Applications In Optoelectronic Devices Research Articles

Energy transfer from Ce3+ to Eu3+ in the spinel structure of ZnAl2O4 phosphor for optoelectronic applications

Zinc aluminate (ZnAl2O4), with a spinel structure is known for its versatile applications as catalyst, ceramic material, and optoelectronic device. ZnAl2O4 is an excellent host for trivalent rare-earth ions such as Dy3+ , Tb3+, Eu3+ and Sm3+ has been extensively investigated for application in display devices. The focus of this work is on Ce3+ and Eu3+ co-dopants aiming to address issues such as multistage combustion synthesis routes, the formation of secondary phases, that often impact luminescence intensity. Through a systematic approach, we synthesized the ZnAl2O4 host with consistent cerium concentration and varying europium ions using one-step combustion synthesis route. The findings reveal that the synthesized material exhibits efficient energy transfer, mitigates concentration quenching and demonstrates favorable color chromaticity. The crystal structure analysis confirms phase purity and addresses concerns related to secondary phase formation. The simplified and cost-effective approach of one-step combustion synthesis method for synthesizing Ce3+ and Eu3+ co-doped ZnAl2O4 suggests that this phosphor has potential applications in ultraviolet photo-electronic technology and other opto-electronic devices.

Embellished photosensitive Schottky barrier diode functionality of Ni(II)/Pb(II)-Salen complex with SCN− spacers: Insights from experimental and theoretical rationalization

This research article explores the synthesizing, structural characterizing, and photosensitive Schottky diode behaviour (PSBD) of one new hetero-nuclear Ni(II)/Pb(II)-Salen complex, [Ni2(L)Pb(μ-1,3-SCN)2(H2O)]2. The complex utilizes various analytical methods for characterization purposes, including single-crystal X-ray diffraction (SCXRD). Crystals have formed in the monoclinic space group P21/n within the compound. The complex asymmetric unit contains a deprotonated ligand (L2−), two Ni(II), one Pb(II), two SCN− ions, and Ni(II) metal coordination by H2O molecule. The crystallographic structure has octahedral and see-saw geometries around the Ni(II) and Pb(II) metal ions. The crystal structure reveals remarkable supramolecular interactions, with significant S⋯H contacts (13 %) evident from the Hirshfeld surface (HS) and 2-D fingerprint plots. The calculated optical band gap (3.14 eV) and UV–Visible measurement support the semiconductor behaviour. In addition, the compound shows electrical conductivity and photosensitivity (dark & light), suggesting potential applications in optoelectronic devices. The complex transports charge through space via a hopping process. The extensive experimental investigations indicate that exposure to visible light increases electrical conductivity compared to dark conditions, popularly known as PSBD behaviour. The complex conductivity function substantiates the DFT-based DOS, PDOS, and OPDOS plot analysis. Therefore, the heteronuclear complex has been successfully used in thin-film active devices despite technological challenges.

High-Temperature Phase Transition with Switchable Dielectric Behavior and Significant Photoluminescence Changes in a Zero-Dimensional Hybrid SbBr6 Perovskite.

In the past decade, metal halide materials have been favored by many researchers because of their excellent physical and chemical properties under thermal, electrical, and light stimuli, such as ferroelectricity, dielectric, nonlinearity, fluorescence, and semiconductors, greatly promoting their application in optoelectronic devices. In this study, we successfully constructed an unleaded organic-inorganic hybrid perovskite crystal: [Cl-C6H4-(CH2)2NH3]3SbBr6 (1), which underwent a high-temperature reversible phase transition near Tp = 368 K. The phase transition behavior of 1 was characterized by differential scanning calorimetry, accompanied by a thermal hysteresis of 6 K. In addition, variable-temperature Raman spectroscopy analysis and PXRD further verified the sensitivity of 1 to temperature and the phase transition from low symmetry to high symmetry. Temperature-dependent dielectric testing shows that 1 can be a sensitive switching dielectric constant switching material. Remarkably, 1 exhibits strong photoluminescence emission with a wavelength of 478 nm and a narrow band gap of 2.7 eV in semiconductors. As the temperature increases and decreases, fluorescence undergoes significant changes, especially near Tc, which further confirms the reversible phase transition of 1. All of these findings provide new avenues for designing and assembling new phase change materials with high Tp and photoluminescence properties.

