Applications In Optical Devices Research Articles

Investigations of the physical behavior of Cr2PX (X = C and N) MAX phases through first-principles calculations

MAX phases display an exclusive combination of ceramic and metallic characteristics, which makes them highly promising for various technological applications. This study investigated MAX phases of 211-type based on Cr2PX (X = C and N) by focusing on their physical properties, mainly the magnetic, electronic, and optical behaviors. The results obtained using the “density functional theory (DFT) based full-potential linearized augmented plane wave (FP-LAPW) method” matched those reported in the literature, indicating the reliability of the adopted methodology. The stabilities of the Cr2PX were validated by calculating their cohesive energies and phonon band structures. These compounds demonstrate identical energies for nonmagnetic, ferromagnetic, and antiferromagnetic phases and exhibit symmetrical arrangements of the “density of states (DOS)” for both up and down spins. Moreover, these MAX phases exhibit high optical absorption (∼10−6cm−1) and anisotropic reflectivity spectra, emphasizing the role of crystallographic orientation and their potential for applications in photovoltaics and other optical devices. These findings will provide valuable insights into the properties and behaviors of Cr2PX-based 211-MAX phases, thereby establishing the foundation for further research and potential applications across diverse areas.

Synthesis and Luminescence Studies of Tb3+-Doped Li2CaSiO4 Phosphor for Optical Device Application

Synthesis and Luminescence Studies of Tb3+-Doped Li2CaSiO4 Phosphor for Optical Device Application

Interaction of highly focused intense laser radiation with transparent dielectrics: Subwavelength nanogratings formation

Femtosecond laser writing of birefringent subwavelength nanolattices in dielectrics has been studied for almost two decades since it reveals a number of applications for optical memory devices, optical waveguides, microfluidic channels, etc. In this work, a numerical study of the formation of plasma quasiperiodic nanostructures in a fused silica in the propagation direction of a focused laser pulse is carried out. It is shown that the focused beam creates a dense plasma, which provides an effective reflection of the incident laser pulse, leading to the formation of a standing wave. In the bundles of standing wave, an effective ionization emerges, which forms plasma gratings with a subwavelength period. The conducted modeling allows us to determine the conditions under which the proposed regime of material nanostructuring is possible. It is shown that the energy absorbed in plasma gratings will ensure the substance melting, which leads to the formation of “frozen” quasiperiodic nanopatterns.

Structural, morphological, optical and electrical characterization of MgO thin films grown by sputtering technique on different substrates

Magnesium Oxide (MgO) thin film structures were deposited on glass and n-Si substrates by means of RF magnetron sputtering technique. Structural, morphological, optical characteristics of MgO thin film were determined by XRD, AFM and UV–Vis spectrometer techniques. The optical properties like absorption coefficient and optical band gap were extracted using optical transmittance and absorption spectra. The band-gap of MgO thin film was determined for direct electronic transition. Additionally, electric parameters like ideality factor, saturation current and barrier height of the Au/MgO/n-Si device were computed from the forward I–V data in dark state. The ideality factor was found to be greater than one. This indicates that the I–V characteristics of the device exhibits non-ideal attitude. The results show that the MgO thin film can be applied to both optical and electronic device applications.

Automated design of hybrid halide perovskite monolayers for band gap engineering

The recent experimental confirmation of perovskite monolayers has sparked ongoing efforts in their prediction and synthesis, showcasing their flexible tunable band gap and potential in advanced functional devices. Although large-scale computational designs have been successfully performed for inorganic perovskite monolayers, the complexity introduced by organic cations hinders the same approaches applied to the hybrid halide perovskite monolayers. To address this challenge, we have proposed a high-throughput first-principles computational workflow that automates the design of hybrid halide perovskite monolayers. We strategically reduce the complexity of the configurations by analyzing the orientation of cations and the structural symmetry. Over 400 hybrid halide perovskite monolayers have been designed, and their structures and fundamental properties are stored in the database. Correlation analyses show a strong correlation between band gaps and metal-halogen-metal bond angles or metal-halogen bond lengths, consistent with prior studies for bulk and layered perovskites. The underlying physics that the band gap is modulated by the antibonding in the metal-halogen bond makes band gap engineering of hybrid halide perovskite monolayers feasible. Accordingly, initial research on lateral heterojunctions and solar cells has been conducted to explore the potential practical applications of the designed hybrid halide perovskite monolayers. Our study lays the foundation for further exploration of hybrid halide perovskite monolayers and highlights promising opportunities for their potential applications in electronic and optical devices.

