Applications In Optoelectronic Devices Research Articles

Self-Assembly of Photoresponsive Nano Scrolls Produced by Exfoliation of Layered TaWO6.

Novel photoresponsive nano scrolls of tantalotungstate intercalated with C3F7-Azo+ were synthesized by guest-guest ion exchange. Physicochemical characterization utilizing X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) verified the successful synthesis of spiral nano scrolls. XRD and UV data evidenced aggregated conformations of C3F7-Azo+ with end-to-end J-type configurations between the tantalum tungstate layers. The nano scrolls exhibited reversible trans-cis photoisomerization under ultraviolet and visible light irradiation at 365 and 440 nm, respectively, while the basal spacing accompanying the photoresponse was reversibly changed. Overall, photofunctional tantalum tungstate nano scrolls have promising applications in optoelectronic devices.

Intertwined Flexoelectricity and Stacking Ferroelectricity in Marginally Twisted hBN Moiré Superlattice.

Moiré superlattices in twisted van der Waals homo/heterostructures present a fascinating interplay between electronic and atomic structures, with potential applications in electronic and optoelectronic devices. Flexoelectricity, an electromechanical coupling between electric polarization and strain gradient, is intrinsic to these superlattices because of the lattice misfit strain at the atomic scale. However, due to its weak magnitude, the effect of flexoelectricity on moiré ferroelectricity has remained underexplored. Here, the role of flexoelectricity in shaping and modulating the moiré ferroelectric patterns in twisted hBN homojunction is unveiled. Enhanced flexoelectric effects induce unique stacking ferroelectric domains with hollow triangular structures. Interlayer bubbles influence domain shape and periodicity through local electric field modulation, and tip-stress enables the reversible manipulation of domain area and polarization direction. These findings highlight the impact of flexoelectric effects on moiré ferroelectricity, offering a new tuning knob for its manipulation.

Highly efficient red emission of CsPbBrI2 quantum dots glasses modified by Nb5+ for light-emitting application

Red-emitting perovskite quantum dots (QDs) have significant potential for application in optoelectronic devices. However, their application is hindered by preparation challenges and low photoluminescence quantum yield (PLQY). In this study, CsPbBrI2 red-emitting QDs with a PLQY of up to 58.73 % were synthesized in germanium borate glass. The experimental results indicated that the addition of Nb5+ can not only partially replace the Pb2+ sites but also passivate halogen defects in QDs, enhance radiative transitions, and significantly improve the lattice ordering of CsPbBrI2 QDs glass. Additionally, the incorporation of Nb2O5 supplies free oxygen, facilitating the conversion of [BO4] to [BO3] in the glass network, which results in a looser structure conducive to crystallization. Moreover, the Nb5+-doped CsPbBrI2 QDs glass demonstrated excellent hydrothermal stability. The QDs glass exhibiting the highest luminescent performance was subsequently combined with an InGaN blue chip to create a WLED with a color rendering index (CRI) of 82.7. This study offers an innovative methodology for synthesizing perovskite QDs glass materials with enhanced red emission efficiency through transition metal doping, highlighting their significant potential for practical applications in WLEDs.

Amorphous to Polycrystalline Phase Transition of In Situ Annealed Ge Films: Structural, Morphological, Optical, and Electrical Characteristics

AbstractRadio Frequency (RF) sputtered germanium (Ge) thin films were deposited on glass substrate at in situ annealing temperatures of 400, 450, 500, 550, and 600 °C. X‐ray diffraction (XRD) and Raman spectroscopy revealed that the Ge films were initially amorphous but transformed to polycrystalline after annealing at 450 °C. Further annealing up to 600 °C resulted in improved crystallinity. Strain studies of the films using XRD and Raman showed compressive (out‐of‐plane) and tensile (in‐plane) strains, respectively, throughout all the annealing temperatures. The surface morphology of the films was recorded using atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), which showed grain growth with annealing temperatures. The optical energy gap evaluated from absorption spectra for crystalline films decreased with annealing temperature, indicating improvement in crystallinity of films. The resistivity of the films deduced using current‐voltage measurements was found to decrease with annealing temperature, which can be attributed to enhancement in grain size. This study establishes a correlation between strain, grain size, optical energy gap, and electrical resistivity with temperature for Ge films deposited on glass substrates. Thus, the present study provides insights into variation in physical and electrical properties of films with in situ annealing temperature for their applicability in optoelectronic devices.