Modulating the Electrical Properties of Lithium-Doped Zinc Oxide: Interplay of Lithium Content, Oxygen Pressure, and Temperature

This research elucidates the intricate interplay of lithium content, oxygen pressure, and temperature and their influence on the electrical properties of Lithium-doped zinc oxide (LZO). The electrical behavior of zinc oxide (ZnO), a prominent semiconductor material, can be modulated when doped with lithium (Li). Through systematic experimentation, we demonstrate that varying lithium content in the ZnO matrix leads to notable shifts in carrier concentration and mobility, which in turn impacts the material's conductivity and overall electrical performance. Furthermore, oxygen pressure during synthesis plays a pivotal role in defect formation, especially oxygen vacancies, which interact dynamically with lithium dopants to further modulate electrical behavior. Introducing the variable of temperature, our study reveals a synergistic effect, where temperature not only affects intrinsic carrier concentration but also the interactions between lithium dopants and inherent defects in ZnO. Under optimized conditions of oxygen pressure and temperature, the influence of Li content on crystallinity was pronounced, consequently impacting mobility. In contrast, under unoptimized conditions, as Li concentration increased, particularly beyond optimal levels (0.75 mol%), introduced Li atoms assumed the role of compensating centers by capturing or neutralizing carriers, reducing mobility. The findings presented herein provide a comprehensive understanding of how these factors collectively determine the electrical properties of LZO, paving the way for tailored applications in optoelectronic devices, sensors, and more.

Controlled Sixfold Symmetric Exfoliation of Oriented MoS2 Monolayers by Coulomb Force

AbstractAtoms, molecules, and nanoparticles can be spatially manipulated by an atomic force microscopy (AFM) tip, through van der Waals (vdW) and/or Coulomb forces. These point‐to‐point manipulations are highly accurate at nanoscale, facilitating the construction and modification of nanostructures. Nevertheless, it is difficult to manipulate 2D layers in vdW crystals by an AFM tip, because the tip‐induced attractive force is usually insufficient to outcompete the interlaminar vdW forces. Herein, manipulation of the surface layers on a MoS2 single crystal by a conductive AFM tip is successfully reported. By applying a bias between the tip and MoS2, the Coulomb attractive force allows the topmost MoS2 layers to be picked up. These exfoliated layers are deformed into micron‐sized bubbles with sixfold symmetry, which are composed of high‐quality monolayers and visually reflecting the hexagonal lattice orientation. The underlying mechanisms of the sixfold symmetric exfoliation and the formation of monolayers are discussed by in situ monitoring of the tunneling volt‐ampere characteristics and simulation of the force distribution. The findings open a new route to obtain high‐quality transition metal dichalcogenide (TMD) monolayers and their derived nanostructures on the surface of TMD single crystals for optoelectronic and photonic device applications.

Eco-Friendly Electrophoretic Deposition of Fluorescent Nanocomposite Films in an Aqueous Dispersion of Hydrophilized Core/Shell CuInS2/ZnS Quantum Dots for Optoelectronic Applications.

