Applications In Optoelectronic Devices Research Articles

Deciphering the role of CIELab on emission mechanism of Samarium (Sm3+) ions embedded boro-tellurite glasses for applications in optoelectronics devices

Deciphering the role of CIELab on emission mechanism of Samarium (Sm3+) ions embedded boro-tellurite glasses for applications in optoelectronics devices

Quantum yield, energy transfer, and x-ray induced study of Sm3+ ions doped oxide glasses for intense orange-red photo-emitting optoelectronic device applications

The work elucidates detailed analysis of X-ray near edge structure of Gd3+ ions using Synchrotron studies and deciphers the energy transfer mechanism involved in the stoichiometric ratio of (79-x)B2O3 + 10ZnO + 10BaO + xGd2O3 + 1Sm2O3 (BZBGS; x = 0, 5, 10, 15, 20 mol.%) glasses. A detailed analysis of the glasses’ optical, structural, and luminescence properties were instigated to understand light emitting behaviour. The oxidation state of Gd atom inside the glass found to be + 3. Stimulated emission cross section, radiative transition probability and branching of the metastable state of rare-earth ions were evaluated using Judd-Ofelt model and compared with other reported literature. Photo-Emission spectra were monitored at the UV-C band and X-rays. Luminescence was analysed with various excitation wavelengths and sources. Photoluminescence quantum yield show more than 22 % efficiency and show more than 15 % compared with other reported glasses. Luminescence intensity ratio was analysed and found that the Sm3+-ions do not occupy the inversion-symmetry which enhances the luminescence intensity in the present glass system. The CIE and CCT values were evaluated and discussed.

Dual-Source Evaporation Processed Novel NaBiS2 Absorber Material for Eco-Friendly and Stable Photovoltaics.

Exploring and developing novel, low-cost, and environmentally friendly photovoltaic materials is a vital trend in the evolution of solar cell technology. The distinctive properties of alkali bismuth ternary sulfides have spurred increased research and application in optoelectronic devices. In this study, a novel method is reported for preparing NaBiS2 film by sequential thermal evaporation of Na2S and Bi2S3 layers followed by heating post-treatment for the first time, as well as the preparation of solar cells with NaBiS2 as the light-absorbing layer. Based on X-ray diffraction and Raman analysis, the prepared NaBiS2 film is confirmed to be a single-phase material, without the presence of any secondary phases. Additionally, the photoelectric characteristics of NaBiS2 are investigated and incorporated this material into solar cell devices. By optimizing the device architecture, the solar cell utilizing NaBiS2 as the light-absorbing layer achieved a photoelectric conversion efficiency of 2.91%, which is the highest efficiency reported for NaBiS2 solar cells up to now. The research has provided a valuable perspective and path for the development of novel photovoltaic materials in the solar cell field.

Progress in in situ TEM investigations of halide perovskites

Halide perovskites (HPs) have found wide-ranging applications in photovoltaic and optoelectronic devices, achieving remarkable success due to their unique crystal structure and properties. Given the sensitivity of perovskite materials to external stimuli, it is crucial to understand the intrinsic changes in structure and chemical composition during operational conditions. This understanding could assist researchers in exploring new strategies to enhance the photoelectrical properties and stability of these materials. While many in situ methods, such as in situ X-ray diffraction and in situ photoluminescence, have been employed to investigate the properties of perovskite materials in real-time, in situ transmission electron microscopy (TEM) stands out as an unparalleled technique for observing subtle changes at the micro and even atomic scale. In this review, we summarize recent advancements in studying HPs using in situ TEM. We first introduce studies on the crystallization process of HP crystals through in situ TEM observation, and then categorize research works on the degradation process of HPs driven by different external stimuli, including electron beam, heat, electrical bias, light, and ambient atmosphere. Finally, we highlight several challenges that still need to be addressed in the future. This review aims to present a thorough summary of the existing research and lay the groundwork for future inquiries in this captivating area.