Potential harnessing of the semi-organic single crystal of l-alanine potassium bromide (LAPB) from a structural, optical, and thermal perspective for application in optoelectronic devices

Potential harnessing of the semi-organic single crystal of l-alanine potassium bromide (LAPB) from a structural, optical, and thermal perspective for application in optoelectronic devices

Structural, electronic, optical and thermoelectric properties of FrSnI3-xClx (X=0, 1, 2, 3) perovskites using the TB-mBJ approach

Mixed halide inorganic perovskites represent a significant advance in energy conversion materials, with research on these materials paving the way for more sustainable and accessible energy solutions. In this work we investigated the effects of chlorine atom substitution on the structural, electronic, optical and thermoelectric properties of mixed halide perovskites FrSnI3-xClx (x=0, 1, 2, 3). The FP-LAPW approach within the Wien2k package has been employed, using the modified Becke-Johnson potential (TB-mBJ) for the exchange correlation functionals. For FrSnI3 and FrSnCl3 the calculated lattice parameters are in good agreement with theoretical results.The formation energies calculated for FrSnI3-x Clx (x = 0, 1, 2, 3) confirm the thermodynamic stability of all these materials. Analysis of the electronic properties, including partial density of states (PDOS), total density of states (TDOS) and band structures, indicates that these materials exhibit p-type semiconductor behaviour with direct band gaps ranging from 1.169 to 1.953 eV. In terms of optical properties, the FrSnI3-xClx compounds exhibit high optical absorption (α(ω) > 104 cm−1) in the visible region. The broad absorption range extends from visible to ultraviolet energy. The low reflectivity values observed (below 30%) and their minimal energy loss suggest potential applications in optoelectronic devices. The thermoelectric properties of these materials were also studied over a temperature range of 100 to 950 K. They exhibit high Seebeck coefficients, high electrical conductivity, and low thermal conductivity. Notably, at room temperature, FrSnI2Cl and FrSnICl2 show the highest figures of merit, reaching 1.31 and 0.61, respectively, demonstrating their high efficiency for thermoelectric devices

Analysis and simulation of opto-electronics characterization of two-dimensional Janus monolayers for energy applications

First-principles simulations are conducted to investigate the absorption and optoelectronic efficacy of molybdenum–sulfur–selenium, referred to here as MoSSe, and molybdenum–sulfur–oxygen, referred to here as MoSO, Janus monolayers. The materials MoSSe and MoSO demonstrate characteristics of semiconductors, as they possess bandgaps of 2.00 eV (direct) and 1.61 eV (indirect), respectively. This property renders them highly suitable for efficient light absorption. The efficiency of absorption of the device was calculated for the MoSSe and MoSO families, leading to the observation that these material families demonstrate a broad absorption range spanning from the infrared to the ultraviolet regions of the electromagnetic spectrum. This finding represents a novel discovery. Furthermore, the design as a topmost cell is particularly attractive due to its exceptional device absorption efficiency and broader bandgap. This particular family ensures that its band edges remain in alignment with the water-redox potentials. Molybdenum sulfide and molybdenum selenide exhibit promising potential as photocatalysts and in optoelectronic device applications. This is attributed to their appealing photocatalytic properties and notable efficiency in absorbing light for the purpose of water splitting.