Low-toxic and efficient fluorescent core-shell CuInS2/ZnS (CIS/ZnS) quantum dots (QDs) are good candidates for optoelectronic device applications. They are synthesized in a hydrophobic environment, while large amounts of organic solvents used in the preparation of fluorescent films have significant problems on environmental load and human health. CIS/ZnS QDs hydrophilized by adsorbing 3-mercaptopropionic acid on their surfaces can be used in the aqueous film fabrication process. In this work, the aqueous electrophoretic deposition (EPD) of the hydrophilized QDs with silicone-modified acrylic resin nanoparticles was performed to fabricate fluorescent nanocomposite films. The hydrophilized QDs and resin nanoparticles were simultaneously dispersed in basic aqueous solutions due to electrostatic repulsion resulting from their negatively charged surfaces. Transparent films were obtained on a transparent conductive substrate at the anode side by the EPD. They showed yellow fluorescence of the QDs. The thickness increased with increasing the deposition time; however, hemispherical holes attributed to oxygen gas generated by water electrolysis were observed at the longer time. The electron microscopy revealed that the films were densely and homogeneously deposited. The QDs were dispersed around the resin nanoparticles without aggregation. The fluorescence (FL) quantum yield was 43%. The optical absorption peak and FL intensity of the QDs increased accompanied by the film growth. The nanocomposite film showed good heat resistance at 80-120 °C for 5 h; therefore, the prepared films have feasibility in white light-emitting diode (LED) applications. A lightening device structured with the obtained EPD film placed on a blue LED successfully emitted white light. In addition, the flexibility of the nanocomposite film was demonstrated. The aqueous EPD method would be one of the suitable methods for the industrial production of fluorescent QD films. This technique can be applied to other hydrophilic fluorescent QDs with charged surfaces. Realization of various fluorescent QD films would expand the application possibilities.

Time-Resolved Dynamics of Metal Halide Perovskite under High Pressure: Recent Progress and Challenges.

Metal halide perovskites have garnered significant attention in the scientific community for their promising applications in optoelectronic devices. The application of pressure engineering, a viable technique, has played a crucial role in substantially improving the optoelectronic characteristics of perovskites. Despite notable progress in understanding ground-state structural changes under high pressure, a comprehensive exploration of excited-state dynamics influencing luminescence remains incomplete. This Perspective delves into recent advances in time-resolved dynamics studies of photoexcited metal halide perovskites under high pressure. With a focus on the intricate interplay between structural alterations and electronic properties, we investigate electron-phonon interactions, carrier transport mechanisms, and the influential roles of self-trapped excitons (STEs) and coherent phonons in luminescence. However, significant challenges persist, notably the need for more advanced measurement techniques and a deeper understanding of the phenomena induced by high pressure in perovskites.

Electronic, optical, and transport properties of boron arsenide monolayers tailored with hydrogenation and halogenation

In this study, density functional theory was used to demonstrate the effectiveness of a strategy involving chemical functionalization, specifically hydrogenation and halogenation, to tailor the electronic, optical, and transport properties of boron arsenide (BAs) monolayer. Compared to the half-functionalized BAs monolayers, the fully functionalized BAs monolayers (X–BAs–X, X = H, F, Cl, Br, and I) showed excellent stability. Moreover, functionalization not only disrupted the planar structure of BAs monolayer but also broke its mirror symmetry, enabling effective modulation of its bandgap and work function within the ranges of 0.29 eV–4.25 eV and 3.96 eV–6.98 eV, respectively. In addition, functionalization significantly enhanced optical absorption in the infrared and ultraviolet regions and induced the notable negative differential resistance effect in transmission devices. Thus, functionalization offers a versatile means for modulating the electronic, optical, and transport properties of BAs monolayers, thereby expanding their potential applications in optoelectronic and microelectronic devices.

Ultrafast acousto-optic modulation at the near-infrared spectral range by interlayer vibrations

Abstract The acousto-optic modulation over a broad near-infrared (NIR) spectrum with high speed, excellent integrability, and relatively simple scheme is crucial for the application of next-generation opto-electronic and photonic devices. This study aims to experimentally demonstrate ultrafast acousto-optic phenomena in the broad NIR spectral range of 0.77–1.1 eV (1130–1610 nm). Hundreds of GHz of light modulation are revealed in an all-optical configuration by combining ultrafast optical spectroscopy and light–sound conversion in 10–20 nm-thick bismuth selenide (Bi2Se3) van der Waals thin films. The modified optical transition energy and the line shape in the NIR band indicate phonon–photon interactions, resulting in a modulation of optical characteristics by the photoexcited interlayer vibrations in Bi2Se3. This all-optical, ultrafast acousto-optic modulation approach may open avenues for next-generation nanophotonic applications, including optical communications and processing, due to the synergistic combination of large-area capability, high photo-responsivity, and frequency tunability in the NIR spectral range.