Detailed structural study, optical, and dielectric properties of Co0.4Ni0.3Zn0.3Fe2O4 ferrite and its potential applications for optoelectronic and electronic devices

Detailed structural study, optical, and dielectric properties of Co0.4Ni0.3Zn0.3Fe2O4 ferrite and its potential applications for optoelectronic and electronic devices

Optical properties of quasi-two-dimensional GaAs/AlGaAs nanosheets prepared by releasing epitaxial layer.

Quasi-two-dimensional nanosheets exhibit novel properties and promising applications in optoelectronic flexible devices. Research on non-layered III-V semiconductor nanosheets has been constrained by their covalent bonding connections. In this study, GaAs/AlGaAs heterojunction nanosheets were prepared by releasing an epitaxial layer, and their optical properties were investigated by adopting steady-state and transient absorption spectroscopy. The optical properties of the independent GaAs/AlGaAs heterojunction were investigated separately in order to exclude the effect of the substrate. This work provides a comprehensive understanding of the physics of III-V semiconductor quasi-two-dimensional nanosheets.&#xD.

Comparative Optical Properties of Amorphous and Crystalline MoO3 Films by Spectroscopic Ellipsometry Study

This paper presents a comprehensive study of the optical properties of amorphous and crystalline MoO3 thin films using spectroscopic ellipsometry. MoO3 films were deposited on SiO2/Si substrates with varying oxide thicknesses using the atomic layer deposition (ALD) method. The study utilized various optical oscillator models, including Lorentz, Tauc–Lorentz and Harmonic, to analyze the dielectric functions and identify midgap states resulting from oxygen deficiencies. The findings highlight significant differences in the optical properties between amorphous and crystalline MoO3 films, demonstrating the impact of structural phases and substrate conditions. Specifically, amorphous films exhibited lower broadening and energy peaks compared to crystalline films, which showed distinct midgap states indicative of higher oxygen vacancy concentrations. These results enhance the understanding of the optical behavior of MoO3 films and their potential applications in advanced optoelectronic devices.

Precise Tailoring of Unprecedent Layered Perovskite-type Heterostructure Ferroelectric via Chemical Molecular Scissor.

Precise stacking of distinct two-dimensional (2D) rigid slabs to build heterostructures has renewed the portfolio of 2D materials, e.g., magic-angle graphene, due to the emergence of exotic physical properties. Recently, single-crystal heterostructures of layered perovskites have emerged as an exciting branch, while it remains scarce to achieve strong ferroelectricity in this new heterostructure family. Here, we present the first ferroelectric of 2D perovskite heterostructures as single crystal, (EA3Pb2Br7)EA4Pb3Br10 (1, EA = ethylamine), by precisely tailoring inorganic sheets via a chemical molecular scissor. It has notable ferroelectricity of large spontaneous polarization (Ps ~ 5.0 μC/cm²) and high Curie temperature (Tc ~ 375 K). Structurally, its inorganic framework adopts a unique 2D heterostructure that contains two different rigid slabs of {EA3Pb2Br7}n and {EA4Pb3Br10}n. This motif is self-assembled by layer-by-layer clipping of rigid prototype sheets, using extra neopentylamine as a molecular chemical scissor. Unlike epitaxial growth, such a molecule-level stacking facilitates the growth of heterostructure single crystals. Combining its strong ferroelectricity and inherent anisotropy, crystal-based device of 1 exhibits an ultrahigh polarized-light sensitivity up to ~37 in self-powered mode, being the highest level of 2D perovskite ferroelectric family. Our work will facilitate the further development of ferroelectric materials for optoelectronic device applications.

2D MXenes: Synthesis, Properties, and Applications in Silicon-Based Optoelectronic Devices.

MXenes, a rapidly emerging class of 2D transition metal carbides, nitrides, and carbonitrides, have attracted significant attention for their outstanding properties, including high electrical conductivity, tunable work function, and solution processability. These characteristics have made MXenes highly versatile and widely adopted in the next generation of optoelectronic devices, such as perovskite and organic solar cells. However, their integration into silicon-based optoelectronic devices remains relatively underexplored, despite silicon's dominance in the semiconductor industry. In this review, a timely summary of the recent progress in utilizing Ti-based MXenes, particularly Ti3C2Tx, in silicon-based optoelectronic devices is provided. The composition, synthesis methods, and key properties of MXenes that contribute to their potential for enhanced device performance are focused on. Furthermore, the latest advancements in MXene applications in silicon-based solar cells and photodetectors are discussed from fundamental and applied perspectives. Finally, the key challenges and future opportunities for the integration of MXenes in silicon-based optoelectronic devices are outlined.

