface morphology and structural behavior of dc magnetron sputter-deposited copper (Cu) thin films on p-type silicon grown at room temperature. Results from our experiments show that the deposition rate of the Cu film increases proportionally with the sputtering power and decreases with deposition pressure. From the atomic force microscopy (AFM) and X-ray diffraction (XRD) analysis, high sputtering power enhances the microstructure of the Cu film through the surface diffusion mechanism of the adatom. The poor microstructure as a result of low sputtering power deposition was manifested with the smaller value of Cu film root mean square (RMS) roughness obtained. The deposition pressure has the contrary influence on structural properties of Cu film in which high deposition pressure favors the formation of voided boundaries film structure with degraded film crystallinity due to the shadowing effect, which varies with different deposition pressures. [Copyright &y& Elsevier]

Abstract: This paper addresses the effects of substrate temperature on electrical and structural properties of dc magnetron sputter-deposited copper (Cu) thin films on p-type silicon. Copper films of 80 and 500nm were deposited from Cu target in argon ambient gas pressure of 3.6mTorr at different substrate temperatures ranging from room temperature to 250°C. The electrical and structural properties of the Cu films were investigated by four-point probe and atomic force microscopy. Results from our experiment show that the increase in substrate temperature generally promotes the grain growth of the Cu films of both thicknesses. The RMS roughness as well as the lateral feature size increase with the substrate temperature, which is associated with the increase in the grain size. On the other hand, the resistivity for 80nm Cu film decreases to less than 5μΩ-cm at the substrate temperature of 100°C, and further increase in the substrate temperature has not significantly decreased the film resistivity. For the 500nm Cu films, the increase in the grain size with the substrate temperature does not conform to the film resistivity for these Cu films, which show no significant change over the substrate temperature range. Possible mechanisms of substrate-temperature-dependent microstructure formation of these Cu films are discussed in this paper, which explain the interrelationship of grain growth and film resistivity with elevated substrate temperature. [Copyright &y& Elsevier]

Abstract: This paper addresses the influences of film thickness on structural and electrical properties of dc magnetron sputter-deposited copper (Cu) films on p-type silicon. Cu films with thicknesses of 130–1050nm were deposited from Cu target at sputtering power of 125W in argon ambient gas pressure of 3.6mTorr at room temperature. The electrical and structural properties of the Cu films were investigated by four-point probe, atomic force microscopy (AFM) as well as X-ray diffraction (XRD). Results from our experiment show that the grain grows with increasing film thickness, along with enhanced film crystallinity. The root mean square (RMS) roughness as well as the lateral feature size increase with the Cu film thickness, which is associated with the increase in the grain size. On the other hand, the Cu film resistivity decreases to less than 5μΩ-cm for 500nm thick film, and further increase in the film thickness has no significant effects on the film resistivity. Possible mechanisms of film thickness dependent microstructure formation of these Cu films are discussed in the paper, which explain the interrelationship of grain growth and film resistivity with increasing Cu film thickness. [Copyright &y& Elsevier]

• Electrical model of the DSSC is established based on four parameter single-diode model. • Simplified explicit method is implemented to derive the four parameters. • Simulated I-V curves show good fitting to the corresponding experimental I-V curves. Dye sensitized solar cells (DSSCs) have been in the research limelight for some years and plenty of research were devoted to the investigation of material properties for device enhancement. The electrical modeling facilitates the simulation of the device characteristics of the DSSCs. In order to develop highly efficient DSSCs, it is crucial to elucidate the electric mechanism within the cell through the electrical modeling. In this work, we propose a simplified explicit method to estimate the four parameters (photo-generated current (I ph), saturation current (I s), ideality factor (n) and series resistance (R s)) used in the equivalent circuit by using the single diode model. By using the proposed explicit method, two series of simulated I-V curves (blocking layer and chenodeoxycholic acid additive) were generated from LTspice software by using the experiment data of current–voltage (I-V) measurements reported in our previous research. The simulated I-V curves derived from the software show good fitting to the corresponding experimental I-V curves, which demonstrate that the simplified explicit method reported here can be used to serve as an effective approach to evaluate the electrical properties of the DSSCs. [ABSTRACT FROM AUTHOR]