A photoluminescent elastomer with high toughness and fast self-healing behavior enabled by crosslinking polyurethane with reactive lanthanide complex

The synthesis of luminescent self-healing materials together with outstanding comprehensive mechanical features is yet a significant challenge due to the contradictory relationship between the self-healing features and mechanical characteristics. In this work, a lanthanide-based photoluminescent elastomer exhibiting super toughness and fast self-healing behavior was prepared via first synthesizing a photoluminescent complex and then utilizing which as the effective functional cross-linkers. The complexes were synthesized with p-aminobenzoic acid and 1,10-Phenanthroline as ligands, Ln3+ as the central luminescent ions. The backbone of the polymers was obtained by the polymerization of tolylene-2,4-diisocyanate-terminated polypropylene glycol (PPG-NCO) and isophorone diamine (IPDA). The addition of the complex as a cross-linking agent increases the degree of cross-linking of the polymer chains, and endows the material with good mechanical properties. In addition, self-healing properties was achieved thanks to the dynamic synergistic effect of Ln3+-ligand bonding and inter-amide hydrogen bonding. Furthermore, by varying the molar ratio of Eu3+/Tb3+, multi-color emission which ranging from red to green, has been accomplished. We are confident that the method employed in this study offers a little inspiration on the preparation of toughened luminescent products with self-healing features, which have wide ranging of applications in flexible optical devices, advanced information encryption, and other fields.

Tuning the optical properties of transparent ZIF-8 thin films by adjusting the crystal morphology

Optical properties are the most significant properties of optical thin films, which determine its application in optical and photoelectric devices. Designable optical properties are the most challenging goals in optical material engineering. Recently, Metal-organic framework (MOF)-based optical thin films have attracted increasing attention due to their novel optical properties, especially their modular design, which allows fine-tuning of the relevant properties. In this work, a strategy for tuning the optical properties of MOF-based thin films is developed, which is realized by adjusting MOF crystal morphology. A commonly used MOF, ZIF-8 (zeolitic imidazolate framework-8), is selected as the research model. The morphology of ZIF-8 nanocrystal is adjusted using a surfactant/end-capping agent modulation method. The surfactant/end-capping agents are absorbed onto different crystal planes of ZIF-8, slowing the growth of the crystal planes and causing the formation of ZIF-8 crystals with different morphologies. Six different morphologies of ZIF-8 crystals are successfully synthesized in the presence of different amounts of CTAB and/or TRIS: nano-spherical, rhombohedral dodecahedron, nano-cubic, rough octahedron, flake-shaped and hexapod-like morphology. Then, the corresponding ZIF-8 thin films with different crystal morphologies are prepared via spin-coating. The optical properties of the thin films are investigated using UV–vis spectroscopy and ellipsometry in detail. The results indicate that the film with rough octahedron morphology has the best transmittance, reaching 93.35 % at 581 nm. As a key optical parameter of the film, its refractive index can be adjusted between 1.27 and 1.54. The success of tuning of the optical properties of MOF optical thin films by adjusting the crystal morphology will make it meet the different required optical properties in various optical and photoelectric devices.

In situ formation of silver nanoparticles within labradorite mineral crystals exhibiting third-order nonlinearity

Silver nanoparticles are cost-effective plasmonic materials for the nonlinear optics, but the applications suffer incompatibility with the matrices. This study explores the in situ formation of silver nanoparticles within the crystalline matrix of labradorite minerals. The methodology involves a high-temperature diffusion process, enabling the nucleation and growth of silver nanoparticles directly within the labradorite crystal lattice. Characterization through spectroscopic and microscopic techniques reveals the successful formation of silver nanoparticles with a diameter of 8.40 ± 4.32 nm, exhibiting notable surface plasmonic resonances absorption at 414 nm. Additionally, the nonlinear optical property of the resulting material is investigated through Z-scan experiments. The third-order nonlinear optical susceptibility β at 400 nm was estimated to be 5.0 × 10−12 m/W. This research not only advances our understanding of nanoscale phenomena within mineral crystals but also underscores their potential applications in nonlinear optical devices and related fields.