Effect of Ti Doping on the Structural, Electronic, Optical and Thermoelectric Properties of ZrO2: A Systematic DFT Approach

AbstractIn this work, the density functional theory (DFT) calculations in wien2k code to investigate the effect of (Titanium) Ti doping (25% and 50%) in ZrO2 is utilized. The negative values of the Ef, i.e., −2.14, −3.42 and −2.31 as well as energy versus volume curves show the stability of pure, 25% and 50% doped ZrO2. From band structure and density of states results it is confirmed that upon doping Ti, the band gap of ZrO2 become direct from indirect and reduces from 3.10 eV to 1.26(25% doped)/1.16(50% doped). The optical investigations reveal that incorporation of Ti improved the optical properties significantly, which show the significance of these materials for optoelectronic device applications. The thermoelectric properties are investigated using the Boltzmann transport theory. The Seebeck coefficient, electronic conductivity, thermal conductivity, power factor and figure of merit is calculated. The obtained results show that the under study compounds are best candidates for different thermoelectric applications.

Molecular engineering charge transfer and triplet exciton formation in donor-acceptor cocrystals.

Organic donor-acceptor (D-A) cocrystals are gaining attention for their potential applications in optoelectronic devices. This study explores the dynamics of charge transfer (CT) and triplet exciton formation in various D-A cocrystals. By examining a series of D-A cocrystals composed of coronene (COR), peri-xanthenoxanthene (PXX), and perylene (PER) donors paired with N,N-bis(3'-pentyl)perylene-3,4:9,10-bis(dicarboximide) (PDI), naphthalene-1,4:5,8-tetracarboxy-dianhydride (NDA), or pyrene-4,5,9,10-tetraone (PTO) acceptors, using transient absorption microscopy and time-resolved electron paramagnetic resonance spectroscopy, we find that the strength of the CT interaction influences the nature and yield of triplet excitons produced by CT state recombination. In particular, in the PER-PDI, COR-PTO, and PER-PTO cocrystals, localized triplet excitons are lower in energy than the CT state. By contrast, no localized triplet excitons are available to the CT states of the PXX-NDA, PER-NDA, and PXX-PTO cocrystals, and as a result, the CT states rapidly decay to ground state with no triplet formation. Moreover, density functional theory calculations show that the transition between delocalized CT states to a triplet state localized to a single donor or acceptor unit provides the source of spin-orbit coupling necessary when the triplet states are energetically accessible. These findings provide insights into the design of molecular materials with tailored exciton properties for optoelectronic applications.

Electrically Switching Ferroelectric Order in 3R-MoS2 Layers.

Transition metal dichalcogenides (TMDs) with rhombohedral (3R) stacking order are excellent platforms to realize multiferroelectricity. In this work, we demonstrate the electrical switching of ferroelectric orders in bilayer, trilayer, and tetralayer 3R-MoS2 dual-gate devices by examining their reflection and photoluminescence (PL) responses under sweeping out-of-plane electric fields. We observe sharp shifts in excitonic spectra at different critical fields with pronounced hysteresis. These phenomena are attributed to distinct interlayer polarizations resulting from specific lateral displacements between the layers, with each configuration yielding a unique ferroelectric state. Our findings indicate two, three, and four ferroelectric regimes for bilayer, trilayer, and tetralayer structures, respectively, in agreement with theoretical prediction. Moreover, each polarization state can be stabilized at zero applied electric field. The tunable ferroelectric phases of these multilayers pave the way for innovative applications in non-volatile memory, logic circuits, and optoelectronic devices.