Vertical stacking approach for tailoring electronic and optical properties of ultrathin two-dimensional vdW heterostructures of P-MAB (M=Ti, Zr, Hf; A=S, B=Se)

The vertical staking in the form of hetersotructures, is an effective way to enhance the performance of corresponding isolated monolayers. Strong interactions between Janus monolayers (MAB) and Phosphorus (P) monolayers result in significant improvements in both physical and chemical properties compared to single layer configurations. Using first- principle (hybrid) calculations, we explore electronic structure and optical properties of P-MAB (M = Ti, Zr, Hf; A = S, B=Se) van der Waals heterostructures, for potential applications in electronic and optoelectronic devices. Ab initio molecular dynamic (AIMD) simulations confirm the thermal stability, while phonon spectra confirm the dynamical stabilities of these systems. Our analysis reveals that all configurations maintain semiconducting nature with an indirect bandgap. The type-II band alignment in the P-MAB heterostructures is demonstrated through calculations of the partial density of states (PDOS). Bader charge analysis and planar-averaged charge density differences indicate an electron transfer from the P monolayers to the MAB monolayer. Furthermore, our investigation of the dielectric function ϵ2(ω) shows that the lowest energy shift are primarily influenced by excitonic effects.

Investigation of high-detectivity self-powered photodetectors of Rubrene/Bi2Se3 hybrid Van der Waals heterojunction

This paper investigates the Vander Waals heterostructure of organic rubrene and topological insulator Bi2Se3 with an atomically abrupt interface with exciting applications in electronic and optoelectronic devices. This organic/inorganic heterostructure (OIH) was prepared using a simple two-step physical vapor deposition process; based on this hybrid structure, a self-powered photodetector was then constructed. The Dirac surface state at the heterointerface enhances the splitting and transferring of photo-generated carriers, resulting in improved device characteristics. Under 1064 nm, the prepared photodetectors demonstrated a maximum responsivity (6.37 A/W), a high detectivity (3.42 × 1010 Jones), and ultrafast photoresponse speeds with rise time (1.17 µs) and decay time (1.59 µs), respectively. These promising results suggest that these PDs can be used in various photodetection applications and may lead to developing new devices.

Exploring the Impact of Elevated Pressure on the Structural Dynamics of TlInS2 Crystal (I): A First-Principles Investigation with XRD, Raman, and Hirshfeld Topology

The structural dynamics of Thallium Indium Disulfide (TlInS2) crystal under elevated pressures were comprehensively investigated using a combination of X-ray diffraction (XRD), Raman spectroscopy via first-principles calculations, and Hirshfeld surface (HS) analysis. This study aims to elucidate pressure-induced modifications in the crystal structure and their associated properties of TlInS2 crystal. The findings reveal significant structural transformations as pressure increases, with XRD patterns indicating lattice compression and a critical transition from semiconductor to conductor at pressure P=6.25GPa [42]. The calculations predict a reduction in bond lengths, specifically S1-In1 and S1-Tl2, alongside a corresponding decrease in lattice parameters and unit cell volume. Raman spectroscopy corroborates these changes through shifts in phonon modes. The HS analysis provides further insights into pressure-dependent alterations in intermolecular interactions, revealing changes in voids and surface characteristics. The data gained from TlInS2's structural behavior under pressure, contributing to the optimization of its functional properties for pressure-tunable applications in high-performance electronic and optoelectronic devices.

Pr2CuO4/MWCNT/MXene/PANI: A Novel Quaternary Composite with Tunable Properties for Potential Applications in Optoelectronics and Energy Storage Devices

Pr2CuO4/MWCNT/MXene/PANI: A Novel Quaternary Composite with Tunable Properties for Potential Applications in Optoelectronics and Energy Storage Devices

Structural, optical, and dielectric properties of Mn-doped Ce1-xMnxO2 nanocrystals for frequency-dependent device applications