Preparation of In0.5Sn0.5Se Crystal via a Zone Melting Method and Evaluation of its Thermoelectric Properties

AbstractIndium selenides (InSe) is a promising layer‐structured semiconductor with broad potential applications in photovoltaics, diodes, and optic devices, but its thermoelectric performance is limited by the high thermal conductivity. In this work, by alloying high‐performance thermoelectric SnSe in InSe, the In0.5Sn0.5Se crystal is prepared via a zone melting method. The density of In0.5Sn0.5Se crystal is measured as 5.81 g cm−3 which is between the density of pure SnSe and InSe. The XRD measurements indicate that the grown In0.5Sn0.5Se crystal consists of InSe and SnSe crystals with a preferred orientation along (00l) and (h00) planes, respectively. SEM and EDS analysis reveal that eutectic InSe and SnSe phases interdigitate with each other. The thermogravimetry analysis shows a slow decrease at a temperature ≈700 °C. In0.5Sn0.5Se crystal displays a n‐type conduct behavior, the electrical conductivity σ is ≈0.02 Scm−1 at room temperature and increases to 8.4 Scm−1 under 820 K. The highest power factor PF is estimated to be ≈0.36 µWcmK−2 near 570 K. The InSe‐SnSe phase boundaries lead the thermal conductivity of In0.5Sn0.5Se crystal to be as low as 0.29 Wm−1K−1. Due to the low lattice thermal conductivity, In0.5Sn0.5Se crystal shows a ZT value of 0.04 at 600 K in this work.

Nonlinear Optical Saturable Absorption Properties of 2D VP Nanosheets and Application as SA in a Passively Q-Switched Nd:YVO4 Laser.

Two-dimensional (2D) violet phosphorus (VP) plays a significant role in the applications of photonic and optoelectronic devices due to its unique optical and electrical properties. The ultrafast carrier dynamics and nonlinear optical absorption properties were systematically investigated here. The intra- and inter-band ultrafast relaxation times of 2D VP nanosheets were measured to be ~6.83 ps and ~62.91 ps using the pump-probe method with a probe laser operating at 1.03 μm. The nonlinear absorption coefficient βeff, the saturation intensity Is, the modulation depth ΔR, and the nonsaturable loss were determined to be -2.18 × 104 cm/MW, 329 kW/cm2, 6.3%, and 9.8%, respectively, by using the Z-scan and I-scan methods, indicating the tremendous saturable absorption property of 2D VP nanosheets. Furthermore, the passively Q-switched Nd:YVO4 laser was realized with the 2D VP nanosheet-based SA, in which the average output power of 700 mW and the pulse duration of 478 ns were obtained. These results effectively reveal the nonlinear optical absorption characteristics of VP nanosheets, demonstrating their outstanding light-manipulating capabilities and providing a basis for the applications of ultrafast optical devices. Our results verify the excellent saturable absorption properties of 2D VP, paving the way for its applications in pulsed laser generation.

Fabrication, surface characterization and effect of oxygen irradiation on polymeric nanocomposite films

This study addressed the preparation of nanocomposites consisting of polyvinyl alcohol (PVA) and titanium oxide (TiO2) for utilization in optoelectronics technologies. PVA/10%TiO2 nanocomposite samples with a mean thickness of 0.1[Formula: see text]mm were created using the solution casting method. The PVA/TiO2 films are irradiated with oxygen fluences of [Formula: see text], [Formula: see text] and [Formula: see text] ions/cm2. The X-ray diffraction (XRD) and FTIR methodologies were employed to investigate the impact of ion bombardment on the structural characteristics and functional groups of PVA/TiO2 substrates. Diffraction peaks are 20.1° for PVA and 25.4° for TiO2, indicating the successful PVA/TiO2 nanocomposite construction. The absorbance (A) of unirradiated and irradiated samples was measured using UV–Vis spectroscopy within a wavelength range of 200–1100[Formula: see text]nm. Band gaps ([Formula: see text]) were calculated using Tauc’s formula for PVA/TiO2 films, exhibiting a decrease from 4.56[Formula: see text]eV for unirradiated PVA/TiO2 film to 4.16, 3.95 and 3.88[Formula: see text]eV at ion fluences of [Formula: see text], [Formula: see text] and [Formula: see text] ions/cm2, respectively. Furthermore, the Ubrach tail has a rise of 1.23[Formula: see text]eV for unirradiated PVA/TiO2 to 1.28[Formula: see text]eV, 1.4[Formula: see text]eV and 1.77[Formula: see text]eV for irradiated films with ion fluences of [Formula: see text], [Formula: see text] and [Formula: see text] ions/cm2, respectively. Additionally, following ion irradiation, the PVA/TiO2 absorption edge [Formula: see text], which was 3.56[Formula: see text]eV, decreased to 3.48, 3.37 and 3.23[Formula: see text]eV, with increasing ion beam fluences. This study demonstrated that the optical behaviors of the PVA/TiO2 films were altered under bombardment, suggesting their potential applicability in optical devices.