Electrochromic (EC) window is a novel intelligent window technology which functions by switching between transparent and opaque states thereby allowing the energy saving, healthy and comfort living environment within residential and commercial building premises. In general, each layer is important in ensuring the smooth operation of an EC window. In particular, the electrolyte layer is one of the more important layers due to the fact that its material composition will directly impact the operation of the EC window. In this work, WO 3 films were fabricated using sol-gel spin-coated technique on indium tin oxide (ITO) coated glasses. Lithium iodide in polyethylene glycol (PEG:LiI) and lithium perchlorate in propylene carbonate (PC:LiClO 4) were used as polymer electrolytes. Subsequently, the EC performance of WO 3 films using the mentioned polymer electrolytes were examined by cyclic voltammetry (CV) and chronoamperometry (CA) techniques. The optical properties of the WO 3 films were measured by using the ultraviolet-visible (UV–vis) spectrophotometer. The electrolytes based on PEG:LiI and PC:LiClO 4 have been the mainstream electrolytes with variant EC performance, and yet, the direct comparison of these polymers electrolytes were not explored. Therefore, the current work here is important to outline the characteristics of these electrolytes in determining the EC performance on WO 3 films. [ABSTRACT FROM AUTHOR]

Abstract: Hydrogenated microcrystalline silicon (µc-Si:H) has recently received significant attention as a promising material for thin-film transistors (TFTs) in large area electronics due to its high electron and hole charge carrier mobilities. We report on ambipolar TFTs based on microcrystalline silicon prepared by plasma-enhanced chemical vapor deposition at temperature of 160 °C with high electron and hole charge carrier mobilities of 40 cm2/Vs and 10 cm2/Vs, respectively. The ambipolar microcrystalline silicon TFTs provide a simple route in realizing large area integrated circuits at low cost. The electrical characteristics of the ambipolar microcrystalline silicon TFTs will be described and the first results on ambipolar inverters will be presented. The influence of the ambipolar TFT characteristics on the performance of the inverter will be also discussed. [Copyright &y& Elsevier]

Abstract: This paper discusses the influence of direct current (DC) power in the magnetron sputtering process on the crystallite size of the copper (Cu) thin films deposited on p-type silicon substrate at room temperature. X-ray diffraction (XRD) and Karl Suss four-point probe were employed to study the film crystallinity and conductivity, respectively. From the analysis on the XRD patterns, high DC power enhances the Cu film crystallinity with larger crystallite size, which is deduced using Sherrer''s formula. The behavior of the electrical property of the Cu films complies with the trend of the film crystallinity with DC power, in which the film conductivity increases with increasing DC power. We attribute these phenomena to the enhanced surface diffusion mechanism of the adatom during the sputtering deposition process, which improves the microstructure of the Cu film. [Copyright &y& Elsevier]

Microcrystalline silicon thin-film transistors were prepared by plasma-enhanced chemical vapor deposition at substrate temperatures below 200 °C. The transistors exhibit electron mobilities of 38 cm2/V s, threshold voltages in the range of 2 V, and subthreshold slopes of 0.3 V/decade. Despite the realization of transistors with high carrier mobility, contact effects limit the performance of the transistors. The influence of the drain and source contacts on device parameters including the mobility, the threshold voltage, and the subthreshold slope will be discussed in detail. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to elucidate the aging effect in dye-sensitized solar cells (DSSCs) sealed with thermoplastic film and to compare it with unsealed DSSCs. Design/methodology/approach: The paper presents the steps of the fabrication of standard DSSC, as well as the DSSC-sealing processes, by using thermoplastic film. Current-voltage characterization was performed to observe the changes in efficiency, fill factor, short circuit current density and open circuit voltage for both unsealed and sealed DSSCs for aging time up to 336 h. Findings: The unsealed DSSC showed significant drop in efficiency from 4.26 to 2.42 per cent within the first 5.5 h of aging time because of the leakage and volatilization of the solvent in the electrolyte. On the other hand, the sealed DSSC exhibited a gradual improvement of efficiency from 4.16 to 4.73 per cent after the first 216 h of aging time. The initial efficiency increment can be ascribed to the improved adsorption of electrolyte into the titanium dioxide film because of the gradual desorption of excess dye from TiO2 with increasing aging time. Originality/value: This paper demonstrates the importance of the proper sealing process for the long-term operation of DSSC. [ABSTRACT FROM AUTHOR]