Cerium oxide (CeO2) is a significant oxide semiconductor known for its advantageous electrical, optical, and dielectric properties. This study investigates the effects of manganese (Mn) doping on the structural, optical, and dielectric characteristics of CeO2. Pure and Mn-doped Ce1-xMnxO2 nanocrystalline powders, with Mn concentrations of 0, 1, 3, 5, and 7 %, were synthesized using a co-precipitation method. Structural analysis confirmed the formation of a cubic crystal structure, while surface morphology revealed agglomerated spherical particles. Notably, the band gap of Ce1-xMnxO2 decreased from 2.80 eV to 2.30 eV with increasing Mn content, indicating enhanced electronic properties due to doping. The dielectric properties exhibited a pronounced frequency dependence, with significant variations in dielectric constant and loss, demonstrating the potential of Mn-doped CeO2 as a diluted magnetic semiconductor. These findings underscore the material's applicability in biosensors and optoelectronic devices, paving the way for advancements in frequency-related technologies.

Dielectric relaxation and electrical conduction mechanism via hopping of polarons in (Pb0.3Bi0.7)(Zn0.1Nb0.2Fe0.7)O3 perovskite compound: A study based on CBH model

This work analyses the dielectric and conducting properties of the PZN-modified BF solid solution (0.3PZN-0.7BF) synthesized at 850 °C by solid-state reaction. The Rietveld refinement of 0.3PZN-0.7BF solid solution displays three phases: tetragonal Pb(Fe0.5Nb0.5)O3 (76.68 %), α-BZN (21 %), and Bi2Fe4O9 (2.32 %). Dielectric parameter frequency dispersion implies normal ferroelectricity. Thermal relaxation shifts dielectric loss, imaginary impedance (Z''), and loss modulus (M'') peaks to higher frequencies. Electrical investigation indicates electrode polarization, dipole orientation, charge ordering, oxygen vacancies, and defects. Investigations suggest p-type polarons dominate conductivity. At room temperature and 1 MHz, the compound has 117 dielectric constant and 0.009 tangent loss. Conductivity and impedance testing show semi-conductivity. UV–Vis spectrum investigation shows a 1.97 eV energy band gap, supporting its semiconductor properties. Photovoltaic and optoelectronic device applications benefit from 0.3PZN-0.7BF solid solution optical and electrical property studies.

Structural, electronic and optical properties of Halogen (F and Cl) atoms doped Graphdiyne

Abstract This paper reports the results of a density functional theory investigation of structural, electronic, and optical properties of halogen (fluorine and chlorine) atoms doped graphdiyne. Graphdiyne is doped with fluorine and chlorine with three different doping configurations each where one, two and three atoms of fluorine and chlorine were doped into Graphdiyne at benzene ring and acetylene linkages. The most stable doped structure was determined using the results of formation energy. Monolayers for fluorine and chlorine doped graphdiyne uniformly display metallic characteristics except where two atoms were incorporated shows semiconductor characteristics. PDOS shows that the energy band near the Fermi level is mainly contributed by the C 2p orbitals. Doped configurations shows higher peak intensities and good absorption in the UV, visible light region and IR region. These findings offer a fundamental basis for the understanding and manipulation of electrical and optical properties for doped graphdiyne with halogen atoms atoms and it is suitable for promoting the potential application of graphdiyne based electronic and opto-electronic device applications operating mainly in infrared and ultraviolet range.

Aluminum antimony alloy overlayers synthesized using the electrodeposition method: investigation of structural, optical, electrical properties, and DFT calculation