Fabrication of pbs films for air mass filter of solar simulator

The production of solar panels is continuously increasing due to increasing demands at industrial and residential levels. This also leads to an increasing demand for solar simulator testing tools. A solar simulator is a tool to assess a solar panel's performance in lab and industry scales. One of the main components of the solar simulator is the Air Mass Filter (AMF). The primary function of AMF is to remove unwanted wave bands from the solar simulator light source (e.g., Xe arc lamp) so that the filtered spectrum is commensurate to that of solar irradiation. An AMF can be produced by fabricating a thin material layer on a transparent substrate like glass. The film would absorb certain wave bands in different ways. This paper reports the fabrication of the chalcogenide PbS thin films for applying AMF. The thermal evaporation technique is used for the film fabrication. PbS is known for its versatility for applications in different optical devices due to its tailorable optical properties. Different amounts (in grams) of PbS source powders are used to deposit the PbS thin films. The optical properties of the films are then examined using UV-Vis spectroscopy. The distributions of the transmittance intensity of the Xe-arc-lamp light with and without the use of the films as an optical filter are then examined using a solar simulator. From the experiments, the film deposited using a 0.012 g PbS powder source is regarded as the optimum one regarding the transmittance intensity distribution.

Ab initio calculation of electronic and optical properties of vdWHs HfX2/BSb(X = Se,S) using density functional theory

Recently, another series of two-dimensional (2D) materials called van der Waals heterostructures (vdWhs) have attracted a lot of attention due to their outstanding properties and wide application in electronic and optical devices. Based on density functional theory (DFT) calculations, the properties of heterostructures were investigated with two different vertical arrangements, formed by two isolated sheets of HfX2(X = Se,S) and Boron antimonide(BSb) monolayer. In particular, vdW interactions are present in all these heterostructures rather than covalent bonding. All thevdWHsare semiconductor with indirect k-M band gap, for which the HSE06 functional exhibit a larger gap, but the electronic gap of all heterostructures is smaller than the electronic gap of their constituent sheets. In addition, all vdWHs show excellent optical absorption in the visible, near-infrared, and ultraviolet regions in the x direction, while the absorption peaks for all vdWHs are higher in the z direction. By fabricating heterostructures from isolated plates, their absorption power increases. The present review demonstrates an effective method for the design of novel vdWHs, and it explores their applications for photocatalytic, photovoltaic, and optical devices.

Theoretical investigation of bidirectional and unidirectional dual-band absorption in one dimensional Octonacci sequences controlled by Dirac semimetal and Vanadium dioxide

The dual-band absorption properties of one-dimensional ternary Octonacci sequences, comprising dielectric, Dirac semimetal (DS), and Vanadium dioxide (VO2), are investigated theoretically and numerically using transfer matrix method, full-wave simulations, and impedance match theory. The photonic quasi-periodic multilayers exhibit bidirectional dual-band high absorption properties, attributed to strong electric field localization. Interestingly, this dual-band absorption can be spectrally tuned to the desired frequencies by adjusting the Fermi energy of the DS, changing the structure's parameters, the choice of dielectric, and the angle of incidence. Furthermore, the addition of a VO2 layer at the bottom of the Octonacci sequence enables the realization of dynamically tunable bidirectional and unidirectional dual-band absorption by modulating the conductivity of VO2. Remarkably, the absorption response remains insensitive to the polarization of the incident wave. These unique properties, together with the ease of manufacturing, make our proposed structures a promising candidate for wide applications in tunable optical devices.