ZnO is a promising material suitable for variety of novel electronic applications including sensors, transistors, and solar cells. Intrinsic ZnO film has inferiority in terms of electronic properties, which has prompted researches and investigations on doped ZnO films in order to improve its electronic properties. In this work, aluminium (Al) doped ZnO (AZO) and gallium (Ga) doped ZnO (GZO) films were coated on glass substrates by a sol–gel spin coating technique. AZO and GZO films were examined using XRD, AFM, FESEM, UV–vis spectroscopy, and Hall Effect measurement system to investigate the structural, morphology, optical transmittance, and electronic properties of the films. Highly c -axis oriented and transparent AZO and GZO films with distinct peak at 34.5° corresponding to (002) orientation were obtained. The decrease of (002) peak was observed with higher doping level. The optical transmittances in the visible region are in the range of 80–95%. Samples with 1 at% Al and 2 at% Ga showed the lowest electrical resistivity. The correlation of the doping level of Al and Ga on doped ZnO films will be revealed in this work. [ABSTRACT FROM AUTHOR]

Abstract: Zinc oxide (ZnO) is a wide band gap transparent conductive oxide (TCO) material with a lot of potential applications including transparent thin-film sensors, transistors (TFTs), solar cells, and window insulation systems. In this work, ZnO films were deposited on glass substrates by the radio frequency (RF) plasma magnetron sputtering deposition technique. The effects of the RF power on the properties of the ZnO films were elucidated. The influences of the RF power on the surface morphology, structural, and optical properties of the ZnO films were investigated by Mahr surface profilometer, Atomic Force Microscopy (AFM), X-ray diffractometer (XRD), and ultraviolet–visible (UV–VIS) spectrophotometer. To allow for accurate comparison of the power effects, ZnO films with similar thickness deposited at different RF powers were examined. The RF power effects on the properties of the ZnO films are revealed and discussed in this paper. [Copyright &y& Elsevier]

Abstract: The study of the properties of zinc oxide (ZnO) films has gained popularity recently due to its potential in a wide range of applications, such as thin-film solar cells, transistors, sensors and other optoelectronic devices. In this work, low cost sol–gel spin coating technique was employed to fabricate the ZnO films. The influences of post-annealing condition on the properties of the ZnO films were investigated. The ZnO films were annealed under ambient, nitrogen and vacuum environments at 450°C and the environment effects on the ZnO films were compared. Furthermore, the effect of cooling period allowed for the ZnO films after the post-annealing process was examined. The ZnO films were characterized using surface profilometer, atomic force microscopy, X-ray diffractometer, and ultraviolet–visible transmission spectroscopy in order to study the thickness, surface morphology, crystallinity, and optical properties of the ZnO films. The optical band gap of the ZnO films was estimated based on the thickness and the optical transmittance data. These investigations serve to clarify the effects of different post-annealing conditions in order to optimize the properties of the ZnO films. [Copyright &y& Elsevier]

Due to the growing demand of energy and wastage of energy, there exists an interest of storing energy so that it could be utilized efficiently. Capacitors are materials designed for such an application. Ferroelectric materials are known for their application as capacitors. Of such materials, perovskites are the preferable classes of materials that have been used as capacitors. Barium strontium titanate nanomaterial is a member of perovskites which encompasses a smaller dielectric loss, elevated dielectric constant, and good thermal stability. Research studies also clarified that incorporating dopants into a barium strontium titanate nanomaterial of high dielectric materials including metal/metal oxides enhances their efficiency and effectiveness. Moreover, multielement doping or codoping has shown better dielectric properties as compared to the unidoping of BST. In this review, barium strontium titanate capacitors codoped with more than one metal/metal oxides have been studied most of which have shown that the codoped barium strontium titanate materials possess improved and sufficient dielectric properties to be utilized as capacitors. We believe that this work will have of its own contribution on understanding the doped barium strontium titanate nanomaterial by clarifying the most probable and detail reasons behind the enhancement of dielectric properties of codoped barium strontium titanate nanomaterials. [ABSTRACT FROM AUTHOR]