Effects of different atomic passivation on conductive and dielectric properties of silicon carbide nanowires

Based on the transport and polarization relaxation theories, the effects of hydrogen, fluorine, and chlorine atom passivation on the conductivity and dielectric properties of silicon carbide nanowires (SiCNWs) were numerically simulated. The results show that passivation can decrease the dark conductivity of SiCNWs and increase its ultraviolet photoconductivity. Among them, the photoconductivity of univalent (H) passivated SiCNWs is better than that of seven-valent (Cl, F) passivated SiCNWs. In terms of dielectric properties, the passivated SiCNWs exhibit a strong dielectric response in both deep ultraviolet and microwave regions. Hydrogen passivation SiCNWs produce the strongest dielectric response in deep ultraviolet, while fluorine passivation SiCNWs produce the strongest dielectric relaxation in the microwave band, which indicates that atomic passivation SiCNWs have a wide range of applications in ultraviolet optoelectronic devices and microwave absorption and shielding.

Defects in layered boron nitride grown by Metal Organic Vapor Phase Epitaxy: luminescence and positron annihilation studies

Defects in two-dimensional boron nitride (BN) are candidates for a manifold of applications, for example, as single-photon emitters or optically addressable spin defects. However, the topic has proven to be complex and despite extensive research efforts, knowledge on midgap defects and their signature in photoluminescence (PL) remains fragmentary. Mass production of high-quality layered BN by Metal Organic Vapor Phase Epitaxy (MOVPE) is possible and effective, thus understanding the conditions of formation and identifying defects that arise in the material grown by this method is extremely important. Here, we present an analysis of the influence of the MOVPE growth conditions of layered BN on the occurrence of specific structural defects. PL spectra in the visible range were analysed involving the Huang-Rhys theory implemented in the fitting procedure for polycrystalline samples grown under various conditions. Such an approach allowed us to separate bands from individual entities. Two bands at 1.57 eV and 2.6 eV with phonon replicas were observed. The three additional bands are characterized by a broad emission centered at 1.38 eV, 1.9 eV and 2.24 eV. Further properties, including an analysis of the surface morphology, the impact of annealing and laser bleaching on the PL spectra and Positron Annihilation Spectroscopy (PAS) were considered to draw conclusions about the nature of the examined defects. The PAS analysis correlated with the PL of the BN layers allows us to classify the studied samples in terms of the concentrations of boron vacancies and their complexes. Based on the obtained results, we propose that the rich family of PL bands observed in various sp2-BN layers is associated with different defect complexes build of boron vacancies (VB), boron antisite defects (BN), substitutional carbon defects (CB, CN) and their donor-acceptor pairs. The main value of this paper is the transfer of knowledge gained about defects and the corresponding luminescent bands to characterize high-quality continuous epitaxial sp2-BN layers. The presented results constitute an important step toward the deterministic manipulation of defect concentrations in two-dimensional boron nitride, which opens up new pathways for future optoelectronic device application.

Solar-blind ultraviolet photodetector based on Nb2C/β-Ga2O3 heterojunction

β-Ga2O3 has been widely investigated for its stability and thermochemical properties. However, the preparation of β-Ga2O3 thin films requires complex growth techniques and high growth temperatures, and this has hindered the application of β-Ga2O3 thin films. In this study, β-Ga2O3 thin films with good crystalline quality were prepared using a green method, and an ultraviolet (UV) detector based on β-Ga2O3 with a photocurrent of 2.54 × 10–6 A and a dark current of 1.19 × 10–8 A has been developed. Two-dimensional materials have become premium materials for applications in optoelectronic devices due to their high conductivity. Here, we use the suitable energy band structure between Nb2C and Ga2O3 to create a high carrier migration barrier, which reduces the dark current of the device by an order of magnitude. In addition, the device exhibits solar-blind detection, high responsiveness (28 A W−1) and good stability. Thus, the Nb2C/β-Ga2O3 heterojunction is expected to be one of the promising devices in the field of UV photoelectric detection.