Abstract This paper presents the synthesis of aluminum antimony (Al–Sb) alloy overlayers using an electrodeposition method for application in optoelectronic devices with various applied constant voltages (2, 4, 6, 8, and 10 V) controlled by a DC power supply. The corresponding energy dispersive x-ray spectroscope spectra show that elements including Al, Sb, and Cl were detected in the layers under all conditions of the applied voltage. The structural properties of the formulated compound layers were studied for their structural properties through x-ray diffraction patterns, and all the diffraction peaks exhibited a cubic phase structure. The Al–Sb alloy overlayers were incorporated with nanoparticles and had crystallite sizes ranging from ∼55 to 282 nm. The average transmittance T(λ) values in the visible to near-infrared region were ∼28.36%, 17.64%, 14.07%, 7.83%, and 5.84%, while the average reflectance R(λ) values were ∼3.80%, 1.69%, 1.30%, 0.47%, and 0.21% for applied voltages of 2–10 V, respectively. The energy band gap (E g) existing in the overlayers was determined using Tauc’s plot with the Kubelka–Munk function and it was inferred to be between 1.90 eV and 2.72 eV. The dispersion constants and energies of the prepared samples were also investigated. The 2 V applied voltage-treated Al–Sb alloy overlayers showed the highest average χ(1), χ ( 3 ) , and n 2 values of 0.088, 1.680 × 10−14 esu., and 4.082 × 10−13 esu., respectively. In addition, the resistance at various absolute temperatures was also recorded for the activation energy (E AC) values of the Al–Sb alloy overlayers with applied voltages of 2–10 V. Finally, ab initio calculations based on density functional theory were performed to support the experimental report of the Al–Sb systems. It was found that the calculated lattice constants are in good agreement with the experimental results, and a wider photoabsorption range performance for Al–Sb phase I in the axis of energy seems to be suitable for application as an optical device.

Chemical Vapor Deposited Thin Palladium Sulfide Crystals for Highly Photoresponsive Photodetector

AbstractNonlayered palladium sulfide (PdS) is of interest due to its rich physical properties and promising applications in optoelectronic devices. However, the growth of thin nonlayered PdS remains challenging because of its intrinsic 3D lattice structure. Here, the first demonstration of the direct synthesis of thin rectangular PdS ribbons/flakes on SiO2/Si substrates by a facile chemical vapor deposition (CVD) approach is presented. The atomic structure and high crystalline quality of CVD‐derived PdS crystals are shown by scanning transmission electron microscopy. The nonlinear saturable absorption and absorption enhancement are revealed by using ultrafast optical pump‐probe spectroscopy, and the photocarrier dynamics present the hot phonon bottleneck and Auger recombination effects. Additionally, the Raman vibration modes display the polarization‐dependent properties verified by angle‐resolved polarized Raman spectroscopy. Importantly, the photodetector based on PdS ribbon demonstrates a decent photoresponsivity of ≈7.7 × 103 A W−1. This results provide an effective way to form thin nonlayered PdS with potential applications in the field of photodetection.

An Examination of the Electronic, Optical, and Thermodynamic Properties of Β-Gan

The current work involves the systematic examination of the features of Gallium Nitride (GaN) including the electronic, optical, structural, and thermodynamic features, depending on first principles calculation. This is according to approximations, (LDA), (GGA), and (m-GGA). The bandgap energies of Gallium nitride are (1.85 eV, 1.93 eV, and 2.179 eV), respectively. Furthermore, our study also reveals that GaN has a direct bandgap and is highly stable. Finally, our results indicate that the m-GGA method accurately predicts the bandgap energy of GaN. The m-GGA method outperforms both LDA and GGA methods in accuracy to predict the bandgap energy of GaN, as evidenced by its closest approximation to the experimental value. To determine the orbital nature of the Gallium and Nitrogen atoms, the state density and state partial density of Gallium nitride were simulated. The absorption coefficient of Gallium nitride is computed and analyzed in depth for the optical transitions. The absorption coefficient of Gallium nitride is affected by various factors, including the material's band structure, temperature, doping level, and the energy of the incident photons. In addition to that, the thermodynamic properties that can be calculated like enthalpy, entropy, heat capacity, free energy, and Debye temperature enable us to understand the thermal behavior of the compound better. The heat capacity of α-GaN is detected to be (39.9, 25.5, and 32.4) Jmole-1K-1, and a Debye temperature of 807 K, 1134 K, and 866 K for LDA, GGA, and m-GGA, respectively. This research will offer a detailed interpretation of β-GaN, covering all its basic properties and possible applications in electronic devices and optoelectronic devices. The results of this study are very important and the new technologies that will be developed based on the Cubic phase - GaN research will be very beneficial.