Fundamentals and emerging optical applications of hexagonal boron nitride: a tutorial

Hexagonal boron nitride (hBN), also known as white graphite, is a transparent layered crystal with a wide bandgap. Its crystal structure resembles graphite, featuring layers composed of honeycomb lattices held together through van der Waals forces. The layered crystal structure of hBN facilitates exfoliation into thinner flakes and makes it highly anisotropic in in-plane and out-of-plane directions. Unlike graphite, hBN is both insulating and transparent, making it an ideal material for isolating devices from the environment and acting as a waveguide. As a result, hBN has found extensive applications in optical devices, electronic devices, and quantum photonic devices. This comprehensive tutorial aims to provide readers with a thorough understanding of hBN, covering its synthesis, lattice and spectroscopic characterization, and various applications in optoelectronic and quantum photonic devices. This tutorial is designed for both readers without prior experience in hBN and those with expertise in specific fields seeking to understand its relevance and connections to others.

Investigation of structural, electronic, optical and thermoelectric properties of hallide double perovskite Rb2AlAgX6 (X = Cl, I): A first-principles DFT study

In order to meet the demands of the energy consumption, double perovskites (DP) are a dependable green energy source. Consequently, there is a great deal of promise for thermoelectric and optoelectronic device applications when studying these perovskite halides. Our work examined the thermoelectric and optoelectronic properties of Rb2AlAgCl6 and Rb2AlAgI6 halides using Density Functional Theory (DFT). The tolerance factor and energy of formation for the halides that were examined show that they are stable in the cubic phase, structurally and thermodynamically. We calculated the bandgaps for Rb2AlAgCl6 (Eg = 3.82 eV) and Rb2AlAgI6 (Eg = 1.321 eV) using mBJ potentials, and compared them to the reported values. The optical characteristics of the materials under investigation were revealed through the use of a complicated dielectric function. The computed optical findings show that the materials are suitable for optoelectronic applications, with maximal light absorption occurring in the ultraviolet (UV) and infrared (IR) ranges. Optical parameters obtained includes large values of absorption coefficients (∼105cm−1), low reflectivity (∼1–15 %), and high optical conductivity (∼1015 sec−1). Thermoelectric properties revealed enhanced power factor for Rb2AlAgI6 as compared to Rb2AlAgCl6. These results imply that these materials are appropriate for application in optical and thermoelectric devices.

Controlled growth of 3R phase niobium diselenide and its properties

Inversion symmetry broken 3R phase transition metal dichalcogenides (TMDs) show fascinating prospects in spintronics, valleytronics, and nonlinear optics. However, the controlled synthesis of 3R phase TMDs is still a great challenge. In this work, two-dimensional 3R-NbSe2 single crystals up to 0.2 mm were synthesized for the first time through chemical vapor deposition method by designing a space-confined system. The crystal size and morphology can be controlled by the location of the stacked substrates and the amount of the Nb2O5 precursor. Scanning transmission electron microscopy and Raman measurements reveal the NbSe2 exhibits a pure 3R stacking mode with relatively weak interlayer van der Waals interactions. Importantly, 3R-NbSe2 shows obvious second harmonic generation signal which intensity intensified as thickness increases. Density functional theory calculations and optical absorption demonstrate the coexistence of metallic and semiconducting optical properties of 3R-NbSe2. We designed a NbSe2/WS2/NbSe2 photodetector utilizing the metallicity of 3R-NbSe2, which shows good performance especially an ultrafast response (6–7 μs, 0.5 ms − 7.9 s for Au electrodes in literature). The proposed strategy and findings are of great significance for the growth of many other 3R-TMDs and applications of nonlinear optical and ultrafast devices.

A Tunable Hydrophilic-Hydrophobic, Stimulus Responsive, and Robust Iridescent Structural Color Bionic Film with Chiral Photonic Crystal Nanointerface.