Impact of transparent conducting substrates on structural and optical of Titanium(IV) phthalocyanine dichloride (TiPcCl2) thin films

This study investigates the impact of transparent conducting substrates, specifically indium-doped tin oxide (ITO) and fluorine-doped tin oxide (FTO), on the structural and optical characteristics of thermally evaporated Titanium phthalocyanine chloride (TiPcCl2) thin films. The crystalline structure of TiPcCl2/quartz thin films was verified by X-ray powder diffraction (XRD) patterns while amorphous phases were detected in TiPcCl2/ITO and TiPcCl2/FTO thin films. Field emission scanning electron microscopy (FESEM) images provided evidence that the morphology of TiPcCl2 thin films may be affected by a lattice mismatch between TiPcCl2 and substrates. Fourier-transform infrared spectroscopy (FT-IR) also showed that the substrates did not change the molecular structure of TiPcCl2. UV–Vis-NIR spectroscopy demonstrated that the substrates had a significant influence on the optical gap, optical constants, dielectric constant dielectric loss functions and optical conductivity of TiPcCl2 thin films. Lastly, the nonlinear susceptibility χ(3), the nonlinear refractive index n2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\\varvec{n}}}_{2}$$\\end{document} and the nonlinear absorption coefficient β(c) for TiPcCl2/ITO, TiPcCl2/FTO, and TiPcCl2/quartz were obtained using a semi-empirical approach. The changes seen in optical properties could be due to changes in the crystal structure and morphology, which are closely connected to the properties of the substrate material. Overall, the results for TiPcCl2 thin films are promising, and they are appropriate for novel optoelectronic device applications.

Air-Stable, Large-Area 2D Metals and Semiconductors.

Two-dimensional (2D) materials are popular for fundamental physics study and technological applications in next-generation electronics, spintronics, and optoelectronic devices due to a wide range of intriguing physical and chemical properties. Recently, the family of 2D metals and 2D semiconductors has been expanding rapidly because they offer properties once unknown to us. One of the challenges to fully access their properties is poor stability in ambient conditions. In the first half of this Review, we briefly summarize common methods of preparing 2D metals and highlight some recent approaches for making air-stable 2D metals. Additionally, we introduce the physicochemical properties of some air-stable 2D metals recently explored. The second half discusses the air stability and oxidation mechanisms of 2D transition metal dichalcogenides and some elemental 2D semiconductors. Their air stability can be enhanced by optimizing growth temperature, substrates, and precursors during 2D material growth to improve material quality, which will be discussed. Other methods, including doping, postgrowth annealing, and encapsulation of insulators that can suppress defects and isolate the encapsulated samples from the ambient environment, will be reviewed.

Tin-based perovskite films fabricated by chemical vapor deposition for photodetector application

Tin-based perovskite materials have shown great potential applications in environment-friendly optoelectronic devices. However, it is difficult to control the film growth process by solution method due to the rapid formation speed of the film. In this work, tin-based perovskite (FASnI3) films were prepared by chemical vapor deposition method. The film is mainly composed of thin nanoplates when the deposition temperature is 600 °C. The film shows good antioxidant properties by comparing the ratio between Sn4+ and Sn2+. Time-resolved fluorescence imaging measurements clearly reveal the fluorescence lifetime inhomogeneity in the film. The photodetectors based on tin-based perovskite films show good photo response properties, with a switching ratio of 808. This work provides new opportunities for non-lead perovskite thin film preparation and optoelectronic application.