Recent progress in two-dimensional polymer materials: interfacial synthesis and applications

Abstract As a new two-dimensional polymer synthetic material, two-dimensional polymers (2DPs) not only have the advantages of high specific surface area and high transparency of two-dimensional materials, but also have the advantages of high mechanical strength and easy processing of polymer materials. Therefore, 2DPs are widely used and have become one of the indispensable materials today. However, there are still challenges in preparing 2DPs using traditional methods. Among the various synthesis strategies, the interfacial synthesis methods with the advantages of simple operation and high crystallinity have become typical method for preparing 2DPs. In this review, we first summarize the types of interface synthesis methods and the latest research progress. Secondly, the 2DPs applications in optoelectronic devices, membrane separation, sensor, electrical device and batteries, etc. are introduced. Finally, we summarize and prospect the existing challenges and future research directions based on the current research status of 2DPs.

Study on the modulation mechanism of the optoelectronic properties based on common electrode metal atom adsorption on graphene/MoTe2.

The two-dimensional graphene/MoTe2 heterostructure holds extensive potential applications in optoelectronic devices, sensors, and catalysts. To expand its optical applications, this study systematically investigates the adsorption stability of metal atoms (Au, Pt, Pd, and Fe) on the graphene/MoTe2 and their influence on its optoelectronic properties employing first-principles methods. The findings indicate that after the adsorption of Au and Pd, the structure retains its direct bandgap properties, while the adsorption of Pt and Fe exhibits indirect bandgap characteristics. The work functions for all adsorbed structures are lower compared to the pristine graphene/MoTe2. The total density of states is primarily derived from the C-2p, Mo-4d, Te-5p orbitals, as well as the d and s orbitals of the adsorbed atoms. The pristine graphene/MoTe2 exhibits significant absorption in the ultraviolet range. Once graphene/MoTe2 is adsorbed by metal atoms, it can significantly enhance the optical absorption across the spectrum from infrared to ultraviolet light. These findings provide important theoretical guidance for regulating the application of graphene/MoTe2 in optoelectronics and related fields. All analyses are grounded in density functional theory first principles and computed using CASTEP. Graphene/MoTe2 consists of 4 × 4 × 1 single-layer, graphene single layer, and 3 × 3 × 1 single-layer MoTe2. To prevent interactions between neighboring unit cells, a 20Å vacuum space in the z-direction is employed. The electronic exchange-correlation interactions are treated using the Perdew-Burke-Ernzerhof functional within the framework of the generalized gradient approximation. Van der Waals (vdW) interactions are incorporated using the vdW correction function proposed by Grimme, which effectively describes vdW interactions. During the simulation, the cutoff energy for plane wave expansion is set to 420eV, and the k-point grid is set to 4 × 4 × 1. The atomic displacement convergence standard is 0.002Å, the internal stress convergence standard is 0.1GPa, and the interaction force convergence standard between atoms is 0.05eV/Å. The convergence threshold for the iteration precision is set to ensure that the total energy for each atom is not less than 2 × 10-5eV/atom.

Raman and Photoluminescence Studies of Quasiparticles in van der Waals Materials.

Two-dimensional (2D) layered materials have received much attention due to the unique properties stemming from their van der Waals (vdW) interactions, quantum confinement, and many-body interactions of quasi-particles, which drive their exotic optical and electronic properties, making them critical in many applications. Here, we review our past years' findings, focusing on many-body interactions in 2D layered materials, including phonon anharmonicity, electron-phonon coupling (e-ph), exciton dynamics, and phonon anisotropy based on temperature (polarization)-dependent Raman spectroscopy and Photoluminescence (PL). Our review sheds light on the role of quasi-particles in tuning the material properties, which could help optimize 2D materials for future applications in electronic and optoelectronic devices.

Enhanced Red Luminescence in Dy3+/Eu3+Co-doped Calcium Alumino Borosilicate Glasses for w-LED Applications.