Nanomaterials are a potential alternative to conventional random resistive access memory (ReRAM) in non-volatile memory (NVM) due to their unique electrical and physical properties. Nevertheless, obtaining a specific NVM characteristic [particularly Write-Once-Read-Many (WORM)] using carbon-based electrodes necessitates further assessment. This study proposed a reinvented methodology for TiO 2 -based devices to produce WORM memory behavior using the doctor blade method. A carbon/graphite counter electrode (Gr/Cb) was fabricated and characterized for TiO 2 -based resistive switching devices. Consequently, the Gr/Cb electrode device quickly transitioned from a high to low resistance state, suggesting WORM memory behavior. Approximately 66.7 % improvement (∼1.8 V–∼0.6 V) was observed in the required applied voltage when the active area was reduced, indicating lower power consumption. Overall, this study provided evidence of the approach's feasibility in practical applications, demonstrating lower costs and simplicity. The structure also highlighted the importance of understanding the WORM behavior for effectively utilizing carbon-based electrodes in non-volatile memories. [Display omitted] • Novel carbon-based electrodes were integrated into TiO 2 -based ReRAM devices. • The lowest ON voltage were ∼0.6 V and ∼1.8 V for ITO/TiO 2 /Gr/Cb (pixel) and ITO/TiO 2 /Gr/Cb (strip) memory devices. • WORM behavior was achieved using a TiO 2 -based ReRAM device. • VCM theory could be used to explain the ohmic behaviour and Schottky emission mechanism. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is an emerging optoelectronic material in large area electronic applications that are due to its various functional behaviors. We present the fabrication and characterizations of ZnO nanorods. The ZnO nanorods were synthesized using sol-gel hydrothermal technique on oxidized silicon (Si) substrates. In the fabrication of ZnO nanorods, the oxidized Si substrates were immersed in ZnO aqueous solution for different durations ranging from 3 hours to 5 hours. The surface morphologies of the ZnO nanorods were examined using scanning electron microscope (SEM). In order to investigate the structural properties, the ZnO nanorods were measured using X-ray diffractometer (XRD). The optical properties were measured using ultraviolet-visible (UV-Vis) spectroscopy. The effect of the immerse duration on the material properties of the realized ZnO nanorods will be revealed and discussed in this paper. [ABSTRACT FROM AUTHOR]

• Heteroleptic metal complexes of semicarbazone ligands derived from the natural product as a recent strategy to develop bioactive compounds. • Synthetic modification of natural products into semicarbazone form increases the biological activities. • Heteroleptic Cu(II) and Zn (II) complexes of ortho -phthalaldehyde and dehydrozingerone semicarbazones have shown significant antibacterial and antioxidant activities. • Molecular docking and in vitro studies together confirmed the newly synthesized compounds as potential drug candidates. In this study, we describe the synthesis of novel heteroleptic Cu(II) and Zn(II) complexes using two semicarbazone-based derivative ligands: ortho -phthalaldehyde disemicarbazone (L1) and dehydrozingerone semicarbazone (L2). The metal salts and the two ligands were used in a 1:1:1 ratio. The complexes were characterized by magnetic moment measurements, elemental analysis, SEM-EDX, liquid chromatography-mass spectrophotometer (LC-MS), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), UV-visible spectrophotometer, NMR, and FT-IR spectroscopy methods. Using the disk diffusion and DPPH procedures, the complexes' potential for scavenging free radicals and having antibacterial effects was examined. The results indicate that the ligand L 1 has good mean inhibition zones on S. aureus (12.42 ± 0.23 mm) and S. pyogenes (11.64 ± 0.12 mm) bacteria. The [Cu(L 1)(L 2)] complex displayed higher antibacterial activities (13.67 ± 0.52 mm) against S. pyogenes bacteria, whereas [Zn(L 1)(L 2)] shows higher activity against P. Aeruginosa (14.22 ± 0.33 mm). Both complexes showed good antioxidant activity (63.7 % and 59.68 %). Furthermore, the docking results of the compounds against S. aureus Gyrase confirm the ligands (L 1 and L 2) and the complexes exhibit binding potentials of -7.39 to -11.01 kcal/mol. Higher value was obtained for the [Zn(L 1)(L 2)] complex (-11.01 kcal/mol). In order to enhance the biological activities of metal complexes, this study sheds light on the significance of multi-semicarbazone ligands and their corresponding complexes. [ABSTRACT FROM AUTHOR]

The idea of Internet of Things (IoT) has brought about the innovation of smart materials and devices which affect our everyday life. One of the technologies associated to the IoT is the electrochromic (EC) smart windows and the key material is tungsten oxide (WO 3). WO 3 is considered as the best candidate due to its superior EC properties for example high optical modulation and high colouration efficiency. In this work, the structural properties of WO 3 films were manipulated by varying the post annealing temperature between 27 °C and 450 °C. The WO 3 films annealed at different temperature were characterised for their structural, morphological, optical and EC properties using X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), optical transmittance study, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The effect of post annealing temperature will be analysed and investigated which is important for smart window performance optimisation. • Improved crystallinity in WO 3 films at high annealing temperature. • CV results showed highest diffusion coefficient for WO 3 films annealed at 250 °C. • Colour patches were calculated based on the measured optical transmittance. • Colouring and bleaching transmittances decreases in denser WO 3 film structure. [ABSTRACT FROM AUTHOR]