Enhanced optical third-harmonic generation in phase-engineered nanostructured Zn1−x Cd x S thin films for optoelectronic device applications

A polycrystalline nanostructured thin film of zinc cadmium sulfide was meticulously fabricated on a glass substrate using the thermal evaporation method physical vapor deposition within a vacuum chamber. Different doping concentrations were introduced by varying the cadmium (Cd) content, resulting in Zn1-x Cd x S films with Cd concentrations ranging from x = 0.00–0.20 wt %. The impact of Cd doping on the third-order nonlinear optical (TONLO) properties of these films was thoroughly studied using the Z-scan method, employing a diode-pumped solid-state continuous-wave laser. To gain insight into the structural characteristics, the Zn1-x Cd x S thin films underwent analysis through x-ray diffraction. Optical studies confirmed the tunability of the optical band gap (Eg) in the Zn1-x Cd x S films, ranging from 3.88 eV for undoped ZnS to 2.80 eV for the film fabricated with 20 wt. % of Cd-content. This significant reduction in ‘Eg’ renders the films highly suitable for use as absorbing layers in applications such as solar cells and optoelectronics. Surface morphology analysis, performed via field emission scanning electron microscopy, revealed noticeable alterations with increased Cd doping. Significantly, the doped films exhibited a substantial redshift in the band edge and an increase in transmittance within the visible and near-infrared regions. The investigation of TONLO properties, including the nonlinear absorption coefficient (β), nonlinear refractive index (n 2) and susceptibility χ(3), yielded values ranging from 3.15 × 10−3 to 8.16 × 10−3 (cm W−1), 1.65 × 10−8 to 7.45 x 10–8 (cm2 W−1), and 3.12 × 10−5 to 7.86 × 10−5 (esu), respectively. These results indicate the presence of self-defocusing nonlinearity in the films. Overall, the outcomes underscore the potential of Cd-doped ZnS nanostructures in modifying surface morphology and enhancing NLO characteristics. Zn1-x Cd x S thin films exhibit promise for applications in nonlinear optical devices, as evidenced by these encouraging findings.

Surface‐Initiated Living Self‐Assembly of Polythiophene‐Based Conjugated Block Copolymer into Erect Micellar Brushes

AbstractNanostructured conjugated polymers are of widespread interest due to their broad applications in organic optoelectronic devices, biomedical sensors and other fields. However, the alignment of conjugated nanostructures perpendicular to a surface remains a critical challenge. Herein, we report a facile method to directly self‐assemble a poly(3‐(2‐ethylhexyl)thiophene), P3EHT‐based block copolymer into densely aligned micellar brushes through surface‐initiated living crystallization‐driven self‐assembly. The presence of an ethyl pendant on the side group intrinsically moderates the crystallization rate of the polythiophene main chains, and hence favors the controlled living growth of long conjugated fibers and the subsequent fabrication of conjugated micellar brushes. The corona of the micellar brush can be further decorated with platinum nanoparticles, which enables the formation of erect nanoarrays with heights up to 2700 nm in the dried state. This also renders the micellar brush catalytically active toward hydrogen evolution reaction, which shows a low overpotential of 27 mV at 10 mA cm−2. Notably, the P3EHT‐based micellar brush can simultaneously grow with polyferrocenyldimethylsilane, PFS‐based micellar brush on the same surface without any significant interference between the two systems. Thus, these two micellar brushes can be patterned through site‐selective immobilization of two types of seeds followed by independent living self‐assembly.

Surface-Initiated Living Self-Assembly of Polythiophene-Based Conjugated Block Copolymer into Erect Micellar Brushes.

Nanostructured conjugated polymers are of widespread interest due to their broad applications in organic optoelectronic devices, biomedical sensors and other fields. However, the alignment of conjugated nanostructures perpendicular to a surface remains a critical challenge. Herein, we report a facile method to directly self-assemble a poly(3-(2-ethylhexyl)thiophene), P3EHT-based block copolymer into densely aligned micellar brushes through surface-initiated living crystallization-driven self-assembly. The presence of an ethyl pendant on the side group intrinsically moderates the crystallization rate of the polythiophene main chains, and hence favors the controlled living growth of long conjugated fibers and the subsequent fabrication of conjugated micellar brushes. The corona of the micellar brush can be further decorated with platinum nanoparticles, which enables the formation of erect nanoarrays with heights up to 2700 nm in the dried state. This also renders the micellar brush catalytically active toward hydrogen evolution reaction, which shows a low overpotential of 27 mV at 10 mA cm-2 . Notably, the P3EHT-based micellar brush can simultaneously grow with polyferrocenyldimethylsilane, PFS-based micellar brush on the same surface without any significant interference between the two systems. Thus, these two micellar brushes can be patterned through site-selective immobilization of two types of seeds followed by independent living self-assembly.