Dy3+ and Eu3+ co-doped borosilicate glasses have been synthesised via melt quench technique. Amorphous behaviour of the sample has been verified by XRD study. FT-IR analysis confirmed the presence of various bonds in the host lattice. Energy band gap values of the co-doped glasses were estimated from the UV-VIS data via Tauc Plot. Excitation spectra were recorded under 575nm (Dy3+) and 612nm (Eu3+) emission wavelengths of co-doped glasses. Emission spectra of the co-doped glasses under 350nm and 393nm showed a significant shift towards increasing red emission with increasing Eu3+ concentrations. Dexter's theory was applied to study the transfer of energy mechanism between Dy3+ and Eu3+ ions. Time decay curves were plotted for the co-doped glasses for 350nm excitation and 576nm emission wavelength. CIE coordinate diagram shows a shift towards red region with increasing excitation wavelength from 350nm to 465nm. The enhancement of red component with increasing Eu3+ concentrations in the as -prepared borosilicate glasses can be appropriately utilised in various w-LEDs and other optoelectronic devices applications.

Single-Walled ZnSe Nanotubes for High-Performance Photodetectors: A Computational Prediction.

Low-dimensional nanomaterials show great potential for developing semiconducting materials due to their distinct electronic,optical, and mechanical properties. In this study, we constructed various one-dimensional ZnSe nanotubes and investigated their transport and photoresponse properties by using the density functional theory (DFT) and non-equilibrium Green's function (NEGF) method. Under bias regulation, one-dimensional tetragonal ZnSe nanotube curled along the diagonalcan reach a current of 111.3 μA at a bias of 4.0 eV. It is worth noting that for all considered photon energies, thephotocurrent exhibits a cosine dependence on the polarization angle, which is consistent with the photogalvanic effect. The results show that our constructed ZnSe nanotubes have potential for applications in electronic and optoelectronic devices.

Defects Passivation Engineering of Chalcogenide Quantum Dots via In-Situ Fluorination Treatment

Efficient carrier transport through reducing the traps in chalcogenide quantum dots (QDs) is crucial for their application in optoelectronic devices. This study introduces an innovative in-situ fluorination treatment to remove...

The optoelectronic properties of boron nitride nanotubes of armchair (7, 7) and zigzag (12, 0) types: A theoretical study

In this article, the electronic and optical properties of single-walled boron nitride nanotubes (SWBNNTs) in zigzag (12, 0) and armchair (7, 7) configurations were examined using density functional theory (DFT) with the Vienna Ab initio Simulation Package (VASP). The analysis shows that SWBNNTs exhibit electronic characteristics with a density of states and an electronic band gap around 4 eV. Regarding optical properties, the calculations reveal key features such as absorption, reflection, and dielectric constant, with a notably strong absorption peak in the ultraviolet region. These results highlight the potential of SWBNNTs for applications in optoelectronic devices.

Thickness-dependent surface reconstructions in non-van der Waals two-dimensional materials.

Bismuth oxychalcogenides (Bi2O2X, X = S, Se, Te), a family of non-van der Waals (non-vdW) two-dimensional (2D) semiconductors, are attracting significant attention due to their outstanding semiconducting properties and huge potential in various applications of electronic and optoelectronic devices. Surface imperfections (e.g., surface vacancies) and surface reconstructions are more likely to appear and may cause intriguing physical properties and novel phenomena in the non-vdW 2D materials than the vdW cases. Here, we explore the impacts of surface vacancies and surface reconstructions on the properties of the surfaces and 2D structures of Bi2O2X by using the first-principles method. We find that the dimerization of surface X-vacancies occurs in Bi2O2S and Bi2O2Te (001) surfaces, like that happening in Bi2O2Se. Unexpectedly, the electronic structures of Bi2O2X (001) surfaces show strong tolerance to the order of surface X-vacancies. Furthermore, we find a phenomenon of thickness-dependent surface reconstructions for non-vdW Bi2O2X ultrathin films. For a monolayer, the zipper-surface is more stable, while the dimer-surface is generally more stable for thicker films. Calculated exfoliation energies of the Bi2O2X monolayer and multi-layers are close to those of common vdW 2D materials, indicating that 2D Bi2O2X belong to easily fabricated 2D materials, even though the inter-layer binding interaction is of the non-vdW type. Our results suggest that non-vdW 2D materials can possess intriguing properties because of surface imperfections and reconstructions in comparison with vdW 2D materials.