Glutaraldehyde (GA) crosslinked PVA/GO-Ag polymer nanocomposite for optoelectronic and optomechanical applications

We report on the fabrication of Glutaraldehyde (GA) crosslinked PVA/GO-Ag nanocomposite (PVA/GO-Ag/GA) via in situ thermal reduction. A careful and systematic investigation on PVA, PVA/GO, PVA-Ag, PVA/GO-Ag, and PVA/GO-Ag/GA nanocomposites has been explicitly conducted to exemplify the GA influence on enhancing the PVA/GO-Ag composite's structural, optical, and functional properties. Finite Difference Time Domain (FDTD) simulations validate the experimental results by scrutinizing the compositional, morphological, and positional influence of Ag nanoparticles (NPs) in the polymer matrix in a systematic and comprehensive manner. The optical transmittance of PVA/GO-Ag/GA is enhanced up to 51 % (increased by ∼ 89 %, 21 %, and 42 % of PVA/GO, PVA-Ag, and PVA/GO-Ag, respectively) due to the GA cross-linker. The band gap of PVA/GO-Ag/GA was found to be 5.289 eV, which is the lowest of the composites mentioned above. PVA/GO-Ag/GA exhibits enhanced dc conductivity of 17.3 × 10−9 Sm−1. Above measured values of transmittance, optical band gap, and electrical conductivity demonstrate that the fabricated GA crosslinked PVA/GO-Ag nanocomposite is an excellent candidate in terms of its applicability in multispectral imaging, optoelectronic, and optomechanical devices.

Room‐Temperature Lasing of Dual‐Metal Nanoparticle Surface Lattice Resonance with Monolithic InGaAs Multiple Quantum Wells on GaAs Substrates

This study demonstrates the surface lattice resonance (SLR) laser utilizing asymmetric dual‐metallic nanoparticle arrays, incorporating a high‐refractive‐index material, which exhibits a confinement factor of 16%, enhancing the coupling between metal and dielectric materials. Multiple quantum wells (MQWs) are integrated with plasmonic SLR in the proposed structure. Through theoretical design and experimental validation, the MQW plasmonic SLR laser exhibits excellent high Q‐factor and stable operation at room temperature. This demonstration enhances laser performance and achieves low‐threshold operation with a laser threshold as low as ≈2.39 MW cm−2. This study's design of plasmonic SLR lasers further advances the realization of optoelectronic device applications.

Polaron formation via doping process in an organic semiconductor polymer based on thiophene-phenylene

In this research, we synthesized and analyzed the polymer 5-(5-(10-chlorodecyloxy)-2-methoxy-4-(5-methylthiophen-2-yl)phenyl)-5′-(2-(2-ethylhexyloxy)-5-methoxy-4-(5-methylthiophen-2-yl)phenyl)-2,2′-bithiophene (PTBT46). The polymer was dissolved in chloroform and subjected to gamma radiation doses ranging from 0 to 100 Gy (gray). We observed that PTBT46 can be doped with H+ions, as indicated by visible color changes, optical measurements, and a tenfold increase in conductivity. When analyzing PTBT46 in solution using THF (tetrahydrofuran) and chloroform, we found a notable solvent dependence. In chloroform, new absorption bands appeared at approximately 680 nm and 2630 nm after radiation doses of 25 to 100 Gy, which were not present in THF. These bands are attributed to polarons and bipolarons resulting from the doping process. Additionally, we observed a spectral “blue shift” with increasing H+concentration due to changes in molecular conjugation, without degradation of the polymer chain. This shift, confirmed by Fourier-transform infrared (FTIR) spectroscopy, is reversible and suggests potential applications in optoelectronic devices and advanced radiation sensors.