Nanocomposites comprising PVA/CMC matrix and CNTs/Fe2O3 nanohybrid: A comparative investigation of structural, optical, electrical, and dielectric properties as an application in advanced electrochemical and optoelectronic devices

This work addresses the fabrication of innovative flexible polymer nanocomposite films for electrochemical products made of poly (vinyl alcohol) (PVA), carboxymethyl cellulose (CMC), multi-walled carbon nanotubes (CNTs), and hematite (α-Fe2O3) nanoparticles (NPs) as nanohybrid. The PVA/CMC-CNTs/Fe2O3 nanocomposite films were characterized using various approaches. The PVA/CMC blend polymer matrix shows significant improvements in terms of amorphous nature with the CNTs/Fe2O3 nanofiller content, resulting in an exceedingly flexible polymer backbone and with higher ionic conductivity of the PVA/CMC-CNTs/Fe2O3 nanocomposites films, as reported by the XRD examination. The nanoparticle surfaces and the blend matrix exhibit a significant interaction, as seen by the FTIR spectra. To learn more about how CNTs/Fe2O3 NPs affect the optical characteristics of the PVA/CMC, its optical characteristics were examined. The absorption edge appeared to migrate towards lower photon energy sides upon the addition of CNTs/Fe2O3 NPs to the PVA/CMC matrix. The Eg (direct and indirect) of pure PVA/CMC was considerably decreased from 5.12 to 3.55 eV and 4.23 to 3.01 eV respectively by adding 3.5 wt% of CNTs/Fe2O3 NPs. The results proved the influence of the nanofiller on the host polymer's decreased band gap energy. The blend nanocomposite had a substantially higher AC conductivity compared with the blend, and the PVA/CMC-3.5%CNTs/Fe2O3 nanocomposite had the highest electrical conductivity. It was discovered that while the dielectric loss and dielectric constant increased with the high content of nanoparticles, they reduced with increasing frequency. These findings demonstrated that the produced films had undergone substantial changes, which allows for the use of flexible films made of PVA/CMC-CNTs/Fe2O3 in a variety of electrochemical and optoelectronic applications.

Effect of high concentration of ZnO on the structural and optical properties of silicate glass system

An investigation was conducted to explore the optimum composition to fabricate a zinc silicate glass substrate for optoelectronic device applications. The composition was determined based on the empirical formula (ZnO)x-(SiO2)1-x, where x = 0.40, 0.50, 0.60 and 0.70 wt%, which was prepared by the conventional melt quenching technique. The focus is on characterizing the physical and structural aspects as well as the optical properties of the glass substrate. The physical properties of zinc silicate samples were assessed using the densitometer and their physical appearance. In addition, the materials' amorphous and glassy characteristics were verified using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques. Finally, ultraviolet–visible (UV–Vis) spectroscopy and photoluminescence spectrometer were used to study the optical properties of samples. The density of the samples was observed to increase from 2805 to 3878 kg/m3 as the percentage of ZnO in the glass composition increased. X-ray diffraction analysis indicated the absence of sharp peaks in the samples containing up to 0.60 wt% of ZnO, suggesting the presence of an amorphous phase. Furthermore, the results of this study indicate that ZnO-SiO2 glass substrate samples favor direct forbidden transitions, with an increase in ZnO leading to higher absorption and consequently a lower band gap. The photoluminescence spectrum showed blue light emissions at 422 nm, associating with the variation of band gaps in the ZnO phase. Overall, from the interesting results achieved, this zinc silicate-based composite material at 0.60 wt% ZnO can be a potent candidate in optoelectronic applications, among other concentrations used in this study.