Bio-inspired in nature, using nanomaterials to fabricate the vivid bionic structural color and intelligent stimulus responsive interface as smart skin or optical devices are widely concerned and remain a huge challenge. Here, the bionic flexible film is designed and fabricated with chiral nanointerface and tunable hydrophilic-hydrophobic by the ultrasonic energy perturbation strategy and crosslinking of the cellulose nanocrystals (CNC). An intelligent nanointerface with adjustable hydrophilic and hydrophobic properties is constructed by the supramolecular assembly using a smart ionic liquid molecule. The bionic flexible film possessed the variable hydrophilic-hydrophobic, stimulus responsive, and robust iridescent structural color. The reflective wavelength and the helical pitch of the film can be easily modulated through the ultrasonic energy perturbation strategy. The bionic flexible film by covalent cross-linking has excellent robustness, good elasticity and flexibility. The tunable brilliant structural color of the chiral nanointerface is attributed to the surface charge change of the CNC photonic crystal, which is disturbed by ultrasonic energy perturbation. The bionic flexible film with tunable structure color has intelligent hydrophilic and hydrophobic stimulus response properties. The chiral bionic materials have potential applications in smart skin, optical devices, bionic materials, robots, anti-counterfeiting, colorful displays, and stealth materials.

Incorporation of neodymium, holmium, erbium, and samarium (oxides) in zinc-borotellurite glass: Physical and optical comparative analysis

Investigating the effect of different types of rare-earth oxides on zinc borotellurite glass is important to determine the potential application in optical devices. The addition of rare-earth oxides in zinc borotellurite glass is well-known to enhance the optical properties due to the effects of 4f-4f transitions. In this work, we aim to compare the effect of different rare-earth oxides on zinc borotellurite glass denoted as ZBTNd, ZBTHo, ZBTEr and ZBTSm. The glass samples were successfully fabricated via the melt-quenched technique. The physical investigation of the glasses has been done by measuring the density and molar volume. It was found that ZBTNd glass has the lowest density than the other glasses due to the small atomic radius in neodymium oxide. High-density value for ZBTHo glass shows potential to be used as radiation shielding properties. The high value of molar volume for ZBTNd glass is advantageous for fiber optics as ZBTNd glass has good performance in elasticity. It was found that ZBTEr has a lower refractive index than the other glasses due to low dispersion characteristics. However, ZBTEr glass has good performance to be used in optical communication applications. It was found that the optical absorption shifts to a longer wavelength beginning from ZBTEr > ZBTHo > ZBTNd > ZBTSm. The optical band gap energy for ZBTEr glass is higher than the other glasses due to the Coulomb repulsion energy for erbium which is greater than neodymium and samarium and slightly higher than holmium. The pattern of electronic polarizability for all glasses was found as follows ZBTSm>ZBTNd>ZBTEr>ZBTHo. The optical basicity for ZBTEr was found highest which indicates a higher acidity, meanwhile, the ZBTNd glass has the lowest value which corresponds to a higher basicity.

Studies on the synthesis, growth, and characterization of 2-cyanopyridinium salicylate single crystals for nonlinear optical applications

By employing methanol as the solvent in slow solvent evaporation method, a new nonlinear optical organic single crystal of 2-cyanopyridinium salicylate (2-CPSC) was grown. The lattice parameters of the 2-CPSC crystals were found out to be a = 7.7764(9) Å, b = 12.3938(17) Å, c = 12.3685(18) Å, and β = 94.44º using single crystal X-ray diffraction (SCXRD) analysis. The confirmation of crystalline nature was done by powder XRD analysis. The 2-CPSC crystal's chemical composition and functional groups were confirmed by Fourier transform infrared (FTIR) spectral analysis. The optical study was done by ultraviolet-visible-near infrared (UV–Vis-NIR) spectral analysis showing a cutoff wavelength of 338 nm. Studies on the grown 2-CPSC crystal's dielectric and Vicker's microhardness were also conducted. The linear dependence of photocurrent with the applied electric field was revealed for the grown crystals. The 2-CPSC crystal's third-order nonlinearity was investigated by the single-beam Z-scan technique using a continuous He-Ne laser. The open aperture Z-scan reveals the two-photo absorption mechanism and the closed aperture Z-scan study reveals the positive nonlinearity of the 2-CPSC crystals with third order susceptibility value of χ3=2.6763×10−6(esu). The density functional theory (DFT) method of B3LYP level with the 6–31++G(d,p) basis set was used for different quantum chemical calculations like geometry optimization, natural bond orbital (NBO) analysis, mulliken atomic charge, and molecular electrostatic potential (MEP). The higher nonlinearity of the 2-CPSC can be a potential alternative for commercially available potassium dihydrogen phosphate (KDP) and candidate for its application in nonlinear optical devices like optical limiting and optical switching.